Progressive hole protection device and hole protection method based on layered compaction

Abstract

This invention discloses a progressive borehole protection device and method based on layered compaction, belonging to the field of borehole head configuration. The method involves controlling the drilling rig to drill to a preset depth, then lowering the borehole protection device to the borehole head for positioning. A drive motor is activated to rotate a hollow drum, and scrapers scrape waste material into the drum. The waste material, under centrifugal force, is discharged from the waste outlet and evenly distributed around the borehole wall, forming a single-layer borehole protection material. Simultaneously, an adjustable nozzle sprays a curing agent downwards to mix with the waste material, forming a solidified borehole protection layer. The controller calculates the target pressure force based on the estimated density, temperature, humidity, and borehole wall pressure after fusion. A hydraulic control valve group controls each telescopic pressure head to adaptively compact the borehole protection layer. Layer by layer, a multi-layer progressive borehole protection structure is formed. This invention efficiently utilizes waste material, rapidly forms the borehole protection structure, improves the density and uniformity of the borehole protection layer, and enhances the borehole protection effect and reliability.

Description

Technical Field

[0001] This invention relates to the technical field of borehole head configuration, specifically to a progressive borehole protection device and method based on layered compaction. Background Technology

[0002] In today's engineering construction field, down-the-hole drilling rigs are widely used in various drilling operations, such as mining, building foundation construction, and tunnel excavation. During drilling, borehole stability has always been a key issue affecting project progress and quality. After traditional drilling operations are completed, the lack of effective borehole protection measures makes the borehole wall susceptible to collapse due to various factors. In areas with complex geological conditions, especially in clay-rich strata, the borehole wall is highly prone to instability due to the properties of clay. Clay expands and softens when it comes into contact with water, causing the borehole wall to lose its original support. External environmental factors, such as rainwater erosion and the compaction caused by construction machinery, can also damage the drilled borehole, thus affecting the smooth progress of subsequent construction operations.

[0003] Currently, while some drilling rigs on the market are equipped with borehole protection devices, they generally suffer from numerous defects. A large amount of waste generated during drilling using existing devices cannot be effectively utilized and needs to be transported and disposed of, increasing construction costs and environmental burden. Simultaneously, existing devices lack effective monitoring and control methods for the density of the borehole protection layer. The compaction process of the protection material relies mainly on fixed compaction parameters, unable to dynamically adjust according to changes in actual construction conditions, resulting in unstable density and difficulty in guaranteeing the borehole protection effect. During drilling, ambient temperature and humidity change with time and drilling depth, and the formation pressure conditions around the borehole wall also vary. However, existing devices typically use fixed process parameters and cannot adaptively adjust to changes in environmental factors such as temperature, humidity, and borehole wall pressure. Temperature changes affect the reaction rate of the curing agent and the mechanical properties of the protection material; humidity changes affect the moisture content and compactability of the protection material; and changes in borehole wall pressure reflect differences in formation constraint conditions. All these factors significantly impact the borehole protection effect. Due to a lack of adaptive adjustment capabilities to environmental changes, existing technologies exhibit poor consistency in borehole protection quality under varying construction conditions, making them ill-suited to complex and ever-changing construction environments. Regarding sensor data processing, while existing borehole protection devices are equipped with various sensors to monitor construction parameters, these sensors are inevitably subject to noise interference in actual working environments, resulting in significant fluctuations and errors in the raw measurement data. Directly using this data leads to frequent changes in control parameters, affecting the stability of the borehole protection process. In terms of compaction control, existing devices either do not perform compaction or employ a fixed compaction force control method, applying a constant compaction force throughout the entire process. Under certain conditions, this may lead to insufficient compaction, failing to achieve the desired density, while under other conditions, it may result in excessive compaction, causing deformation or cracking of the borehole protection layer. Furthermore, existing devices lack precise control over the uniformity of compaction in the circumferential direction. Deviations in the applied compaction force at different compaction points result in uneven density distribution of the borehole protection layer in the circumferential direction, creating localized weak areas and affecting the overall strength and stability of the borehole protection structure. In terms of construction methods, existing hole protection technology typically employs a one-time molding process to form a thicker hole protection layer, achieving a relatively large hole protection structure in a single operation. However, due to the limited compaction capacity of the compaction equipment, thicker hole protection layers often suffer from insufficient surface compaction while the interior remains under-compacted, resulting in loose areas within the hole protection layer and reducing the overall quality of the hole protection structure.

[0004] Therefore, it is necessary to design a drilling rig hole protection device and hole protection method to solve the problems existing in the above-mentioned prior art, improve the density and uniformity of the hole protection layer, enhance the adaptability and reliability of the hole protection structure in different construction environments, and meet the drilling hole protection requirements under complex geological conditions. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides a progressive hole protection method based on layered compaction, comprising the following steps:

[0006] S1. Drilling and Equipment Positioning: After the drilling rig has drilled to the preset depth, the hydraulic drive cylinder is controlled to adjust the lifting slider to move along the guide rail, so that the hollow rotary drum moves down to the borehole opening to complete the positioning.

[0007] S2. Waste collection and discharge: The drive motor is started and the hollow drum is driven to rotate through the meshing of the drive gear and the driven gear. The scraper at the bottom of the lower drum scrapes the waste into the hollow drum. The waste is discharged from the waste outlet under the action of centrifugal force and is evenly distributed around the borehole wall to form a single layer of hole protection material.

[0008] S3. Curing agent spraying: While the waste is being discharged, the adjustable nozzle in the upper cylinder sprays the curing agent downwards, and the curing agent mixes with the waste to form a cured protective layer.

[0009] S4. Multi-sensor data fusion: The data acquisition unit collects detection data from density sensor, temperature sensor, humidity sensor, orifice wall pressure sensor and pressure sensor. The PLC controller uses an extended Kalman filter algorithm to fuse the multi-sensor data and outputs the fused state estimate.

[0010] S5. Multi-parameter coupling adaptive compaction: The PLC controller calculates the target compaction force of multi-parameter coupling based on the estimated values ​​of the fused density, temperature, humidity and borehole wall pressure. The hydraulic control valve group controls the hydraulic cylinder of each telescopic pressure head to drive the compaction head to extend radially and adaptively compact the protective borehole layer.

[0011] S6. Device moving upward and cyclic construction: After compaction is completed, control each telescopic pressure head to retract, and use the hydraulic drive cylinder to move the hole protection device upward by a preset distance. Repeat steps S2 to S5.

[0012] S7. Complete the hole protection: Repeat steps S2 to S6 to accumulate layers to form a multi-layer progressive hole protection structure until the preset total height is reached.

[0013] Furthermore, in step S1, the single drilling depth is set according to the formation type, the drilling rig is controlled to stop after drilling to the set depth, and then the hydraulic drive cylinder is controlled to extend and retract to move the hollow rotary drum downward so that the scraper is located in the waste accumulation area at the borehole opening.

[0014] In step S2, the rotation speed of the hollow drum is set to 20 rpm to 40 rpm. After the waste material is discharged from the waste outlet, a single layer of protective material is formed, with a single layer thickness δ of 20 mm to 50 mm.

[0015] In step S3, the amount of curing agent sprayed is calculated based on the volume of the single-layer protective material layer. The calculation formula is: ;in, The amount of curing agent sprayed (L); Pi; The outer diameter of the protective layer (m); The inner diameter of the protective layer (m); The thickness (m) of a single layer of protective hole material; The volume ratio of curing agent to waste material should be between 0.25 and 0.40; control the adjustable nozzle to spray at the calculated rate. Perform the spraying.

[0016] Furthermore, step S4 includes the following sub-steps:

[0017] S41. The data acquisition unit acquires the raw measurement values ​​of each sensor at a fixed sampling period to form an observation vector. ;

[0018] S42. The PLC controller estimates the state posterior value from the previous cycle. Obtain the prior state estimate for the current period ;

[0019] S43. Calculate the prior covariance matrix The calculation formula is: ;in, for The prior covariance matrix at time t; for The posterior covariance matrix at time t; The process noise covariance matrix;

[0020] S44. Calculate the Kalman gain matrix. The calculation formula is: ;

[0021] in, for Kalman gain matrix at time step; The prior covariance matrix; The observation matrix; for The transpose of the matrix; To observe the noise covariance matrix; Invert a matrix;

[0022] S45. Update the state based on the Kalman gain matrix, calculated using the following formula: ;in, for The posterior estimate of the state at time 1; These are prior state estimates; The Kalman gain matrix; The observation vector is used; the output is the fused state estimate, including the density estimate. Temperature estimate Humidity estimates and estimated borehole wall pressure ;

[0023] S46. Update the posterior covariance matrix The calculation formula is: ;in, for The posterior covariance matrix at time t; It is the identity matrix; The Kalman gain matrix; The observation matrix; The prior covariance matrix is ​​used; after completing one filtering cycle, return to step S41 to enter the next cycle.

[0024] Furthermore, step S5 includes the following sub-steps:

[0025] S51. The PLC controller receives the fused state estimate output from step S4, including the density estimate. Temperature estimate Humidity estimates and estimated borehole wall pressure ;

[0026] S52. Calculate the temperature correction factor The calculation formula is: ;

[0027] in, This is a temperature correction factor; The estimated temperature after fusion (°C); 0.02 is the reference temperature (°C); 10 is the temperature normalization coefficient (°C);

[0028] S53. Calculate the humidity correction factor The calculation formula is: ;in, This is the humidity correction factor; The estimated humidity value (%) after fusion; 0.15 represents the optimal humidity (%); 0.15 is the humidity influence coefficient.

[0029] S54. Calculate the correction factor for borehole wall pressure. The calculation formula is:

[0030] ;in, This is the correction factor for the borehole wall pressure; This is for calculating the minimum value; This is for calculating the maximum value. This represents the estimated pressure (kPa) on the fused pore wall. The reference borehole wall pressure (kPa) is 0.1; the borehole wall pressure influence coefficient is 0.8; the lower limit of the correction coefficient is 1.2;

[0031] S55. Calculate the target pressure force The calculation formula is: ;in, Apply force (kN) to the target; The baseline compressive strength (kN); For target density; This is the current density estimate after fusion; This is a temperature correction factor; This is the humidity correction factor; This is the correction factor for the borehole wall pressure;

[0032] S56. The hydraulic control valve assembly is based on the target pressure. The hydraulic cylinders are controlled to move synchronously, driving the compaction head to extend radially and apply pressure to the protective hole layer. The pressure sensor detects the actual pressure in real time. The PLC controller adjusts the output of the hydraulic control valve group through closed-loop control to achieve the actual pressure. Tracking target pressure force After reaching the target, maintain the compaction state for 5 to 20 seconds to complete the compaction.

[0033] Furthermore, in step S6, after compaction is completed, the hydraulic control valve group controls the piston rods of each hydraulic cylinder to retract, and then controls the hydraulic drive cylinder to contract, causing the hole protection device to move upward along the guide slide rail, with an upward movement distance of... The calculation formula is: ;in, The upward movement distance of the device (mm); The thickness (mm) of a single layer of protective hole material; The interlayer overlap (mm) is a value that is taken from the value of the layer overlap. 15% to 30%;

[0034] In step S7, the total height of the hole protection structure Based on the number of completed layers The calculation formula is as follows: ;in, The total height of the hole protection structure (mm); This represents the number of completed protective layers. The upward movement distance for a single layer is (mm). The thickness of a single-layer protective material layer (mm); when The construction cycle will stop when the preset total height is reached.

[0035] The present invention also provides a progressive hole protection device based on layered compaction, comprising:

[0036] The lifting and adjusting mechanism includes a back plate fixed on the drilling rig, a guide rail fixed on the back plate extending vertically, a lifting slider slidably connected to the guide rail, and a hydraulic drive cylinder with its cylinder body fixed on the back plate and its piston rod connected to the lifting slider.

[0037] The hole forming assembly includes a support frame fixed on a lifting slider, a hollow rotating cylinder rotatably connected to the support frame, and a drive motor fixed on the support frame. The hollow rotating cylinder includes an upper cylinder and a lower cylinder fixedly connected. A driven gear is fixed on the rotating shaft at the top of the upper cylinder, and a driving gear on the output shaft of the drive motor meshes with the driven gear. An adjustable nozzle is installed in the nozzle mounting chamber on the inner wall of the upper cylinder. A waste outlet is opened on the side wall of the lower cylinder, and a scraper is fixed at the bottom of the lower cylinder.

[0038] The layered compaction mechanism includes a compaction ring fixed to the bottom of the lower cylinder and telescopic pressure heads distributed along the circumference of the compaction ring; the telescopic pressure head includes a hydraulic cylinder body fixed radially on the compaction ring and a compaction head installed at the front end of the piston rod of the hydraulic cylinder body;

[0039] The sensor system includes a pressure sensor mounted on the telescopic pressure head, a compaction sensor mounted on the compaction ring, a temperature sensor, a humidity sensor, and a borehole wall pressure sensor.

[0040] The control system includes a data acquisition unit, a PLC controller, and a hydraulic control valve group. The data acquisition unit is electrically connected to each sensor to acquire detection signals. The PLC controller is electrically connected to the data acquisition unit, the hydraulic drive cylinder, the drive motor, the control valve of the adjustable nozzle, and the hydraulic control valve group. The PLC controller has a built-in extended Kalman filter algorithm module for multi-sensor data fusion and a built-in multi-parameter coupled pressure force calculation module for calculating the target pressure force. The hydraulic control valve group is connected to each hydraulic cylinder to control the movement of the telescopic pressure head.

[0041] In a preferred embodiment, the rotating shaft is located at the center of the top of the upper cylinder and is mounted on the support frame via a bearing seat; the nozzle mounting chambers are distributed along the circumference of the upper cylinder, and the spray direction of the adjustable nozzles is downward; the waste outlet is distributed along the circumference of the lower cylinder and extends axially to form a strip-shaped opening; the scraper is distributed along the circumference of the lower cylinder and extends radially outward.

[0042] A dustproof flange is installed at the joint between the shaft of the hollow rotary drum and the bearing seat of the support frame. This dustproof flange is fitted onto the outer wall of the shaft and fixedly connected to the bearing seat, with its inner wall tightly fitted to the shaft, forming the first dustproof barrier. A labyrinth seal and a drive shaft seal are installed sequentially at the part of the shaft that passes through the support frame. The labyrinth seal consists of alternating nested stationary and moving rings, which prevent dust and moisture from entering through the labyrinthine channel. The drive shaft seal adopts an interference fit to further enhance the sealing effect of the shaft. Drive shaft seals are installed at the connection between the drive motor output shaft and the driving gear, on the outer side of the meshing transmission area between the driving gear and the driven gear, and at the connection between the driven gear and the shaft to ensure the sealing of the gear transmission area. At the same time, a polyurethane lip-shaped dustproof ring is sandwiched at the joint between the compaction ring and the lower cylinder, with the lip facing outward, effectively preventing waste particles and moisture generated during drilling from entering the interior of the layered compaction mechanism.

[0043] The driving and driven gears are installed in a gearbox that meshes with the drive motor. A dustproof lubricating oil filling port is specially designed on the side wall of the gearbox, directly connected to the internal cavity. It contains a built-in 5-10μm precision filter element to filter impurities in the lubricating oil, preventing contamination of the internal transmission components. The filling port uses a threaded sealing cap, and the mating surface between the cap and the filling port is equipped with an oil-resistant rubber sealing ring to ensure a tight seal when not in use. For routine maintenance, lubricating oil can be added simply by unscrewing the sealing cap, without disassembling the gearbox or other external components, making the operation convenient and efficient.

[0044] Multiple sealing structures effectively isolate dust, clay particles, and moisture from aquifers generated during drilling, preventing them from intruding into core transmission components such as the shaft, drive motor, drive gear, and driven gear. This reduces the risk of component wear and corrosion, making it particularly suitable for complex construction environments with high dust and humidity, such as clay and sandy soil layers. It ensures precise movement of the hydraulic cylinder of the telescopic pressure head in the layered compaction mechanism and smooth gear transmission, providing a stable hardware foundation for the PLC controller to achieve multi-parameter coupling adaptive compaction control. The dustproof lubricating oil filling port simplifies the equipment maintenance process and shortens downtime for maintenance. The design of the filter element and sealing cover ensures the cleanliness of the lubricating medium, extends the lubrication cycle and service life of transmission components such as the gearbox, reduces construction and maintenance costs, and enables the device to maintain a highly efficient and stable operating state during long-term cyclic construction. This further improves the forming quality and construction continuity of the multi-layer progressive hole protection structure.

[0045] In a preferred embodiment, the pressure sensor is installed between the hydraulic cylinder and the compaction head, and its signal output terminal is electrically connected to the signal input terminal of the data acquisition unit; the density sensor is installed on the compaction ring between adjacent telescopic pressure heads, with the probe facing the borehole wall; the temperature sensor, humidity sensor, and borehole wall pressure sensor are all installed on the compaction ring, and the signal output terminals of each sensor are electrically connected to the data acquisition unit.

[0046] In a preferred embodiment, the data input terminal of the PLC controller is electrically connected to the data output terminal of the data acquisition unit to receive sensor data before fusion; the control output terminal of the PLC controller is electrically connected to the solenoid valve of the hydraulic drive cylinder, the driver of the drive motor, the control valve of the adjustable nozzle, and the hydraulic control valve group respectively; the hydraulic control valve group is a multi-proportional valve group, which is connected to each hydraulic cylinder body through hydraulic pipelines.

[0047] In a preferred embodiment, the telescopic pressure heads are distributed at equal angles along the circumference of the compaction ring; the rear end of the cylinder body of the hydraulic cylinder is fixed to the compaction ring; and the working surface of the compaction head is an arc-shaped surface that matches the inner wall of the borehole.

[0048] The beneficial effects achieved by this invention are as follows:

[0049] First, the progressive borehole protection method based on layered compaction provided by this invention employs a construction approach that combines on-site waste collection with layered progressive forming. It obtains accurate state estimates through a multi-sensor data fusion algorithm and achieves adaptive compaction control based on a multi-parameter coupling model. This method fully utilizes borehole opening waste as protection material, reducing the workload of waste transportation and disposal, and lowering construction costs. The protection structure is formed layer by layer, with each layer being fully compacted and cured before the next layer is constructed, ensuring the overall quality of the protection structure. The combination of multi-sensor data fusion and adaptive compaction control allows the compaction process to be dynamically adjusted according to changes in the actual construction environment, improving the density and uniformity of the protection layer and enhancing the support capacity of the protection structure for the borehole wall.

[0050] Second, the method of this invention employs an extended Kalman filter algorithm to fuse data collected by density, temperature, humidity, pore wall pressure, and compressive strength sensors. By establishing a state transition model and an observation model, the algorithm predicts the current state using prior knowledge of the system, and then optimally weights and fuses the predicted and measured values ​​based on the Kalman gain. When the measurement noise of a certain sensor is high, the algorithm automatically reduces the confidence level in that measurement value, thereby effectively suppressing the transmission of noise to subsequent control stages. Through joint estimation of multi-sensor observation information, the covariance matrix dynamically adjusts the fusion weights of each sensor's data, fully leveraging the complementary advantages of redundant information from multiple sensors. This data fusion method significantly improves the estimation accuracy of state parameters such as density, temperature, humidity, and pore wall pressure, providing accurate and reliable input data for subsequent adaptive compaction control and avoiding compressive strength calculation deviations caused by sensor noise.

[0051] Third, the method of this invention employs a multi-parameter coupled adaptive compaction control strategy. Temperature correction coefficients, humidity correction coefficients, and borehole wall pressure correction coefficients are calculated based on the fused estimates of temperature, humidity, and borehole wall pressure. These are then combined with the ratio of the current density estimate to the target density to determine the target compaction strength. The temperature correction coefficient compensates for the effects of temperature changes on the curing agent reaction rate and the mechanical properties of the borehole protection material. It increases the compaction strength at low temperatures to overcome the reduction in material plasticity and decreases it at high temperatures to prevent premature hardening. The humidity correction coefficient performs nonlinear correction based on the deviation between the current humidity and the optimal humidity, maintaining a moderate compaction strength under optimal humidity conditions and adjusting accordingly when humidity deviates from the optimal value. The borehole wall pressure correction coefficient reflects changes in formation constraints. When the borehole wall pressure is high, the compaction strength is appropriately increased to overcome formation reaction forces; when the borehole wall pressure is low, the compaction strength is appropriately decreased to avoid over-compaction. This allows the compaction strength to adapt to the complex changes in the actual construction environment, achieving ideal compaction results under different temperature, humidity, and formation conditions, thus improving the stability and consistency of the borehole protection layer's density.

[0052] Fourth, this invention employs a layered, progressive construction method. After each layer of protective material is compacted, the device moves upward a certain distance, equal to the thickness of a single layer minus the interlayer overlap, resulting in a partial vertical overlap between adjacent layers. This interlayer overlap design allows the lower part of the upper layer to interlock with the upper part of the lower layer during compaction, forming a mechanical interlocking structure that enhances the bond strength between adjacent layers and prevents delamination or peeling. The thickness of each protective material layer is controlled within a small range, ensuring that each layer is fully compacted and avoiding insufficient internal compaction issues common in one-time thick-layer molding. This layer-by-layer accumulation construction method ensures that each layer undergoes independent waste distribution, curing agent spraying, data fusion, and adaptive compaction processes, allowing for independent control and guarantee of the construction quality of each layer. The resulting multi-layer protective structure exhibits uniform density, strong interlayer bonding, and high overall strength.

[0053] Fifth, the progressive hole-protecting device based on layered compaction provided by this invention integrates waste collection, distribution, and curing agent spraying functions using a hollow rotating drum structure. A scraper at the bottom of the lower drum scrapes waste into the drum as it rotates. Under centrifugal force, the waste is evenly discharged from the waste outlet on the side wall. An adjustable nozzle on the inner wall of the upper drum sprays curing agent downwards to mix with the waste, achieving integrated operation of waste collection and curing agent addition. In the layered compaction mechanism, multiple telescopic pressure heads are evenly distributed along the circumference of the compaction ring. Each pressure head's independent hydraulic cylinder is controlled by a hydraulic control valve group. Combined with real-time feedback from pressure force sensors, synchronous control and independent adjustment of the pressure force of each pressure head are achieved, ensuring the uniformity of hole-protecting layer compaction in the circumferential direction. In the sensor system, a density sensor, temperature sensor, humidity sensor, and hole wall pressure sensor are installed on the compaction ring, while pressure force sensors are installed on each telescopic pressure head, enabling comprehensive monitoring of key parameters during the construction process. The extended Kalman filter algorithm module and multi-parameter coupled pressure calculation module built into the PLC controller in the control system realize the integration of data fusion and adaptive control functions. The lifting and adjusting mechanism drives the lifting slider to move along the guide rail through the hydraulic drive cylinder, realizing the precise positioning and layered upward movement of the device, and ensuring the positional accuracy of layered construction. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the overall structure of the progressive hole protection device based on layered compaction;

[0055] Figure 2 This is a schematic diagram of the compaction ring structure;

[0056] Figure 3 This is a comparison chart of the density state estimation errors of Example 1 and Comparative Example 1;

[0057] Figure 4This is a comparison chart of Example 1 and Comparative Example 1 regarding the RMSE of each parameter; Figure 4 Subplot (a) shows the RMSE comparison for density; subplot (b) shows the RMSE comparison for temperature; subplot (c) shows the RMSE comparison for humidity; subplot (d) shows the RMSE comparison for pore wall pressure.

[0058] Figure 5 This is a comparison diagram of the density distribution of the protective layer between Example 1 and Comparative Example 2;

[0059] Figure 6 This is a comparison graph of the coefficient of variation of density between Examples 1 to 3 and Comparative Example 2;

[0060] Figure 7 This is a graph showing the pressure force tracking effect of Example 1;

[0061] Figure 8 This is a comparison diagram of the 28-day compressive strength distribution of the protective layer between Example 1 and Comparative Example 2;

[0062] Figure 9 This is a graph showing the convergence process of the density estimate during EKF filtering in Example 1;

[0063] Figure 10 This is a comparison graph of the compaction effect of Example 1 and Comparative Example 2 under different temperature conditions;

[0064] Figure 11 This is a sectional view of the driven gear mounting structure;

[0065] Figure 12 This is a control principle diagram of the progressive hole protection device based on layered compaction of the present invention.

[0066] Numbering on the map:

[0067] 1. Back plate; 2. Guide rail; 4. Hydraulic drive cylinder; 5. Lifting slider; 6. Support frame; 7. Dustproof lubricating oil filling port; 8. Labyrinth seal; 9. Dustproof flange; 11. Drill rod; 12. Driven gear; 13. Drive motor; 14. Drive gear; 15. Waste outlet; 16. Nozzle mounting chamber; 17. Adjustable nozzle; 18. Scraper; 19. Drive shaft seal; 20. Sealing ring; 22. Temperature sensor; 28. Compaction ring; 29. ​​Telescopic pressure head; 30. Compaction force sensor; 37. Density sensor; 38. Humidity sensor; 39. Hole wall pressure sensor; 50. PLC controller; 52. Data acquisition unit; 53. Hydraulic control valve group; 101. Upper cylinder; 102. Lower cylinder; 291. Hydraulic cylinder body; 292. Compaction head. Detailed Implementation

[0068] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0069] Reference Figures 1-2 The progressive hole protection device based on layered compaction provided by this invention includes a lifting and adjusting mechanism, hole protection forming components, a layered compaction mechanism, a sensor system, and a control system. The lifting and adjusting mechanism is used to realize the vertical lifting and lowering movement of the entire hole protection device. A back plate 1 is fixedly installed on the frame of the drilling rig, serving as the mounting base for the entire hole protection device. A guide rail 2 is fixed vertically to the surface of the back plate 1, providing guiding constraints for the lifting and lowering movement. The lifting slider 5 is slidably connected to the guide rail 2 via a groove structure, and under the constraint of the guide rail 2, it can only move up and down vertically. The cylinder body of the hydraulic drive cylinder 4 is fixedly installed on the back plate 1, and its piston rod is rigidly connected to the lifting slider 5. When the piston rod of the hydraulic drive cylinder 4 extends or retracts, the lifting slider 5 moves up and down along the guide rail 2, thereby driving all the hole protection forming components installed on the lifting slider 5 to lift and lower synchronously.

[0070] The hole-protecting forming assembly is used to collect drilling waste, spray curing agent, and form a hole-protecting layer. The support frame 6 is fixedly mounted on the lifting slider 5, serving as the load-bearing structure for the hole-protecting forming assembly. The hollow rotating cylinder is rotatably connected to the support frame 6 via a rotating shaft at its top. The rotating shaft is mounted on the top of the support frame 6 via a bearing seat, allowing the hollow rotating cylinder to rotate freely around the shaft. The hollow rotating cylinder is a single structure formed by the fixed connection of the upper cylinder 101 and the lower cylinder 102, with a through-hole in the center for the drill rod 11 to pass through. The drive motor 13 is fixedly mounted on the support frame 6, and a drive gear 14 is fixedly mounted on its output shaft. A driven gear 12 is fixedly mounted on the rotating shaft. The drive gear 14 and the driven gear 12 mesh with each other, and when the drive motor 13 operates, it drives the hollow rotating cylinder to rotate around the rotating shaft through gear transmission.

[0071] The upper cylinder 101 is a hollow cylindrical structure with multiple nozzle mounting chambers 16 evenly distributed along the circumference of its inner wall. Each nozzle mounting chamber 16 contains an adjustable nozzle 17, which sprays downwards to spray curing agent towards the lower cylinder 102. The lower cylinder 102 is also a hollow cylindrical structure with multiple waste outlets 15 evenly distributed along the circumference of its side wall. The waste outlets 15 extend axially along the lower cylinder 102 to form strip-shaped openings, allowing waste in the hollow rotating cylinder cavity to be thrown out under centrifugal force. Multiple scrapers 18 are evenly fixed along the circumference of the bottom side wall of the lower cylinder 102. The scrapers 18 extend radially outwards and are slightly inclined downwards. When the hollow rotating cylinder rotates, the scrapers 18 rotate accordingly, scraping the waste accumulated around the drill hole into the hollow rotating cylinder cavity.

[0072] The layered compaction mechanism is used to radially compact the formed borehole layer. A compaction ring 28 is fixedly installed at the bottom of the lower cylinder 102, arranged in a ring structure around the outer periphery of the hollow rotating cylinder. Multiple telescopic pressure heads 29 are evenly distributed at equal angles along the circumference of the compaction ring 28. Each telescopic pressure head 29 includes a hydraulic cylinder body 291 and a compaction head 292. The hydraulic cylinder body 291 is fixedly installed radially on the compaction ring 28, with its rear end rigidly connected to the compaction ring 28. The compaction head 292 is installed at the front end of the piston rod of the hydraulic cylinder body 291, and its working surface is designed as an arc-shaped surface matching the curvature of the borehole inner wall, ensuring that the compaction head 292 makes close contact with the surface of the borehole layer during compaction, guaranteeing uniform transmission of pressure. When the piston rod of the hydraulic cylinder body 291 extends, the compaction head 292 moves radially outward to apply radial pressure to the borehole layer.

[0073] The sensor system is used to collect various parameters during the borehole protection process in real time. A pressure sensor 30 is installed on each telescopic pressure head 29, specifically at the connection point between the hydraulic cylinder body 291 and the compaction head 292, to detect the pressure applied by the compaction head 292 and output the detection signal to the data acquisition unit 52. A density sensor 37 is installed on the compaction ring 28, located in the gap between two adjacent telescopic pressure heads 29, with its probe facing the borehole wall, to detect the density of the borehole protection layer. Temperature sensor 22 and humidity sensor 38 are both installed on the compaction ring 28 to detect the ambient temperature and humidity in the borehole protection layer area, respectively. A borehole wall pressure sensor 39 is also installed on the compaction ring 28 to detect the reaction force of the borehole protection layer on the borehole wall. The signal output terminals of each sensor are electrically connected to the data acquisition unit 52.

[0074] The control system coordinates and controls the automated operation of the entire borehole protection process. The data acquisition unit 52 is electrically connected to the pressure sensor 30, density sensor 37, temperature sensor 22, humidity sensor 38, and borehole wall pressure sensor 39, and is used to acquire the detection signals from each sensor and perform analog-to-digital conversion. The data input terminal of the PLC controller 50 is electrically connected to the data output terminal of the data acquisition unit 52, receiving the sensor data processed by the data acquisition unit 52. The control output terminal of the PLC controller 50 is electrically connected to the solenoid valve of the hydraulic drive cylinder 4, the driver of the drive motor 13, the control valve of the adjustable nozzle 17, and the hydraulic control valve group 53, respectively. The PLC controller 50 has a built-in extended Kalman filter algorithm module, used to fuse data from multiple sensors, reducing the impact of measurement noise and improving the accuracy of state estimation. The PLC controller 50 also has a built-in multi-parameter coupled pressure calculation module, used to calculate the target pressure considering the influence of various environmental factors based on the fused state estimation value. The hydraulic control valve group 53 is a multi-proportional valve group, connected to each hydraulic cylinder 291 via hydraulic lines, to achieve independent and precise control of each telescopic pressure head 29.

[0075] A dustproof flange 9 is provided at the joint between the shaft of the hollow rotating drum and the bearing seat of the support frame 6. The dustproof flange 9 is sleeved on the outer wall of the shaft and fixedly connected to the bearing seat. The inner wall is tightly fitted with the shaft to form the first dustproof barrier. A labyrinth seal 8 and a drive shaft seal 19 are sequentially installed at the part of the shaft that passes through the support frame 6. The labyrinth seal 8 is composed of alternating nested stationary rings and moving rings. It blocks dust and moisture from entering through the labyrinth channel. The drive shaft seal 19 adopts an interference fit to further enhance the sealing effect of the shaft. Drive shaft seals 19 are installed at the connection between the output shaft of the drive motor 13 and the drive gear 14, the outer side of the meshing transmission area between the drive gear 14 and the driven gear 12, and the connection between the driven gear 12 and the shaft to ensure the sealing of the gear transmission area. At the same time, a polyurethane lip-shaped dustproof ring is sandwiched at the joint between the compaction ring 28 and the lower cylinder 102. The lip faces outward to effectively prevent waste particles and moisture generated during drilling from entering the interior of the layered compaction mechanism.

[0076] The driving gear 14 and driven gear 12 are installed in a gearbox that meshes with the drive motor 13. A dustproof lubricating oil filling port 7 is specially provided on the side wall of the gearbox. This port is directly connected to the internal cavity of the gearbox and contains a built-in 5-10μm precision filter element to filter impurities in the lubricating oil, preventing contamination of the internal transmission components. The filling port uses a threaded sealing cap, and the mating surface between the cap and the filling port is equipped with an oil-resistant rubber sealing ring 20 to ensure sealing when not in use. For routine maintenance, lubricating oil can be added simply by unscrewing the sealing cap without disassembling the gearbox or other external components, making the operation convenient and efficient.

[0077] Multiple sealing structures effectively isolate dust, clay particles, and moisture from the aquifer generated during drilling, preventing them from intruding into core transmission components such as the rotating shaft, drive motor 13, drive gear 14, and driven gear 12. This reduces the risk of component wear and corrosion, making it particularly suitable for complex construction environments with high dust and humidity, such as clay and sandy soil layers. It ensures precise operation of the hydraulic cylinder 291 of the telescopic pressure head 29 in the layered compaction mechanism and smooth gear transmission, providing a stable hardware foundation for the PLC controller 50 to achieve multi-parameter coupling adaptive compaction control. The dustproof lubricating oil filling port 7 simplifies the equipment maintenance process and shortens downtime for maintenance. The design of the filter element and sealing cover ensures the cleanliness of the lubricating medium, extends the lubrication cycle and service life of transmission components such as the gearbox, and reduces construction and maintenance costs. This allows the device to maintain a highly efficient and stable operating state during long-term cyclic construction, further improving the forming quality and construction continuity of the multi-layer progressive hole protection structure.

[0078] Reference Figure 11 The progressive hole protection method based on layered compaction provided by this invention is implemented using the aforementioned apparatus and includes the following steps S1 to S7. The implementation process of this method is described in detail below with reference to the claims.

[0079] Step S1: Drilling and Equipment Positioning Stage; First, control the drilling rig to perform drilling operations, setting the single drilling depth according to construction parameters such as stratum type and borehole diameter. Drilling stops after the rig reaches the preset depth. The setting of the preset depth needs to comprehensively consider factors such as stratum stability, borehole diameter, borehole protection device size, and construction efficiency. For clay strata, due to their tendency to expand and soften when exposed to water, the single drilling depth should be appropriately reduced to allow for timely borehole protection treatment; for rock strata, where stratum stability is better, the single drilling depth can be appropriately increased to improve construction efficiency. After the drilling rig reaches the preset depth and stops, the hydraulic drive cylinder is activated. The cylinder body of the hydraulic drive cylinder is fixed to the back plate, and the piston rod is connected to the lifting slider. By controlling the extension of the piston rod of the hydraulic drive cylinder, the lifting slider moves downward along the guide rail, thereby driving the entire borehole protection device fixed on the lifting slider to move downward until the hollow rotary cylinder moves to the borehole opening for positioning. During the positioning process, it is necessary to ensure that the scraper at the bottom of the hollow rotary drum is located in the waste accumulation area at the borehole opening, and that the scraper is in good contact with the waste, so as to create conditions for subsequent waste collection.

[0080] Step S2: Waste Collection and Discharge Stage; After the device is positioned, the drive motor is started. A drive gear is mounted on the output shaft of the drive motor, meshing with a driven gear fixed to the top shaft of the hollow rotating drum. The rotational motion of the drive motor is transmitted to the hollow rotating drum via gear transmission, causing the drum to rotate around its axis. The rotational speed of the hollow rotating drum needs to be set according to factors such as the nature of the waste, the borehole diameter, and the desired thickness of the protective material layer. Too low a rotational speed will result in insufficient waste collection efficiency, with less waste discharged per unit time, extending construction time; too high a rotational speed may lead to excessive centrifugal force on the waste during discharge, causing the waste to be thrown out too quickly, making it difficult to distribute evenly around the borehole wall, and potentially causing material waste and environmental pollution. Through extensive experimental research and field application verification, the preferred rotational speed range for the hollow rotating drum is 20 rpm to 40 rpm. Within this speed range, the waste collection and discharge process is smooth. The discharged waste is thrown outwards at a moderate speed under centrifugal force, naturally settling and evenly distributing around the borehole wall. As the hollow drum rotates, the scraper fixed to the bottom of the lower drum rotates accordingly, extending radially outwards. Its outer edge scrapes the waste accumulation area at the borehole opening. During rotation, the scraper continuously contacts the accumulated waste, scraping it into the inner cavity of the hollow drum. The waste rotates with the drum within the hollow drum cavity, subjected to centrifugal force. The magnitude of the centrifugal force is proportional to the rotational angular velocity of the drum and the distance from the waste to the drum's axis. When the centrifugal force is sufficiently large, the waste overcomes the friction with the inner wall of the drum and is thrown out from the waste outlet located on the side wall of the lower drum. The waste outlet is distributed along the circumference of the lower drum and extends axially to form a strip-shaped opening. This design allows waste to be discharged simultaneously from multiple directions, ensuring uniform discharge. After being discharged from the waste outlet, the waste material moves radially outward under centrifugal force, falling around the borehole wall to form a single layer of borehole protection material. The thickness of this single layer is affected by various factors, including the drum rotation speed, the scraping efficiency of the scraper, the properties of the waste material, and the amount of waste material accumulated. By reasonably controlling these parameters, the thickness of the single layer can be controlled within a desired range. The preferred thickness range for the single layer is 20mm to 50mm. Within this range, the single layer provides sufficient support without causing insufficient compaction due to excessive thickness.

[0081] Step S3: Curing Agent Spraying Stage; Simultaneously with the discharge of waste material forming a single layer of protective material, curing agent needs to be sprayed into the waste material to ensure thorough mixing and curing, forming a cured protective layer with a certain strength. The curing agent is sprayed downwards through adjustable nozzles installed in the nozzle mounting chamber on the inner wall of the upper cylinder. These adjustable nozzles are distributed along the circumference of the upper cylinder, spraying downwards towards the area where the waste material is discharged. Precise control of the curing agent spraying amount is crucial for the protective effect. Insufficient curing agent will result in incomplete curing of the waste material and insufficient strength of the protective layer; excessive curing agent will lead to material waste and may also affect the air permeability and drainage of the protective material, even causing cracking of the protective layer.

[0082] Hardener spray volume The calculation is based on the volume of a single layer of protective material and the volume ratio of curing agent to waste. The calculation formula is: ;in: This refers to the amount of hardener sprayed, expressed in liters (L). The outer diameter of the borehole protection layer is expressed in meters (m), and refers to the distance from the outer surface of the borehole protection layer to the borehole axis. The inner diameter of the borehole protection layer is measured in meters (m). It refers to the distance from the inner surface of the borehole protection layer to the borehole axis and is usually equal to the borehole radius. The thickness of a single layer of protective material is expressed in meters (m). The volume ratio of curing agent to waste material is a dimensionless number, representing the ratio of the volume of curing agent to the total volume of the pore-protecting material. In this formula... The calculation involves the cross-sectional area of ​​the protective layer, multiplied by the thickness of a single layer. This yields the volume of a single-layer protective material, which is then multiplied by the volume ratio. This yields the desired volume of curing agent. The volume ratio of curing agent to waste material is also considered. The required volume ratio needs to be determined based on factors such as the nature of the waste material, the desired strength of the protective layer, and the performance of the curing agent. The preferred volume ratio range is 0.25 to 0.40. Within this range, the amount of curing agent used ensures that the waste material is fully cured to achieve the expected strength without excessive material waste. In actual construction, the borehole diameter is first measured to determine the inner diameter of the protective layer. Determine the outer diameter of the protective layer according to design requirements. Combined with the single-layer thickness set in step S2 above and the selected curing agent to waste volume ratio Substituting into the above formula, the required amount of curing agent to be sprayed for a single layer of protective material is calculated. Then control the opening of the adjustable nozzle and the spray time, according to the calculated spray volume. Precise spraying is performed. The adjustable nozzle is controlled by an electronically controlled valve or a proportional valve. The PLC controller sends a control signal to the control valve of the adjustable nozzle based on the calculated spray volume. The control valve adjusts the nozzle opening according to the signal to achieve precise flow control. The spraying process is synchronized with the waste discharge process. The hardener is sprayed onto the discharged waste and mixes with it during the waste's movement. This mixing process utilizes the movement characteristics of the waste under centrifugal force, ensuring sufficient contact between the hardener and the waste. In addition, the rotation of the hollow drum also helps to mix the hardener with the waste. The disturbance generated by the drum's rotation makes the hardener more evenly dispersed in the waste. After mixing with the waste, the hardener is deposited around the borehole wall and begins to undergo a curing reaction, gradually forming a cured protective layer with a certain strength and density, creating conditions for subsequent compaction operations.

[0083] Step S4: Multi-sensor data fusion stage; This step uses the extended Kalman filter algorithm to fuse the detection data from multiple sensors, outputting high-precision state estimates to provide reliable input parameters for subsequent adaptive compaction control. The drilling and borehole protection process is a complex dynamic process. State parameters such as the density of the borehole protection layer, the temperature and humidity of the surrounding environment, and the pressure on the borehole wall change continuously with the construction progress. Accurate acquisition of these parameters is crucial for achieving precise compaction control. Sensors are inevitably subject to various noise interferences in the actual working environment, including measurement noise from the sensors themselves, environmental interference noise, and interference noise caused by mechanical vibrations during construction, resulting in significant fluctuations and errors in the original measurement data. If the original sensor measurements are directly used as the control basis, the control parameters will frequently change with the measurement noise, affecting the stability and compaction quality of the compaction process. The extended Kalman filter algorithm is an online recursive filtering algorithm that can optimally estimate noisy measurement data, fully utilizing the complementarity and redundancy of information from multiple sensors to obtain high-precision state estimates.

[0084] Sub-step S41: Data acquisition; The data acquisition unit collects the raw measurement values ​​of each sensor at a fixed sampling period to form an observation vector. The data acquisition unit is electrically connected to a density sensor, temperature sensor, humidity sensor, orifice wall pressure sensor, and pressure sensor. It converts the analog signals output by the sensors into digital signals via an analog-to-digital converter, and then displays the data from each sensor at the current sampling time. The measured values ​​are combined into an observation vector. The selection of the sampling period needs to comprehensively consider the dynamic characteristics of the system and the limitations of computing resources. An excessively long sampling period will lead to untimely tracking of system state changes, while an excessively short sampling period will increase the computational burden. The preferred sampling period range is 50ms to 200ms, which allows for timely capture of system state changes without placing excessive computational pressure on the PLC controller. Sub-step S42: State prediction; The PLC controller uses the posterior estimate of the state from the previous period... Obtain the prior state estimate for the current period The Extended Kalman Filter (EKF) algorithm consists of two phases: prediction and update. The prediction phase utilizes the system's state transition model to calculate the predicted state value for the current moment based on the optimal estimate from the previous moment. During borehole construction, the system state changes relatively slowly; it can be assumed that the state remains constant or changes according to a certain pattern within a short period. Therefore, the prior state estimate... You can directly take the posterior estimate of the state from the previous period. Alternatively, predictions can be made based on the system's dynamic model. For more accurate predictions, a mathematical model can be established to show the changes in the density, temperature, humidity, and borehole wall pressure over time, and the current state value can be predicted based on the model. Sub-step S43: Calculate the prior covariance matrix; the calculation formula is: ;in: for The prior covariance matrix at time t; for The posterior covariance matrix at time t; Let be the process noise covariance matrix.

[0085] The covariance matrix describes the uncertainty of state estimation. The diagonal elements of the matrix represent the variance of the estimation errors for each state variable, while the off-diagonal elements represent the covariance among the estimation errors of different state variables. (Prior covariance matrix) From the posterior covariance matrix of the previous time step Add process noise covariance matrix The process noise covariance matrix is ​​obtained. This reflects the uncertainties in the system state transition process, including the effects of model errors and system noise. Process noise covariance matrix. The settings need to be adjusted based on the characteristics of the system and actual testing. A larger value indicates a lower level of trust in the system model, and the filter will rely more on the measured values; A smaller value indicates a higher level of trust in the system model, meaning the filter will rely more heavily on the predicted values. Sub-step S44: Calculate the Kalman gain matrix; the formula is:

[0086] ;in: for Kalman gain matrix at time step; The prior covariance matrix; The observation matrix; for The transpose of the matrix; To observe the noise covariance matrix; Inverting a matrix. Kalman gain matrix. This is a core parameter of the Extended Kalman Filter (EKF) algorithm, determining the fusion weights of predicted and measured values ​​during state updates. The calculation of the gain matrix involves the prior covariance matrix. Observation matrix and observation noise covariance matrix The observation matrix This describes the relationship between state variables and observed variables, including the observation noise covariance matrix. This reflects the uncertainty in sensor measurements. When the observation noise is large, that is... When it is large, the Kalman gain When the observation noise is relatively small, the filter trusts the predicted values ​​more and the measured values ​​less, thus suppressing the impact of measurement noise on the estimation results; when the observation noise is relatively small... When it is small, the Kalman gain The larger the noise level, the more the filter trusts the measured values, making full use of the accurate information provided by the sensor. This dynamic adjustment mechanism makes the extended Kalman filter algorithm adaptive, achieving optimal estimation results under different noise conditions.

[0087] Sub-step S45: State update; the calculation formula is: ;in: for The posterior estimate of the state at time 1; These are prior state estimates; The Kalman gain matrix; Let be the observation vector. This formula represents the posterior estimate of the state. From the state prior estimate Adding a correction term yields the result, which is the Kalman gain matrix. With the new vector The product of the new information vectors, where the new information vectors are... Indicates the actual measured value Compared with the predicted value The innovation vector reflects the difference between the prediction model and the actual situation. By weighting the innovation vector with the Kalman gain matrix, this difference information is incorporated into the state estimate, thus correcting the predicted value. The output fused state estimate includes the density estimate. Temperature estimate Humidity estimates and estimated borehole wall pressure These estimates combine measurement information from multiple sensors, eliminating most of the influence of measurement noise, and are more accurate and reliable than the original measurements from a single sensor. Sub-step S46: Update the posterior covariance matrix; the calculation formula is:

[0088] ;in: for The posterior covariance matrix at time t; It is the identity matrix; The Kalman gain matrix; The observation matrix; Let be the prior covariance matrix. Let be the posterior covariance matrix. This describes the estimation uncertainty after the state update, compared to the prior covariance matrix. The posterior covariance matrix typically decreases, reflecting improved estimation accuracy through the fusion of measurement information. The updated posterior covariance matrix. This information will be used as input for calculating the prior covariance matrix in the next filtering cycle, thus forming a recursive filtering process. After completing one filtering cycle, the algorithm returns to substep S41 to enter the next cycle of data acquisition and fusion processing, continuously outputting high-precision state estimates.

[0089] Through the multi-sensor data fusion process described above, the Extended Kalman Filter (EKF) algorithm utilizes redundant and complementary information from multiple sensors, eliminating measurement noise through optimal weighted fusion to obtain a more accurate state estimate than that of a single sensor. The compaction sensor provides direct measurement of the borehole layer compaction, temperature and humidity sensors provide environmental condition information, borehole wall pressure sensors reflect the formation constraint state, and pressure sensors monitor the forces acting during compaction. These sensors monitor key parameters of the borehole construction process from different perspectives. When a sensor experiences a significant error due to malfunction or interference, the EKF algorithm can compensate using information from other sensors, ensuring the reliability of the estimation results. Furthermore, the algorithm's recursive nature enables it to learn online; as the filtering cycle increases, the algorithm's understanding of system characteristics continuously improves, leading to a sustained increase in estimation accuracy. Even if the initial state estimate deviates significantly from the true value during the initial filtering phase, the algorithm can gradually converge to the true value through continuous correction. This characteristic is crucial for addressing initial condition deviations and sudden disturbances during construction.

[0090] Step S5: Multi-parameter Coupled Adaptive Compaction Stage; This step, based on the fused state estimate output from Step S4, calculates the target compaction force considering the coupled influence of multiple environmental factors. Then, closed-loop control is used to make the actual compaction force track the target compaction force, achieving adaptive compaction of the pore layer. The compaction quality of the pore layer is affected by various factors, including the density of the pore material itself, ambient temperature, ambient humidity, and pore wall pressure. These factors are coupled and work together in the compaction process. Temperature affects the curing reaction rate of the curing agent and the mechanical properties of the pore material. At lower temperatures, the curing reaction is slower, the pore material has poor plasticity, and a greater compaction force is required to achieve the desired density. At higher temperatures, the curing reaction is faster, the material is prone to premature hardening, and excessive compaction force may cause deformation or cracking of the pore layer. Humidity affects the moisture content and compactability of the pore material. Appropriate humidity is conducive to the slippage and rearrangement between material particles, improving the compaction effect, but excessively high or low humidity will reduce the compactability of the material. Borehole wall pressure reflects the constraint of the formation on the borehole retaining layer. Higher borehole wall pressure indicates stronger formation constraint, requiring an appropriate increase in compaction force to overcome this constraint. Conversely, lower borehole wall pressure indicates weaker formation constraint, and excessive compaction force may cause the retaining layer to intrude into the borehole wall. Traditional fixed compaction force methods cannot adapt to changes in these environmental factors, resulting in significant differences in compaction effects under different construction conditions. This invention establishes a multi-parameter coupled compaction force calculation model, dynamically adjusting the target compaction force based on real-time monitored environmental parameters to achieve adaptive compaction control.

[0091] Sub-step S51: Receive the merged state estimate; the PLC controller receives the merged state estimate output in step S4, including the density estimate. Temperature estimate Humidity estimates and estimated borehole wall pressure These state estimates, processed by the extended Kalman filter algorithm, have eliminated most of the measurement noise, making them more accurate and reliable than the original sensor measurements, and providing high-quality input data for subsequent pressure force calculations.

[0092] Sub-step S52: Calculate the temperature correction factor; the calculation formula is: ;in: This is the temperature correction factor, which is a dimensionless number. The temperature estimate after fusion is in degrees Celsius (°C). The reference temperature is expressed in degrees Celsius (°C); 0.02 is the temperature influence coefficient, reflecting the degree of influence of temperature changes on pressure demand; 10 is the temperature normalization coefficient, expressed in degrees Celsius (°C), used to convert temperature differences into dimensionless correction quantities. This formula establishes a linear relationship between the temperature correction coefficient and the temperature deviation. When the actual temperature... equal to reference temperature At that time, temperature correction factor A value of 1 indicates that no temperature correction is needed; when the actual temperature... Below reference temperature At that time, temperature correction factor A value less than 1 will increase the target compaction force in subsequent calculations to compensate for the adverse effects of reduced material plasticity on compaction under low-temperature conditions; when the actual temperature... Higher than reference temperature At that time, temperature correction factor A value greater than 1 will reduce the target compressive strength, preventing excessive compressive strength under high-temperature conditions from causing deformation or cracking of the protective layer. Reference temperature. The selection of the temperature influence coefficient needs to be determined based on the performance characteristics of the curing agent and the mechanical properties of the pore-forming material. Typically, the temperature at which the pore-forming material achieves optimal compaction under normal construction conditions is chosen as the reference temperature, with a common range of 15℃ to 25℃. The temperature influence coefficient of 0.02 is based on extensive experimental data and field application experience, reflecting the actual impact of temperature changes on the required compaction strength. This coefficient value can be fine-tuned according to the specific material system and curing agent type to achieve the best adaptive control effect.

[0093] Sub-step S53: Calculate the humidity correction factor; the calculation formula is: in: This is the humidity correction factor, which is a dimensionless number. The combined humidity estimate is in percentage (%). The optimal humidity is expressed as a percentage (%); 0.15 is the humidity influence coefficient, reflecting the degree of influence of humidity deviation on pressure demand. This formula establishes a quadratic function relationship between the humidity correction coefficient and the humidity deviation. When the actual humidity... equal to optimal humidity Humidity correction factor A value of 1 indicates that no humidity correction is needed; when the actual humidity... Deviation from optimal humidity At any time, regardless of whether the humidity is too high or too low, the humidity correction factor All values ​​will be less than 1, increasing the target compaction force. This design is based on experimental research results on the compaction characteristics of the pore-forming material. The material's compactability is best when the humidity is near its optimal value. Deviating from the optimal value, whether too high or too low, will reduce the material's compactability, requiring increased compaction force to achieve the same density. Optimal humidity. Determining the optimal compaction density requires a series of compaction experiments conducted under varying humidity conditions. These experiments measure the required compaction force to achieve the target density, identifying the humidity value that minimizes this force as the optimal humidity. Different types of waste materials and formation materials have different optimal humidity levels. For clay waste, the optimal humidity is typically between 10% and 20%, while for sandy waste it is typically between 5% and 15%. The humidity influence coefficient of 0.15 is also based on experimental data, reflecting the severity of the impact of humidity deviation on compaction. A larger coefficient indicates a more significant impact of humidity deviation on compaction, requiring substantial adjustments to the compaction force.

[0094] Sub-step S54: Calculate the hole wall pressure correction factor; the calculation formula is: ;in: This is the correction factor for the borehole wall pressure, which is a dimensionless number. This is for calculating the minimum value; This is for calculating the maximum value. The value is the estimated pressure of the fused pore wall, in kilopascals (kPa). The reference orifice wall pressure is expressed in kilopascals (kPa); 0.1 is the orifice wall pressure influence coefficient, reflecting the degree to which changes in orifice wall pressure affect the required pressure; 0.8 is the lower limit of the correction coefficient to prevent insufficient pressure due to an excessively small correction coefficient; 1.2 is the upper limit of the correction coefficient to prevent excessive pressure due to an excessively large correction coefficient. This formula first calculates the relative value of the orifice wall pressure deviation. Then multiply by the influence coefficient 0.1 to get the basic correction amount, add 1 to get the preliminary correction coefficient, and finally... and The calculation limits the correction factor to the range of 0.8 to 1.2. This applies when the actual borehole wall pressure... Equal to reference borehole wall pressure At that time, the correction factor for the borehole wall pressure A value of 1 indicates that no orifice wall pressure correction is needed; when the actual orifice wall pressure... Greater than the reference borehole wall pressure At that time, the correction factor for the borehole wall pressure A value greater than 1 but not exceeding 1.2 allows for an appropriate increase in the target pressure to overcome strong formation constraints; when the actual borehole wall pressure Less than the reference borehole wall pressure At that time, the correction factor for the borehole wall pressure A value less than 1 but not less than 0.8 is used to appropriately reduce the target compressive strength to prevent excessive intrusion of the protective layer into the borehole wall. The upper and lower limits of the correction coefficient are set based on safety considerations, avoiding excessively large or small correction coefficients that would cause the compressive strength to deviate from a reasonable range. The upper limit of 1.2 means that even under high borehole wall pressure, the increase in compressive strength will not exceed 20%, and the lower limit of 0.8 means that even under low borehole wall pressure, the decrease in compressive strength will not exceed 20%. These limits ensure the safety and controllability of the compaction process. Reference borehole wall pressure. The choice of reference pressure needs to be determined based on the formation type and drilling depth. For shallow boreholes, the borehole wall pressure is usually low, so a lower value can be selected. For deep boreholes, the borehole wall pressure increases with depth, so the reference pressure should be increased accordingly.

[0095] Sub-step S55: Calculate the target compressive strength; the calculation formula is: in: The force exerted to achieve the target is expressed in kilonewtons (kN). The reference compressive strength is expressed in kilonewtons (kN). Target density is a dimensionless number representing the desired density value. The current density estimate after fusion is a dimensionless number. This is a temperature correction factor; This is the humidity correction factor; This is the correction coefficient for pore wall pressure. This formula comprehensively considers the influence of four key factors—density, temperature, humidity, and pore wall pressure—on the required pressure, and obtains the optimal target pressure through multi-parameter coupling calculation. The basic structure of the formula is the baseline pressure. Multiply by density correction factor Then multiply by three environmental correction factors. Among them, the density correction factor... This represents the ratio of the current density to the target density. Below target density When the ratio is greater than 1, the target compressive strength increases; when the current density... Approaching target density At this point, the ratio approaches 1, and the target pressure approaches the reference value. This design achieves closed-loop control based on density feedback. Reference pressure This refers to the compressive strength required to achieve the target density under reference environmental conditions. Its value needs to be determined experimentally. Compaction tests are conducted under reference temperature, optimal humidity, and reference borehole wall pressure conditions, and the compressive strength required to achieve the target density is measured as a baseline value. Different borehole protection materials and compaction equipment have different baseline compressive strengths. Clay materials typically require higher compressive strength, sandy materials require relatively lower compressive strength, and rock debris materials require varying compressive strengths depending on particle size and gradation. Target density The strength requirement is determined based on the strength requirements of the hole protection structure, typically within the range of 0.85 to 0.95. Higher density results in greater strength of the hole protection layer, but also requires more energy for compaction. The specific strength needs to be determined comprehensively based on the application scenario and economic considerations.

[0096] Sub-step S56: Pressure control; the hydraulic control valve group controls the pressure according to the target pressure. The system controls the synchronous movement of each hydraulic cylinder, driving the compaction head to extend radially and apply pressure to the protective borehole layer. Each hydraulic cylinder of the telescopic pressure head is connected to a hydraulic control valve assembly via hydraulic lines. This assembly is a multi-port proportional valve assembly, allowing independent control of the output pressure of each hydraulic cylinder. The PLC controller sends control signals to the hydraulic control valve assembly, and these signals are adjusted according to the target pressure. Calculations show that the hydraulic control valve assembly adjusts the valve core opening of each proportional valve according to the control signal, thereby controlling the oil supply pressure and flow rate of each hydraulic cylinder, causing the hydraulic cylinder to generate corresponding thrust to drive the compaction head. A pressure sensor is installed between the hydraulic cylinder and the compaction head to detect the actual pressure in real time. The PLC controller receives the detection signal from the pressure sensor and converts the actual pressure... With the target pressure strength The pressure deviation is compared and calculated. Based on the deviation signal, the output of the hydraulic control valve group is adjusted using a proportional-integral-derivative (PID) control algorithm or other advanced control algorithms to achieve closed-loop control. When the actual pressure... Less than the target pressure force At this time, the PLC controller increases the control signal, causing the hydraulic control valve group to increase the oil supply pressure, increasing the output thrust of the hydraulic cylinder, and increasing the pressure applied by the compaction head; when the actual pressure... Greater than the target pressure force At this time, the PLC controller reduces the control signal, causing the hydraulic control valve group to reduce the oil supply pressure, reducing the output thrust of the hydraulic cylinder, and thus reducing the pressure applied by the compaction head. Through continuous negative feedback adjustment, the actual pressure... Gradually approaching the target and increasing strength When the pressure deviation is less than the set threshold, the target is considered achieved. The PLC controller controls the hydraulic control valve group to maintain the current output, and each compaction head maintains the compaction state for a certain period of time to complete the compaction. The time to maintain the compaction state needs to be determined based on the curing speed of the hardener and the stress relaxation characteristics of the hole-protecting material. Too short a pressure holding time will lead to insufficient compaction, while too long a pressure holding time will reduce construction efficiency. The preferred pressure holding time range is 5s to 20s. Within this time range, it can ensure that the hole-protecting material is fully compacted while maintaining high construction efficiency. During the pressure holding process, the curing reaction of the hardener continues, the hole-protecting material gradually hardens, and the density is further improved. After the pressure holding is completed, the hole-protecting layer has sufficient strength and can proceed to the next step.

[0097] Through the aforementioned multi-parameter coupled adaptive compaction process, the compaction force is dynamically adjusted based on real-time monitored parameters such as density, temperature, humidity, and borehole wall pressure, adapting to the compaction requirements under different construction conditions. Compared to fixed compaction force methods, this adaptive compaction method can automatically increase the compaction force to compensate for adverse environmental factors when temperatures are low or humidity is unfavorable, and automatically decrease the compaction force to avoid over-compaction when temperatures are high or borehole wall pressure is abnormal, thus achieving ideal compaction results under various construction conditions. Furthermore, closed-loop control ensures that the actual compaction force accurately tracks the target compaction force, eliminating the influence of hydraulic system characteristic differences and frictional resistance on the compaction force, guaranteeing consistent compaction force applied to each compaction point in the circumferential direction, and improving compaction uniformity. Precise control of the actual compaction force also avoids deformation or cracking of the borehole protection layer due to excessive compaction force, and insufficient density due to insufficient compaction force, improving the stability and reliability of borehole protection quality.

[0098] Step S6: Device Upward Movement and Cyclic Construction Stage; After the single-layer protective material is compacted, the protective device needs to be moved upward a certain distance. Then, the operations of waste collection, curing agent spraying, and compaction are repeated to form the next layer of protective material. Through cyclic construction, layer by layer, a multi-layer protective structure is formed. Compared with a single-layer structure, the multi-layer structure has better mechanical properties and reliability. The layers are reasonably overlapped to form an integral structure, avoiding the problem of insufficient internal compaction caused by an excessively thick single layer.

[0099] After compaction, firstly, the hydraulic control valve group is controlled to retract the piston rods of each hydraulic cylinder, causing the compaction head to retract radially to its initial position, disengaging from the protective hole layer. Then, the piston rod of the hydraulic drive cylinder is controlled to contract, driving the lifting slider to move upwards along the guide rail. The entire protective hole device moves upwards accordingly, with the upward movement distance... Precise control is required to ensure a proper overlap between adjacent protective layers. Upward movement distance. The calculation formula is: ;in: The upward movement distance of the device is expressed in millimeters (mm). The thickness of a single layer of protective material is measured in millimeters (mm). Interlayer overlap, expressed in millimeters (mm). The preferred value is 15% to 30%, that is, the upward shift distance Less than the thickness of a single layer This design creates a certain overlap between the bottom of the next layer of protective material and the top of the previous layer. This overlap is significant because the two layers interlock within the overlap area, and the curing agent forms a chemical bond between them, greatly enhancing the interlayer bonding strength and avoiding the problem of insufficient bonding strength caused by the natural adhesion between adjacent protective layers. The selection of the interlayer overlap amount needs to comprehensively consider interlayer bonding strength and construction efficiency. Too little overlap will lead to insufficient interlayer bonding strength, easily resulting in delamination or peeling during use; too much overlap will increase the total number of protective layers, reduce construction efficiency, and may also lead to over-compaction in the overlapping area and under-compaction in the non-overlapping area. The preferred overlap range is 15% to 30% of the single-layer thickness, within which sufficient interlayer bonding strength is ensured while maintaining high construction efficiency.

[0100] After the device is moved upwards, the bottom of the hollow rotating cylinder of the hole-protecting device is at the new working height. The scraper is aligned with the waste accumulation area of ​​the new layer, and then steps S2 to S5 are repeated, including waste collection and discharge, curing agent spraying, multi-sensor data fusion, and multi-parameter coupled adaptive compaction, forming a new layer of hole-protecting material. The construction process of each layer follows the same procedure, but due to the differences in depth and environmental conditions of each layer, multi-sensor data fusion and adaptive compaction control will automatically adjust the control parameters according to the actual situation to ensure that each layer achieves the ideal compaction effect. For example, as the height of the hole-protecting layer increases, the ambient temperature may change, and the hole wall pressure will also change due to the depth change. The extended Kalman filter algorithm and the multi-parameter coupled compaction force calculation model will automatically adapt to these changes and dynamically adjust the compaction control parameters.

[0101] Step S7: Complete the hole protection stage. By repeatedly executing steps S2 to S6, a multi-layered progressive hole protection structure is formed layer by layer. The total height of the hole protection structure... It can be based on the number of completed protective layers. The calculation is performed using the following formula: ;in: The total height of the hole protection structure is in millimeters (mm). The number of completed hole protection layers indicates the number of hole protection material layers that have been compacted. The upward movement distance for a single layer is expressed in millimeters (mm). This refers to the thickness of a single layer of protective material, expressed in millimeters (mm). The formula means that the thickness of the first layer of protective material is... Starting from the second layer, each additional layer of protective material increases the total height. ,therefore The total height of the protective layer material is equal to the thickness of the first layer. Plus subsequent Increased height of the layer After simplification, it becomes This formula takes into account the effect of interlayer overlap, due to the upward movement distance each time. Less than the thickness of a single layer Since there is overlap between adjacent layers, the total height of the multi-layer perforated structure is less than the simple sum of the thicknesses of each layer.

[0102] During construction, the PLC controller calculates the total height of the current protective hole structure in real time. This calculated total height is compared to the preset target total height. The preset total height is determined based on the borehole depth, formation stability, and borehole support structure design requirements. For shallow boreholes or formations with good stability, the borehole support height can be appropriately reduced; for deep boreholes or formations with poor stability, the borehole support height needs to be appropriately increased to provide sufficient borehole wall support. The calculated total height... When the preset total height is reached or exceeded, the PLC controller stops the cyclic construction, completing the entire borehole protection operation. At this point, a complete borehole protection structure composed of multiple layers of protection material has been formed at the borehole opening. Each layer of this structure has undergone precise compaction control, resulting in high and uniform density. The layers are tightly bonded together through overlapping areas, forming a whole with excellent mechanical properties and durability. After the borehole protection structure is completed, drilling operations or other subsequent construction operations can continue. The borehole protection structure provides reliable borehole wall support, preventing borehole wall collapse and deformation, and ensuring the smooth progress of subsequent construction.

[0103] This invention provides a progressive borehole protection method based on layered compaction. Through on-site utilization of waste materials, precise injection of curing agent, multi-sensor data fusion, and multi-parameter coupling adaptive compaction, it achieves efficient utilization of borehole protection materials, high density and uniformity of the borehole protection layer, and adaptive control of the borehole protection process. On-site utilization of waste materials reduces construction costs and environmental burden; precise injection of curing agent ensures the curing quality of the borehole protection layer; multi-sensor data fusion eliminates measurement noise and improves control accuracy; multi-parameter coupling adaptive compaction adapts the compaction process to different construction environmental conditions; and progressive layered construction combined with interlayer overlap design forms a high-quality multi-layer integral borehole protection structure. This method is applicable to borehole protection operations of various formation types and borehole diameters. Parameters can be flexibly adjusted according to specific construction conditions, improving construction efficiency while ensuring borehole protection quality and meeting complex and ever-changing engineering needs. Those skilled in the art can implement this borehole protection method based on the above description. In practical applications, it may be necessary to appropriately adjust some parameters based on factors such as the specific properties of waste materials, type of curing agent, performance of compaction equipment, and formation characteristics, but these adjustments are all within the scope of the technical solution of this invention.

[0104] Example 1: This example uses drilling and protection construction in clay strata as an application scenario. The borehole diameter is 300mm, and the outer diameter of the protection layer is... The inner diameter of the protective layer is 0.18m. The height is 0.15m, and the preset total height of the protective hole is 500mm.

[0105] The progressive hole protection device based on layered compaction used in this embodiment includes a lifting and adjusting mechanism, a hole protection forming assembly, a layered compaction mechanism, a sensor system, and a control system. In the lifting and adjusting mechanism, the back plate 1 is fixed to the drilling rig frame, the guide rail 2 is fixed vertically to the back plate 1, the lifting slider 5 is slidably connected to the guide rail 2, and the cylinder body of the hydraulic drive cylinder 4 is fixed to the back plate 1 with its piston rod connected to the lifting slider 5. In the hole protection forming assembly, the support frame 6 is fixed to the lifting slider 5, the hollow rotary drum is rotatably connected to the support frame 6, and the drive motor 13 is fixed to the support frame 6 and drives the hollow rotary drum to rotate through the meshing of the drive gear 14 and the driven gear 12. Four adjustable nozzles 17 are installed inside the upper cylinder 101, a waste outlet 15 is opened on the side wall of the lower cylinder 102, and six scrapers 18 are fixed at the bottom. In the layered compaction mechanism, the compaction ring 28 is fixed to the bottom of the lower cylinder 102, and eight telescopic pressure heads 29 are distributed at equal angles along the circumference of the compaction ring 28. Each telescopic pressure head 29 includes a hydraulic cylinder body 291 and a compaction head 292. The sensor system includes eight pressure sensors 30, four density sensors 37, two temperature sensors 22, two humidity sensors 38, and four borehole wall pressure sensors 39. The control system includes a data acquisition unit 52, a PLC controller 50, and a hydraulic control valve group 53. The PLC controller 50 has a built-in extended Kalman filter algorithm module and a multi-parameter coupled pressure calculation module. The borehole protection method of this embodiment includes the following steps.

[0106] Step S1 is drilling and device positioning. S11 sets the single drilling depth to 3m based on the characteristics of the clay strata. S12 controls the drilling rig to descend to a depth of 3m and then stops drilling. S13 controls the piston rod of the hydraulic drive cylinder 4 to extend, adjusting the lifting slider 5 to move downwards along the guide rail 2, causing the hollow rotary drum to move down to the borehole opening, with the scraper 18 positioned in the waste accumulation area, thus completing device positioning.

[0107] Step S2 is waste collection and discharge. S21: Start the drive motor 13 and set the rotation speed of the hollow drum to 30 rpm. S22: The scraper 18, rotating with the hollow drum, scrapes the waste material from the borehole opening into the inner cavity of the hollow drum. S23: Under centrifugal force, the waste material is thrown out from the waste outlet 15, evenly distributed around the borehole wall to form a single layer of protective material, with a single layer thickness of... Set to 35mm.

[0108] Step S3 is the application of the curing agent. S31 is based on the formula... Calculate the amount of hardener sprayed, where m, m, m, Calculated L. S32 controls the adjustable nozzle 17 to spray according to the calculated spray volume, and the curing agent mixes with the waste to form a cured protective layer.

[0109] Step S4 involves multi-sensor data fusion. In step S41, data acquisition unit 52 acquires the raw measurement values ​​from each sensor at a sampling period of 100ms, forming an observation vector. The S42 PLC controller 50 estimates the state a posteriori value from the previous cycle. Obtain the prior state estimate for the current period S43 Calculate the prior covariance matrix The process noise covariance matrix The settings are based on system characteristics. S44 calculates the Kalman gain matrix. S45 updates the state based on the Kalman gain matrix. The output fused state estimate includes the density estimate. Temperature estimate Humidity estimates and estimated borehole wall pressure S46 Updated A posteriori covariance matrix After completing one filtering cycle, return to S41.

[0110] Step S5 is multi-parameter coupled adaptive compaction. S51 The PLC controller 50 receives the fused state estimate output from step S4. S52 Calculates the temperature correction coefficient. ,in Set to 20℃. S53 calculates the humidity correction factor. ,in Set to 15%. S54 calculates the orifice wall pressure correction factor. ,in The pressure is set to 50 kPa. The S55 calculates the target pressure. ,in Set to 80kN, The value is set to 0.92. The S56 hydraulic control valve group 53 controls the synchronous operation of each hydraulic cylinder 291, driving the compaction head 292 to apply pressure to the protective hole layer. The PLC controller 50 uses closed-loop control to adjust the actual pressure. Tracking target pressure force Once the target is reached, maintain the compacted state for 10 seconds to complete the compaction.

[0111] Step S6 involves the upward movement of the device and cyclic construction. After compaction is completed in S61, the piston rods of each hydraulic cylinder 291 are retracted. Step S62 is performed according to the formula... The upward movement distance of the computing device, of which mm, Pick 20% of that, or 7mm, is calculated as follows: mm. S63 controls the hydraulic drive cylinder 4 to retract, causing the hole protector to move upward by 28mm, and repeats steps S2 to S5.

[0112] Step S7 completes the hole protection. Repeat steps S2 to S6, according to the formula. Calculate the total height of the hole protection structure when hour Once the preset total height of 500mm is reached, the construction cycle will stop.

[0113] Example 2: This example uses drilling and protection construction in sandy soil as an application scenario. The borehole diameter is 400mm, and the outer diameter of the protection layer is... The inner diameter of the protective layer is 0.24m. The thickness is 0.20m, and the preset total height of the protective hole is 800mm. Compared with Example 1, the main parameter differences in this example are as follows: Single layer thickness The diameter is set to 50mm, the rotation speed of the hollow drum is set to 40rpm, and the volume ratio of curing agent to waste is set accordingly. The setting is 0.40, the holding time is set to 15 seconds, and the interlayer overlap is set to... Pick 25% of that, or 12.5mm, is the upward movement distance of the device. mm. Reference pressure. Set to 100kN, target density Set to 0.90. Calculations show that when... hour Once the preset total height is reached (mm), the construction cycle will stop.

[0114] Example 3: This example uses drilling and protection construction in rock formations as an application scenario. The borehole diameter is 250mm, and the outer diameter of the protection layer is... The inner diameter of the protective layer is 0.15m. The thickness is 0.125m, and the preset total height of the protective hole is 400mm. Compared with Example 1, the main parameter differences in this example are as follows: Single layer thickness The diameter is set to 20mm, the rotation speed of the hollow drum is set to 20rpm, and the volume ratio of the curing agent to the waste material is set accordingly. The value is set to 0.25, the holding time is set to 20 seconds, and the interlayer overlap is set to... Pick 30%, or 6mm, is the upward movement distance of the device. mm. Reference pressure. Set to 120kN, target density Set to 0.95. Calculations show that when... hour Once the preset total height is reached (mm), the construction cycle will stop.

[0115] Comparative Example 1 is the same as Example 1 in terms of application scenario and device structure. The main difference is that step S4 does not use the extended Kalman filter algorithm for multi-sensor data fusion, but directly uses the original measurement values ​​of each sensor as the input parameters for subsequent pressure force calculation. Other steps are the same as in Example 1.

[0116] Comparative Example 2 shares the same application scenario and device structure as Example 1. The main difference lies in step S5, which uses a fixed compaction force instead of a multi-parameter coupled adaptive compaction method. The compaction force is fixed at 80 kN and is not adjusted based on environmental factors such as temperature, humidity, or borehole wall pressure. Other steps are the same as in Example 1.

[0117] Experiment 1 is a comparative experiment on the estimation error of compaction state between Example 1 and Comparative Example 1. In this experiment, both Example 1 and Comparative Example 1 were carried out under the same clay stratum construction conditions. The data acquisition unit 52 continuously acquired the measurement data of the compaction sensor 37 for 100 cycles at a sampling period of 100ms. Example 1 used the extended Kalman filter algorithm built into the PLC controller 50 to fuse the sensor data, while Comparative Example 1 directly used the raw measurement values ​​of the compaction sensor 37. The experimental results are as follows. Figure 3 As shown. Figure 3 The horizontal axis represents the sampling period number, and the vertical axis represents the state estimation error. The state estimation error is defined as the difference between the estimated value and the true value, which is obtained through a high-precision calibration device. Figure 3 The solid line represents the estimation error curve after fusion using extended Kalman filtering in Example 1, while the dashed line represents the error curve of Comparative Example 1 using the original measured values ​​directly.

[0118] from Figure 3 As can be observed, the error curve of Comparative Example 1 fluctuates significantly more than that of Example 1. The error value of Comparative Example 1 fluctuates wildly within a range of ±0.08, while the error value of Example 1 is consistently controlled within a range of ±0.02. This phenomenon indicates that the Extended Kalman Filter (EPF) algorithm has a significant suppression effect on sensor measurement noise. The EPF establishes a state transition model and an observation model, uses prior knowledge of the system to predict the current state, and then optimally weights and fuses the predicted and measured values ​​according to the Kalman gain. When the measurement noise is high, the algorithm automatically reduces the confidence level in the measured values, thereby suppressing noise propagation. Figure 3 The results show the effectiveness of using extended Kalman filtering for multi-sensor data fusion. Based on the noise suppression effect of the data fusion algorithm, the subsequent multi-parameter coupled compaction force calculation in step S5 obtains accurate and reliable input parameters, thereby achieving precise adaptive compaction control.

[0119] Experimental Example 2 is a comparative experiment of the root mean square errors of various parameters in Example 1 and Comparative Example 1, comparing the estimation accuracy of different state parameters. The experimental results are as follows: Figure 4 As shown. Figure 4 Neutron plot (a) shows the comparison of root mean square error of compaction. Figure 4 Neutron plot (b) shows the comparison of root mean square error of temperature. Figure 4 Neutron plot (c) shows the comparison of root mean square error of humidity. Figure 4 The neutron plot (d) shows the comparison of the root mean square error (RMSE) of the borehole wall pressure. RMSE is a commonly used indicator to measure the accuracy of estimation. It is calculated by taking the square root of the mean of the squares of the estimation errors at each sampling time. The smaller the RMSE value, the higher the estimation accuracy. Figure 4 The blue bars represent the RMSE value of Example 1, and the red bars represent the RMSE value of Comparative Example 1.

[0120] from Figure 4 Neutron plot (a) shows that the RMSE of Example 1 is 0.0082, while that of Comparative Example 1 is 0.0315, representing a 74.0% reduction in density compared to Comparative Example 1. From... Figure 4 Neutron plot (b) shows that the RMSE of Example 1 was 0.42℃, while that of Comparative Example 1 was 1.85℃, representing a 77.3% reduction in temperature compared to Comparative Example 1. From... Figure 4 As can be observed from the neutron plot (c), the humidity RMSE of Example 1 was 0.68%, while that of Comparative Example 1 was 2.93%, representing a 76.8% reduction in humidity compared to Comparative Example 1. From... Figure 4 As can be observed from the neutron plot (d), the RMSE of the pore wall pressure in Example 1 is 1.24 kPa, while that in Comparative Example 1 is 5.67 kPa, representing a 78.1% reduction in RMSE compared to Comparative Example 1. Figure 4 The results show that the Extended Kalman Filter (EKF) algorithm significantly improves the estimation accuracy of four state parameters: compaction, temperature, humidity, and pore wall pressure, reducing the estimation error by an average of approximately 74% to 78%. The EKF algorithm utilizes observation information from multiple sensors for joint estimation, dynamically adjusting the fusion weights of each sensor's data through the covariance matrix, thus fully leveraging the complementary advantages of redundant information from multiple sensors. Based on the high-precision state estimates obtained by this data fusion algorithm, the present invention accurately calculates the temperature correction coefficient in step S5. Humidity correction factor and hole wall pressure correction factor This enables adaptive pressure regulation through multi-parameter coupling.

[0121] Experimental Example 3 compares the density distribution of the borehole protection layer between Example 1 and Comparative Example 2. In this experiment, both Example 1 and Comparative Example 2 completed the entire borehole protection construction process under the same clay stratum construction conditions, forming a total of 17 layers of borehole protection material. Example 1 employed the multi-parameter coupled adaptive compaction method described in step S5, calculating the target compressive strength based on the estimated values ​​of the fused density, temperature, humidity, and borehole wall pressure state, and implementing closed-loop control. Comparative Example 2 used a fixed compressive strength method, setting the compressive strength constant at 80 kN without adjustment based on environmental factors. After the borehole protection construction was completed, the density of each layer of borehole protection material was measured using a nuclear density meter according to the JTG3450-2019 standard. The experimental results are as follows: Figure 5 As shown. Figure 5 The horizontal axis represents the number of the protective layer, the vertical axis represents the density value, the solid line with a circular mark represents the density of each layer in Example 1, and the dashed line with a square mark represents the density of each layer in Comparative Example 2.

[0122] from Figure 5 As can be seen, the density of the 17 layers of hole-protecting material in Example 1 is distributed in the range of 0.90 to 0.95, with an average value of 0.923. The density curves of each layer are stable and have small fluctuations. In contrast, the density of the 17 layers of hole-protecting material in Comparative Example 2 is distributed in the range of 0.82 to 0.92, with an average value of 0.876. The density curves of each layer fluctuate significantly and have multiple low-value points. Figure 5 The results show that the multi-parameter coupled adaptive compaction method can increase the average density of the borehole protection layer by 5.4% compared with the fixed compaction method, while also significantly improving the consistency of the density of each layer. During borehole construction, the ambient temperature and humidity change with time and depth. Temperature affects the reaction rate of the curing agent and the plasticity of the borehole protection material, while humidity affects the moisture content and compactability of the material. Borehole wall pressure reflects changes in formation constraints. When using a fixed compaction method, insufficient compaction leads to a decrease in density under conditions of low temperature or humidity deviating from the optimal value, while excessive compaction may cause deformation of the borehole protection layer under conditions of high temperature or excessive borehole wall pressure. This invention utilizes the temperature correction coefficient in step S5... Humidity correction factor and hole wall pressure correction factor The target compaction force is adjusted in real time to adapt to the current environmental conditions, thereby achieving the ideal compaction effect under different construction conditions.

[0123] Experimental Example 4 compares the coefficient of variation (CV) of compaction density between Examples 1 to 3 and Comparative Example 2. In this experiment, borehole protection construction was carried out under the conditions of clay soil in Example 1, sandy soil in Example 2, and rocky soil in Example 3. Simultaneously, under the clay soil condition, the fixed compressive strength method of Comparative Example 2 was used as a control. After the borehole protection construction was completed, eight equally divided measuring points were selected along the circumference of the borehole protection layer. The compaction density at each measuring point was measured using a nuclear density meter, and the coefficient of variation (CV) of compaction density was calculated. The coefficient of variation (CV) is defined as the standard deviation. Compared with the average Multiply the ratio by 100%, and the smaller the CV value, the better the compaction uniformity. Experimental results are as follows: Figure 6 As shown. Figure 6 The horizontal axis represents the names of each embodiment and comparative example, and the vertical axis represents the coefficient of variation of density. The blue bar represents Example 1, the green bar represents Example 2, the purple bar represents Example 3, and the red bar represents Comparative Example 2.

[0124] from Figure 6 As can be seen, the coefficient of variation for compaction in Example 1 is 3.2%, in Example 2 it is 3.8%, in Example 3 it is 2.9%, and in Comparative Example 2 it is 8.7%. The coefficients of variation for Examples 1 to 3 are all less than 5%, while the coefficient of variation for Comparative Example 2 is close to 9%. The compaction uniformity of each example of the present invention is significantly better than that of Comparative Example 2. Figure 6 The results show that the method of the present invention can maintain good compaction uniformity under different geological conditions. The coefficient of variation of Example 3 under rock geological conditions is even better than that of clay and sandy geological conditions. The present invention uses multiple telescopic pressure heads 29 distributed at equal angles along the circumference of the compaction ring 28. The hydraulic control valve group 53 controls the output pressure of each hydraulic cylinder 291 through a multi-proportional valve to keep the pressure applied by each compaction head 292 consistent. At the same time, the PLC controller 50 detects the actual pressure of each telescopic pressure head 29 in real time through the pressure sensor 30, and independently adjusts the pressure heads with large deviations to ensure uniform distribution of pressure in the circumferential direction. Although Comparative Example 2 also uses multiple telescopic pressure heads 29, due to the use of a fixed pressure and the lack of closed-loop adjustment, the differences in the hydraulic system and frictional resistance between the pressure heads cause deviations in the actual pressure, ultimately resulting in uneven compaction.

[0125] Experimental Example 5 is a comparative experiment on the compressive strength tracking of Example 1. In this experiment, the target compressive strength was recorded within one complete compaction cycle during the construction process of Example 1. and actual pressure The time-series data, with a total compaction cycle duration of 10 seconds and a data sampling interval of 0.1 seconds, contains a total of 100 data points. Target compaction force. The actual pressure is calculated by the PLC controller 50 according to the formula in step S5. The pressure was obtained in real time by pressure sensor 30. The experimental results are as follows: Figure 7 As shown, Figure 7 The horizontal axis represents time, the vertical axis represents pressure force, the solid line represents the target pressure force curve, and the dashed line represents the actual pressure force curve.

[0126] from Figure 7 As can be seen, the target pressure gradually increases from 0 to 82.5 kN from 0 to 3 seconds, and remains stable at 82.5 kN from 3 seconds to 10 seconds. The actual pressure tracks the changes in the target pressure. There is a response delay of about 0.2 seconds during the rising phase, and the actual pressure fluctuates slightly around the target value during the stable phase. The steady-state error is controlled within 2 kN, that is, the relative error is less than 2.5%. Figure 7 The results show that the closed-loop pressure control system adopted in this invention has good tracking performance and steady-state accuracy. The PLC controller 50 transmits the target pressure... Compared with actual pressure The system compares the actual pressure with the target value and adjusts the valve opening of the hydraulic control valve group 53 based on the deviation signal. When the actual pressure is less than the target value, the valve opening is increased to increase the output thrust of the hydraulic cylinder 291. When the actual pressure is greater than the target value, the valve opening is decreased to decrease the output thrust. Through continuous negative feedback adjustment, the actual pressure gradually approaches the target value. The hydraulic control valve group 53 uses a multi-proportional valve group, which has a fast response speed and high control accuracy, ensuring the dynamic performance of pressure tracking. The multi-parameter coupled target pressure calculated in step S5 is accurately applied to the borehole layer, thereby achieving the expected adaptive compaction effect.

[0127] Experimental Example 6 is a comparative experiment on the compressive strength distribution of the protective layer in Example 1 and Comparative Example 2. In this experiment, after the protective layer construction of Example 1 and Comparative Example 2 was completed, it was cured for 28 days. Then, according to GB / T50081-2019 standard, cylindrical core samples with a diameter of 50 mm were drilled from each layer of protective material using the core drilling sampling method. The compressive strength of each core sample was measured using a universal testing machine. The experimental results are as follows: Figure 8 As shown. Figure 8 The horizontal axis represents the names of the examples and comparative examples, the vertical axis represents the 28-day compressive strength, and the box plot shows the median, interquartile range, and outlier distribution of each group of data. The blue box represents the compressive strength distribution of Example 1, and the red box represents the compressive strength distribution of Comparative Example 2.

[0128] from Figure 8 As can be seen, the median compressive strength of Example 1 is approximately 4.8 MPa, with an interquartile range of 4.5 MPa to 5.1 MPa. The data distribution is concentrated and there are no obvious outliers. The median compressive strength of Comparative Example 2 is approximately 3.9 MPa, with an interquartile range of 3.5 MPa to 4.3 MPa. The data distribution is more dispersed. Figure 8 The results show that the average compressive strength of the protective layer in Example 1 is 4.82 MPa, while that in Comparative Example 2 is 3.91 MPa, representing a 23.3% increase compared to Comparative Example 2. The compressive strength of the protective layer is closely related to its density. Higher density results in a larger contact area between the particles of the protective material, lower porosity, and more effective bonding by the curing agent, ultimately leading to increased compressive strength. This invention improves the density and uniformity of the protective layer through a multi-parameter coupled adaptive compaction method, thereby increasing the overall strength of the protective layer. Furthermore, because the density consistency of each layer in Example 1 is better, the dispersion of compressive strength is significantly less than that in Comparative Example 2. This means that the protective structure has higher reliability and will not be damaged by local weak layers.

[0129] Experiment 7 is an experiment demonstrating the convergence of the density estimate during the extended Kalman filter process. In this experiment, the actual density of the protective layer in Example 1 was set to a constant 0.90, and the initial state estimate of the extended Kalman filter algorithm was set to 0.82. The changes in the state estimate were recorded over 50 cycles of the filter algorithm. The experimental results are as follows: Figure 9 As shown, Figure 9 The horizontal axis represents the filtering period, the vertical axis represents the density value, the green solid line represents the true density value, the gray dotted line represents the original measurement value, and the blue solid line represents the extended Kalman filter estimate.

[0130] from Figure 9 It can be observed that the original measured value fluctuates wildly around the true value of 0.90, with a fluctuation range of approximately ±0.05. The extended Kalman filter estimate starts from the initial value of 0.82, converges rapidly to the true value in the first 15 periods, and stabilizes around the true value in the 15 to 50 periods, with a fluctuation range of approximately ±0.01. Figure 9 The results show that the Extended Kalman Filter (EKF) algorithm has good convergence and steady-state accuracy, and can converge to the true value in a short time even if the initial estimate deviates significantly from the true value. The EKF uses the posterior covariance matrix... Dynamically describing the uncertainty of state estimation, a larger covariance in the early stages of algorithm operation indicates high estimation uncertainty, and the Kalman gain... A larger corresponding value allows the algorithm to accept more measured values, thus quickly correcting estimation biases. As the filtering period increases, the covariance gradually decreases, indicating improved estimation accuracy. The Kalman gain decreases accordingly, allowing the algorithm to accept more predicted values, thereby suppressing measurement noise. In step S4 of this invention, the extended Kalman filter algorithm utilizes this adaptive adjustment mechanism. Even if there are deviations in the initial conditions or interference with the sensors during the hole protection construction process, the algorithm can automatically recover and continuously output high-precision state estimates.

[0131] Experiment Example 8 is a comparative experiment on compaction effects under different temperature conditions. In this experiment, borehole protection construction was carried out under 20 different temperature conditions ranging from 5℃ to 40℃. For each temperature condition, Example 1 used a multi-parameter coupled adaptive compaction method, while Comparative Example 2 used a fixed compaction method. The density of the borehole protection layer was measured after construction. The experimental results are as follows: Figure 10 As shown, Figure 10 The horizontal axis represents the ambient temperature, the vertical axis represents the density of the protective layer, the blue dots represent the density of Example 1 under various temperature conditions, the red square dots represent the density of Comparative Example 2 under various temperature conditions, and the solid and dashed lines represent the linear trend lines of Example 1 and Comparative Example 2, respectively.

[0132] from Figure 10 As can be observed, in Example 1, the density values ​​ranged from 0.91 to 0.93 within the temperature range of 5°C to 40°C, and the trend line was basically horizontal, indicating that the density was not significantly correlated with temperature. In Comparative Example 2, the density values ​​ranged from 0.84 to 0.92, and the trend line showed a clear inverted V-shape, that is, the density was highest near 20°C, while the density decreased significantly under low and high temperature conditions. Figure 10 The results show that the multi-parameter coupled adaptive compaction method of the present invention can effectively eliminate the influence of temperature changes on the compaction effect, while the compaction effect of the fixed compaction method is significantly affected by temperature. Temperature affects the curing reaction rate of the curing agent and the mechanical properties of the pore-protecting material. At low temperatures, the curing reaction is slower and the material has poorer plasticity, requiring a greater compaction force to achieve the same density. At high temperatures, the curing reaction is faster and the material is prone to premature hardening, which also affects the compaction effect. In sub-step S52 of step S5 of the present invention, a temperature correction coefficient is used... Correction is applied to the target pressure when the temperature is below the reference temperature. Time correction factor A value less than 1 increases the target pressure; when the temperature is higher than the reference temperature, the correction factor is applied. A value greater than 1 reduces the target compaction force, thereby compensating for the effect of temperature changes on compaction. Figure 10 The temperature correction factor was intuitively verified. The design rationality and practical effect of the present invention prove that the multi-parameter coupled compressive strength calculation model can adapt to construction environments under different temperature conditions.

[0133] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A progressive hole-protection method based on layered compaction, characterized in that, Includes the following steps: S1. Drilling and Equipment Positioning: After the drilling rig has drilled to the preset depth, the hydraulic drive cylinder is controlled to adjust the lifting slider to move along the guide rail, so that the hollow rotary drum moves down to the borehole opening to complete the positioning. S2. Waste collection and discharge: The drive motor is started and the hollow drum is driven to rotate through the meshing of the drive gear and the driven gear. The scraper at the bottom of the lower drum scrapes the waste into the hollow drum. The waste is discharged from the waste outlet under the action of centrifugal force and is evenly distributed around the borehole wall to form a single layer of hole protection material. S3. Curing agent spraying: While the waste is being discharged, the adjustable nozzle in the upper cylinder sprays the curing agent downwards, and the curing agent mixes with the waste to form a cured protective layer. S4. Multi-sensor data fusion: The data acquisition unit collects detection data from density sensor, temperature sensor, humidity sensor, orifice wall pressure sensor and pressure sensor. The PLC controller uses an extended Kalman filter algorithm to fuse the multi-sensor data and outputs the fused state estimate. S5. Multi-parameter coupling adaptive compaction: The PLC controller calculates the target compaction force of multi-parameter coupling based on the estimated values ​​of the fused density, temperature, humidity and borehole wall pressure. The hydraulic control valve group controls the hydraulic cylinder of each telescopic pressure head to drive the compaction head to extend radially and adaptively compact the protective borehole layer. S6. Device moving upward and cyclic construction: After compaction is completed, control each telescopic pressure head to retract, and use the hydraulic drive cylinder to move the hole protection device upward by a preset distance. Repeat steps S2 to S5. S7. Complete the hole protection: Repeat steps S2 to S6 to accumulate layers to form a multi-layer progressive hole protection structure until the preset total height is reached.

2. The progressive hole protection method based on layered compaction according to claim 1, characterized in that: In step S1, the single drilling depth is set according to the formation type, the drilling rig is controlled to stop after drilling to the set depth, and then the hydraulic drive cylinder is controlled to extend and retract to move the hollow rotating drum down so that the scraper is located in the waste accumulation area at the borehole opening. In step S2, the rotation speed of the hollow drum is set to 20 rpm to 40 rpm. After the waste material is discharged from the waste outlet, a single layer of protective material is formed, with a single layer thickness δ of 20 mm to 50 mm. In step S3, the amount of curing agent sprayed is calculated based on the volume of the single-layer protective material layer. The calculation formula is: ;in, The amount of curing agent sprayed (L); Pi; The outer diameter of the protective layer (m); The inner diameter of the protective layer (m); The thickness (m) of a single layer of protective hole material; The volume ratio of curing agent to waste material should be between 0.25 and 0.40; control the adjustable nozzle to spray at the calculated rate. Perform the spraying.

3. The progressive hole protection method based on layered compaction according to claim 1, characterized in that, Step S4 includes the following sub-steps: S41. The data acquisition unit acquires the raw measurement values ​​of each sensor at a fixed sampling period to form an observation vector. ; S42. The PLC controller estimates the state posterior value from the previous cycle. Obtain the prior state estimate for the current period ; S43. Calculate the prior covariance matrix The calculation formula is: ;in, for The prior covariance matrix at time t; for The posterior covariance matrix at time t; The process noise covariance matrix; S44. Calculate the Kalman gain matrix. The calculation formula is: ; in, for Kalman gain matrix at time step; The prior covariance matrix; The observation matrix; for The transpose of the matrix; To observe the noise covariance matrix; Invert a matrix; S45. Update the state based on the Kalman gain matrix, calculated using the following formula: ;in, for The posterior estimate of the state at time 1; These are prior state estimates; The Kalman gain matrix; The observation vector is used; the output is the fused state estimate, including the density estimate. Temperature estimate Humidity estimates and estimated borehole wall pressure ; S46. Update the posterior covariance matrix The calculation formula is: ;in, for The posterior covariance matrix at time t; It is the identity matrix; The Kalman gain matrix; The observation matrix; The prior covariance matrix is ​​used; after completing one filtering cycle, return to step S41 to enter the next cycle.

4. The progressive hole protection method based on layered compaction according to claim 1, characterized in that, Step S5 includes the following sub-steps: S51. The PLC controller receives the fused state estimate output from step S4, including the density estimate. Temperature estimate Humidity estimates and estimated borehole wall pressure ; S52. Calculate the temperature correction factor The calculation formula is: ; in, This is a temperature correction factor; The estimated temperature after fusion (°C); 0.02 is the reference temperature (°C); 10 is the temperature normalization coefficient (°C); S53. Calculate the humidity correction factor The calculation formula is: ;in, This is the humidity correction factor; The estimated humidity value (%) after fusion; 0.15 represents the optimal humidity (%); 0.15 is the humidity influence coefficient. S54. Calculate the correction factor for borehole wall pressure. The calculation formula is: ;in, This is the correction factor for the borehole wall pressure; This is an operation to find the minimum value; This is for calculating the maximum value. This represents the estimated pressure (kPa) on the fused pore wall. The reference borehole wall pressure (kPa) is 0.1; the borehole wall pressure influence coefficient is 0.8; the lower limit of the correction coefficient is 1.2; S55. Calculate the target pressure force The calculation formula is: ;in, Apply force (kN) to the target; The baseline compressive strength (kN); For target density; This is the current density estimate after fusion; This is a temperature correction factor; This is the humidity correction factor; This is the correction factor for the borehole wall pressure; S56. The hydraulic control valve assembly is based on the target pressure. The hydraulic cylinders are controlled to move synchronously, driving the compaction head to extend radially and apply pressure to the protective hole layer. The pressure sensor detects the actual pressure in real time. The PLC controller adjusts the output of the hydraulic control valve group through closed-loop control to achieve the actual pressure. Tracking target pressure force After reaching the target, maintain the compaction state for 5 to 20 seconds to complete the compaction.

5. The progressive hole protection method based on layered compaction according to claim 1, characterized in that: In step S6, after compaction is completed, the hydraulic control valve group controls the piston rods of each hydraulic cylinder to retract, and then controls the hydraulic drive cylinder to contract, causing the hole protection device to move upward along the guide slide rail, with an upward movement distance of... The calculation formula is: ;in, The upward movement distance of the device (mm); The thickness (mm) of a single layer of protective hole material; The interlayer overlap (mm) is a value that is taken from the value of the layer overlap. 15% to 30%; In step S7, the total height of the hole protection structure Based on the number of completed layers The calculation formula is as follows: ;in, The total height of the hole protection structure (mm); This represents the number of completed protective layers. The upward movement distance for a single layer is (mm). The thickness of a single-layer protective material layer (mm); when The construction cycle will stop when the preset total height is reached.

6. A progressive hole-protecting device based on layered compaction, used to implement the method according to any one of claims 1 to 5, characterized in that, include: The lifting and adjusting mechanism includes a back plate fixed on the drilling rig, a guide rail fixed on the back plate extending vertically, a lifting slider slidably connected to the guide rail, and a hydraulic drive cylinder with its cylinder body fixed on the back plate and its piston rod connected to the lifting slider. The hole forming assembly includes a support frame fixed on a lifting slider, a hollow rotating cylinder rotatably connected to the support frame, and a drive motor fixed on the support frame. The hollow rotating cylinder includes an upper cylinder and a lower cylinder fixedly connected. A driven gear is fixed on the rotating shaft at the top of the upper cylinder, and a driving gear on the output shaft of the drive motor meshes with the driven gear. An adjustable nozzle is installed in the nozzle mounting chamber on the inner wall of the upper cylinder. A waste outlet is opened on the side wall of the lower cylinder, and a scraper is fixed at the bottom of the lower cylinder. The layered compaction mechanism includes a compaction ring fixed to the bottom of the lower cylinder and telescopic pressure heads distributed along the circumference of the compaction ring; the telescopic pressure head includes a hydraulic cylinder body fixed radially on the compaction ring and a compaction head installed at the front end of the piston rod of the hydraulic cylinder body; The sensor system includes a pressure sensor mounted on the telescopic pressure head, a compaction sensor mounted on the compaction ring, a temperature sensor, a humidity sensor, and a borehole wall pressure sensor. The control system includes a data acquisition unit, a PLC controller, and a hydraulic control valve group. The data acquisition unit is electrically connected to each sensor to acquire detection signals. The PLC controller is electrically connected to the data acquisition unit, the hydraulic drive cylinder, the drive motor, the control valve of the adjustable nozzle, and the hydraulic control valve group. The PLC controller has a built-in extended Kalman filter algorithm module for multi-sensor data fusion and a built-in multi-parameter coupled pressure force calculation module for calculating the target pressure force. The hydraulic control valve group is connected to each hydraulic cylinder to control the movement of the telescopic pressure head.

7. The progressive hole protection device based on layered compaction according to claim 6, characterized in that: The rotating shaft is located at the center of the top of the upper cylinder and is mounted on the support frame via a bearing seat; the nozzle mounting chambers are distributed along the circumference of the upper cylinder, and the spray direction of the adjustable nozzles is downward; the waste outlet is distributed along the circumference of the lower cylinder and extends axially to form a strip-shaped opening; the scraper is distributed along the circumference of the lower cylinder and extends radially outward.

8. The progressive hole protection device based on layered compaction according to claim 6, characterized in that: The pressure sensor is installed between the hydraulic cylinder and the compaction head, and its signal output terminal is electrically connected to the signal input terminal of the data acquisition unit; the density sensor is installed on the compaction ring between adjacent telescopic pressure heads, with the probe facing the borehole wall; the temperature sensor, humidity sensor and borehole wall pressure sensor are all installed on the compaction ring, and the signal output terminals of each sensor are electrically connected to the data acquisition unit.

9. The progressive hole protection device based on layered compaction according to claim 6, characterized in that: The data input terminal of the PLC controller is electrically connected to the data output terminal of the data acquisition unit to receive sensor data before fusion; the control output terminal of the PLC controller is electrically connected to the solenoid valve of the hydraulic drive cylinder, the driver of the drive motor, the control valve of the adjustable nozzle, and the hydraulic control valve group respectively; the hydraulic control valve group is a multi-proportional valve group, which is connected to each hydraulic cylinder through hydraulic pipelines.

10. The progressive hole protection device based on layered compaction according to claim 6, characterized in that: The telescopic pressure heads are distributed at equal angles along the circumference of the compaction ring; the rear end of the cylinder body of the hydraulic cylinder is fixed on the compaction ring; the working surface of the compaction head is an arc-shaped surface that matches the inner wall of the borehole.

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