A low-clearance large-diameter inclined pile hole-forming device and hole-forming quality control method

Abstract

The application provides a low-clearance large-diameter inclined pile hole forming equipment and a hole forming quality control method, and belongs to the technical field of inclined pile hole forming.The hole forming equipment comprises a body, a power head, a sliding cross beam saddle, drilling tools and a control assembly.The body comprises a chassis, a drilling frame and an open door sealing frame.The drilling frame and the chassis form an angle alpha, which is adjusted in cooperation with the intersection angle beta of the upper and lower frames of the chassis to form a composite angle compensation mechanism, so that the drilling angle of the drilling machine can be flexibly adjusted in a limited space, and the drilling machine can flexibly adapt to different inclination pile foundation construction requirements.The hole forming quality control method comprises the following steps: preparation before construction, setting drilling parameters, real-time monitoring, dynamic deviation correction, mud circulation and residue discharge, and inspection and acceptance after construction.A deviation correction decision system based on machine learning is established, deviation correction parameter combinations are generated in combination with the degree of deviation of the hole slope from the set threshold, the deviation correction efficiency and accuracy are improved, the influence of geological conditions on the drilling accuracy is reduced, and the drilling slope consistency is ensured.

Description

Technical Field

[0001] This invention relates to the field of inclined pile drilling technology, and more specifically, to a drilling equipment and a drilling quality control method for low-clearance, large-diameter inclined piles. Background Technology

[0002] In foundation engineering, inclined pile construction has significant application value, especially in areas with complex terrain or limited space. However, the construction of large-diameter inclined piles with low clearance presents numerous challenges. Existing inclined pile drilling equipment often uses a rigid, integral structure for the drilling frame, which cannot achieve large-angle (>15°) inclined hole construction under limited height conditions. Furthermore, angle adjustment relies on the relocation of the entire equipment, making angle adjustment difficult, and the structure is bulky and cannot flexibly adapt to the requirements of pile foundations with different inclinations, resulting in low construction efficiency. In addition, there is a lack of real-time control of the hole inclination during the drilling process. Traditional drilling methods cannot guarantee a consistent hole inclination, which can easily lead to excessive hole inclination deviation, affecting the quality and bearing capacity of the pile foundation.

[0003] Given the above technical deficiencies, there is an urgent need to design a drilling equipment and a drilling quality control method for low-clearance, large-diameter inclined piles to solve the existing technical bottlenecks. Summary of the Invention

[0004] The purpose of this invention is to provide a drilling equipment and a drilling quality control method for low-clearance, large-diameter inclined piles, thereby solving the above-mentioned technical problems.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A drilling device for large-diameter inclined piles with low headroom includes a main body, a power head, a sliding crossbeam saddle, drilling tools, and control components.

[0007] The main body includes a chassis, a drill frame, and an opening and sealing frame. The chassis is installed on the ground in the area to be drilled. The drill frame is hinged to the working surface of the chassis. The drill frame is driven to rotate relative to the chassis by a slanted support cylinder electrically connected to the control component. The axis of the drill frame forms an angle α with the working surface of the chassis. One end of the slanted support cylinder is hinged to the working surface of the chassis, and the other end is hinged to the side wall of the drill frame. The drill frame is provided with a slide rail. The sliding crossbeam saddle is slidably installed on the slide rail. The sliding crossbeam saddle is driven to move up and down along the slide rail by a hydraulic cylinder electrically connected to the control component. The opening and sealing frame is installed on the chassis to restrict the horizontal movement of the drill bit.

[0008] The power head is suspended from the sliding beam saddle by a lifting lug. A first hydraulic cylinder is provided between the power head and the sliding beam saddle. One end of the first hydraulic cylinder is hinged to the power head and the other end is hinged to the sliding beam saddle. The first hydraulic cylinder drives the power head to rotate relative to the sliding beam saddle. The power head includes a power source, a transmission mechanism, and a spindle. The power source drives the spindle to rotate through the transmission mechanism. The output end of the spindle is connected to the drill bit, and a pressure gauge is provided at the connection. The transmission mechanism includes a planetary reducer and a single-stage closed gear. The planetary reducer and the single-stage closed gear are sequentially arranged between the power source and the spindle.

[0009] The drilling tool is provided with a reducing connector, a drill rod and a drill bit in sequence along the power output direction, and the reducing connector is snapped onto the door sealing frame.

[0010] According to a preferred embodiment of the present invention, the drill frame is a portal frame structure, which includes two columns and several crossbeams. The two columns are respectively installed on opposite sides of the working surface of the chassis. Each column is connected to the bearing seat of the working surface of the chassis via two connecting shafts. Each column is provided with a slide rail. The sliding crossbeam is saddle-mounted on the two slide rails. Two inclined support cylinders are provided, which are respectively used to support the two columns. The angle α between the drill frame and the chassis is 0° to 30°. The working surface of the chassis is provided with four or more lifting points for hoisting.

[0011] According to a preferred embodiment of the present invention, the chassis includes an upper frame and a lower frame disposed below the upper frame. The top surface of the upper frame forms the working surface of the chassis. The lower frame is placed horizontally on the ground in the area to be drilled. One side of the upper frame is hinged to one side of the lower frame to form an angle β. A support rod for fixing the angle β is provided on the opposite side of the hinge. One end of the support rod is fixed to the lower surface of the upper frame and the other end is fixed to the upper surface of the lower frame. The door opening and sealing frame is installed on the upper frame.

[0012] According to the preferred technical solution of the present invention, the door sealing frame is a hydraulic cylinder-supported opening and closing type, which is powered by four second hydraulic cylinders. The sliding crossbeam saddle moves up and down along the slide rail by a distance of 4500mm. There are two hydraulic cylinders with synchronized mechanical rigidity.

[0013] According to a preferred embodiment of the present invention, the power head further includes a central pipe and an air inlet pipe. The central pipe is provided with a load-bearing bearing, an anti-jump bearing, and a liner for slag discharge. The input end of the air inlet pipe is connected to a first air pipe provided on the drill frame, and the output end is connected to a second air pipe provided on the drill bit. The first air pipe is provided with an air distribution ring for supplying compressed air, and a shut-off valve is provided at the connection between the second air pipe and the air inlet pipe.

[0014] According to a preferred embodiment of the present invention, the drill bit is connected to the output end of the spindle via a flange structure, and the drill bit is also provided with a drill bit stabilizer and a drill pipe stabilizer.

[0015] The present invention provides a method for controlling the drilling quality of large-diameter inclined piles with low clearance, comprising the following steps:

[0016] S1. Pre-construction preparation: Level the ground in the area to be drilled, place the drilling equipment at the drilling point, adjust the angle β between the upper frame and the lower frame and the angle α between the drill frame and the chassis to the construction requirements, and calibrate the initial posture of the drilling equipment and the initial position and initial slope of the drill bit using a total station.

[0017] S2. Set drilling parameters: The drilling parameters include drilling pressure and drilling speed;

[0018] S3. Real-time monitoring: The fiber optic grating array embedded in the drill rod stabilizer is used to monitor the bending strain distribution of the drill rod in real time. Segmented drilling is adopted, with each segment being 5 to 10 meters long. After each segment is drilled and the hole is formed, the borehole is measured in real time to record the borehole inclination and borehole azimuth, calculate the bottom elevation of the hole and the borehole trajectory, and predict the development trend of borehole inclination.

[0019] S4. Dynamic correction: Collect historical correction data to establish a database, train intelligent algorithms, and establish a machine learning-based correction decision system. When the borehole slope exceeds a set threshold, the correction program is started. The correction decision system automatically generates a combination of correction parameters. The correction program includes adjusting the drilling pressure, adjusting the drilling speed, and adjusting the angle α between the drill frame and the chassis.

[0020] S5. Slurry circulation and slag removal: Slag removal is carried out by air lift reverse circulation method;

[0021] S6. Post-construction inspection and acceptance: After drilling is completed, the borehole inclination, diameter and depth are comprehensively tested using the borehole wall detection method based on acoustic imaging. Only after all indicators meet the requirements can the next step of steel cage installation and concrete pouring be carried out.

[0022] In a preferred embodiment of the present invention, the deviation of the borehole inclination from the set threshold is caused by the coupling effect of the drilling pressure and the drilling rate; therefore, the borehole inclination satisfies the following relationship:

[0023]

[0024] In the formula, T is the drilling pressure, in kN; k1 is the actual hole inclination, dimensionless; k2 is the designed hole inclination, dimensionless; K1 is the drilling pressure sensitivity coefficient, determined through calibration tests; K2 is the drilling rate sensitivity coefficient, determined through mud rheology tests and CFD simulation analysis; v is the drilling rate, in m / s; L is the current drilling depth, in mm; μ is the friction coefficient between the drill bit and the formation, dimensionless; C d ρ is the hydrodynamic coefficient, dimensionless; ρ is the mud density, in kg / m³. 3 A represents the lateral projected area of ​​the drill bit, in meters. 2 θ is the instantaneous angle between the actual hole axis and the designed hole axis; m is the mass of the drill bit, in kg.

[0025] In the preferred embodiment of the present invention, the combination of correction parameters in step S4 satisfies the following optimization model:

[0026] ΔT = a1(k1-k2) + a2(dk / dt);

[0027] Δv = a3(k1-k2) + a4(dk / dt);

[0028] Δα=a5(k1-k2)+a6(dk / dt);

[0029] In the formula, ΔT is the drilling pressure adjustment amount, in kN; Δv is the drilling speed adjustment amount, in m / s; Δα is the drill frame angle adjustment amount, in °; k1 is the actual hole inclination; k2 is the designed hole inclination; dk / dt is the hole inclination change rate; a1~a6 are control coefficients;

[0030] The control coefficients a1 to a6 satisfy an adaptive update relationship:

[0031] a i =a i _base×exp(-λ i ×Δt)

[0032] In the formula, a i _base is the basic control coefficient; λ i Δt is the time decay coefficient, i = 1, 2, ..., 6; Δt is the correction duration.

[0033] According to the preferred technical solution of the present invention, step S5 further includes real-time monitoring of the specific gravity and viscosity of the mud, and dynamically adjusting the rheological parameters of the mud in combination with drilling depth and borehole inclination data to optimize the air lift reverse circulation slag removal efficiency. The adjustment of the specific gravity and viscosity of the mud satisfies the following relationship:

[0034] Mud specific gravity adjustment formula:

[0035]

[0036] Mud viscosity adjustment formula:

[0037]

[0038] In the formula, ρ new ρ is the adjusted specific gravity of the mud. old ξ represents the original mud density. new To adjust the mud viscosity, ξ old Where L is the original mud viscosity, L is the current drilling depth, L' is the design depth, k1 is the actual borehole inclination, k2 is the design borehole inclination, and b1, b2, b3, b4, b5, and b6 are adjustment coefficients.

[0039] In summary, compared with the prior art, the beneficial effects of the present invention are:

[0040] In the drilling equipment for large-diameter inclined piles with low headroom of this invention, the drill frame and chassis are hinged by double inclined hydraulic cylinders. Combined with the adjustment of the angle β between the upper and lower frames of the chassis, a composite angle compensation mechanism is formed, breaking through the angle limitations under low headroom conditions. This allows the drilling rig to flexibly adjust the drilling angle within a limited space, adapting to the construction requirements of pile foundations with different inclinations, thus improving the applicability and flexibility of the equipment. Furthermore, the planetary reducer and the single-stage closed gear form a two-stage torque transmission chain, whose radial load-bearing capacity is 3.2 times higher than that of traditional open gears. Especially in hard rock formations or large-diameter drilling, the high torque ensures that the drill bit has sufficient cutting force, enabling the equipment to withstand greater lateral loads and impacts, improving drilling efficiency, and effectively reducing equipment failures and damage. A pressure gauge is integrated at the drill flange connection to monitor axial load in real time. The door sealing frame, combined with the drill bit stabilizer and drill rod stabilizer, forms a three-point centering structure. By precisely controlling the sway, the lateral pressure on the drill bit and drill rod during drilling is reduced, decreasing equipment wear and extending the equipment's service life.

[0041] The present invention provides a method for controlling the drilling quality of large-diameter inclined piles with low clearance. It establishes a quantitative control model for drilling pressure and speed, considering the influence of friction coefficient and borehole inclination angle, making parameter control more consistent with actual working conditions. The relationships between parameters are clear, facilitating on-site operation and control. By embedding a fiber optic grating array within the drill rod stabilizer to monitor the bending strain distribution of the drill rod in real time and acquiring real-time data such as borehole inclination and bottom elevation, a machine learning-based correction decision system is established based on historical correction data. This system generates correction parameter combinations based on the degree of borehole inclination deviation from a set threshold, improving correction efficiency and accuracy. Through real-time monitoring and dynamic adjustment, the equipment can better adapt to complex geological conditions, optimizing and adjusting according to specific conditions. Precise control of the borehole inclination reduces the impact of geological conditions on drilling accuracy, improving the adaptability and reliability of the equipment. Furthermore, the adaptively updated control coefficients of the correction parameter combinations can be dynamically adjusted according to the correction duration, optimizing the correction parameters in real time based on actual construction conditions, further improving the correction effect, ensuring consistent borehole inclination, and reducing borehole inclination deviation. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of a drilling device for a low-clearance, large-diameter inclined pile according to the present invention.

[0043] Figure 2 This is a schematic diagram of the main body of the present invention;

[0044] Figure 3 This is a schematic diagram of the power head of the present invention;

[0045] Figure 4 This is a flowchart of a method for controlling the drilling quality of a large-diameter inclined pile with low clearance according to the present invention;

[0046] In the diagram, 1-body, 11-chassis, 111-shaft seat, 112-upper frame, 113-lower frame, 114-support rod, 12-drill frame, 121-column, 122-crossbeam, 123-connecting shaft, 13-door opening and sealing frame, 14-slanted brace cylinder, 2-power head, 21-center tube, 22-air inlet pipe, 3-sliding crossbeam saddle. Detailed Implementation

[0047] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for illustration and explanation only and are not intended to limit the present invention.

[0048] like Figures 1 to 3 As shown, a drilling device for a large-diameter inclined pile with low clearance includes a body 1, a power head 2, a sliding crossbeam saddle 3, a drilling tool (not shown in the figure), and a control component (not shown in the figure).

[0049] The main body 1 includes a chassis 11, a drill frame 12, and an opening and sealing frame 13. The chassis 11 is installed on the ground in the area to be drilled. The drill frame 12 is hinged to the working surface of the chassis 11. The drill frame 12 is driven to rotate relative to the chassis 11 by a slanted support cylinder 14 electrically connected to the control component. The axis of the drill frame 12 forms an angle α with the working surface of the chassis 11. One end of the slanted support cylinder 14 is hinged to the working surface of the chassis 11, and the other end is hinged to the side wall of the drill frame 12. The drill frame 12 is provided with a slide rail (not shown in the figure). The sliding crossbeam saddle 3 is slidably installed on the slide rail. The sliding crossbeam saddle 3 is driven to move up and down along the slide rail by a hydraulic cylinder electrically connected to the control component. The opening and sealing frame 13 is installed on the chassis 11 to limit the horizontal movement of the drill bit.

[0050] The power head 2 is suspended from the sliding beam saddle 3 by a lifting lug. A first hydraulic cylinder (not shown in the figure) is provided between the power head 2 and the sliding beam saddle 3. One end of the first hydraulic cylinder is hinged to the power head 2 and the other end is hinged to the sliding beam saddle 3. The first hydraulic cylinder drives the power head 2 to rotate relative to the sliding beam saddle 3. The power head 2 includes a power source, a transmission mechanism and a spindle. The power source drives the spindle to rotate through the transmission mechanism. The output end of the spindle is connected to the drill bit, and a pressure gauge is provided at the connection. The transmission mechanism includes a planetary reducer and a single-stage closed gear. The planetary reducer and the single-stage closed gear are arranged sequentially between the power source and the spindle.

[0051] The drilling tool is provided with a reducing connector, drill rod and drill bit in sequence along the power output direction. The reducing connector is snapped onto the door sealing frame 13.

[0052] The drill frame 12 is hinged to the chassis 11 via double inclined support cylinders 14, forming an angle α (adjustable from 0° to 30°). Combined with the split design of the upper and lower frames 113 of the chassis 11 with an intersection angle β, a composite angle compensation mechanism is formed, which can achieve multi-dimensional angle compensation in low-clearance environments. Compared with the traditional integral drill frame 12, the space adaptability is improved by more than 60%, and the minimum construction clearance height can be reduced to less than 8m. This breaks through the angle limitation of traditional drilling rigs under low-clearance conditions, allowing the drilling rig to flexibly adjust the drilling angle in a limited space and flexibly adapt to the construction requirements of pile foundations with different inclinations. This is especially important for complex geological conditions and space-constrained construction environments. In addition, the power head 2 is suspended from the sliding crossbeam saddle 3 by the lifting lugs and is driven to rotate by the first cylinder, which can achieve a 50° rotation action, so as to facilitate the installation and disassembly of drilling tools and reduce construction difficulty.

[0053] The planetary reducer and the single-stage closed gear form a two-stage torque transmission chain to transmit power to the drill bit. Its radial load capacity is 3.2 times higher than that of the traditional open gear, and it can achieve stepless speed regulation. Especially when drilling in hard rock formations or large-diameter holes, the high torque can ensure that the drill bit has sufficient cutting force, enabling the equipment to withstand greater lateral loads and impact forces, thereby improving drilling efficiency. The high load capacity of the two-stage torque transmission chain enables the equipment to operate stably under these complex conditions, reducing equipment damage caused by changes in geological conditions.

[0054] In a preferred embodiment of the present invention, the drill frame 12 is a portal frame structure, which includes two columns 121 and several crossbeams 122. The two columns 121 are respectively installed on opposite sides of the working surface of the chassis 11. Each column 121 is connected to the bearing seat 111 of the working surface of the chassis 11 through two connecting shafts 123. Each column 121 is provided with a slide rail. The sliding crossbeam saddle 3 is slidably installed on the two slide rails. Two inclined support cylinders 14 are provided, which are respectively used to support the two columns 121. The angle α between the drill frame 12 and the chassis 11 is 0° to 30°. The working surface of the chassis 11 is provided with four or more lifting points for hoisting.

[0055] The drill frame 12 has a portal frame structure with good geometric stability, which can effectively distribute and bear the lateral forces and vertical loads from the drilling process, ensuring the stability of the drill frame 12 during the drilling process and reducing the risk of structural deformation and instability. Each column 121 is connected to the chassis 11 through two connecting shafts 123, which enhances the structural rigidity. The drill frame 12 and the chassis 11 are bidirectionally supported by inclined bracing cylinders 14. After removing one of the two connecting shafts 123 of the column 121, the drill frame 12 can tilt backward 0 to 30° relative to the chassis 11 under the drive of the two inclined bracing cylinders 14, which effectively reduces the labor intensity of workers and adapts to different construction needs. In addition, the chassis 11 and the drill frame 12 can also be designed to be detachable for convenient transportation.

[0056] In a preferred embodiment of the present invention, the chassis 11 includes an upper frame 112 and a lower frame 113 disposed below the upper frame 112. The top surface of the upper frame 112 forms the working surface of the chassis 11. The lower frame 113 is placed horizontally on the ground in the area to be drilled. One side of the upper frame 112 is hinged to one side of the lower frame 113 to form an angle β. A support rod 114 for fixing the angle β is provided on the opposite side of the hinge. One end of the support rod 114 is fixed to the lower surface of the upper frame 112 and the other end is fixed to the upper surface of the lower frame 113. The door opening and sealing frame 13 is installed on the upper frame 112.

[0057] As a preferred embodiment of the present invention, the door sealing frame 13 is a hydraulic cylinder-supported opening and closing type, which is powered by four second hydraulic cylinders. The sliding crossbeam saddle 3 moves up and down along the slide rail by a distance of 4500mm. There are two hydraulic cylinders with synchronized mechanical rigidity.

[0058] Two hydraulic cylinders mechanically and synchronously drive the sliding crossbeam saddle 3 to move up and down along the slide rail, ensuring that the sliding crossbeam saddle 3 maintains precise synchronous movement during the up and down movement, reducing the offset and vibration of the sliding crossbeam saddle 3, reducing the lateral pressure on the drill bit and drill rod during the drilling process, and further reducing the wear of the equipment.

[0059] In a preferred embodiment of the present invention, the power head 2 further includes a central pipe 21 and an air inlet pipe 22. The central pipe 21 is provided with a load-bearing bearing, an anti-jump bearing, and a liner for slag discharge. The input end of the air inlet pipe 22 is connected to a first air pipe provided on the drill frame 12, and the output end is connected to a second air pipe provided on the drill tool. The first air pipe is provided with an air distribution ring for supplying compressed air, and a shut-off valve is provided at the connection between the second air pipe and the air inlet pipe 22.

[0060] The air inlet pipe 22 and the liner of the central pipe 21 form an annular acceleration channel, creating a jet effect. Compressed air can pass through at a higher airflow velocity, thereby more effectively expelling rock cuttings and mud from the borehole during the drilling process. This significantly improves the efficiency of cuttings removal, enhances the airflow's ability to carry rock cuttings, reduces the risk of blockage in the borehole, ensures the continuity and stability of the drilling process, and improves construction efficiency. Load-bearing bearings and anti-jump bearings improve motion accuracy and operational smoothness.

[0061] In a preferred embodiment of the present invention, the drill bit is connected to the output end of the spindle via a flange structure, and the drill bit is also provided with a drill bit stabilizer and a drill pipe stabilizer.

[0062] The drill bit is clamped onto the door sealing frame 13 via a reducing connector to form the first stable point. Together with the drill rod stabilizer and drill bit stabilizer, it forms a three-point centering constraint, which significantly reduces the hole inclination deviation during the drilling process, ensures high accuracy of the drilling direction, effectively reduces the sway and vibration of the drill bit during the drilling process, reduces the lateral pressure on the drill bit and drill rod during the drilling process, reduces equipment wear, and extends the service life of the equipment.

[0063] like Figure 4 As shown, the present invention provides a method for controlling the drilling quality of large-diameter inclined piles with low clearance, comprising the following steps:

[0064] S1. Pre-construction preparation: Level the ground in the area to be drilled, place the drilling equipment at the drilling point, adjust the angle β between the upper frame 112 and the lower frame 113 and the angle α between the drill frame 12 and the chassis 11 to the construction requirements, and calibrate the initial attitude of the drilling equipment and the initial position and initial slope of the drill bit using a total station.

[0065] S2. Set drilling parameters: Drilling parameters include drilling pressure and drilling speed;

[0066] S3. Real-time monitoring: The fiber optic grating array embedded in the drill pipe stabilizer is used to monitor the bending strain distribution of the drill pipe in real time. Segmented drilling is adopted, with each segment being 5-10m. After each segment is drilled and the hole is formed, the borehole inclination is measured in real time to record the borehole inclination and borehole azimuth, calculate the bottom elevation of the hole and the drilling trajectory, and predict the development trend of borehole inclination.

[0067] S4. Dynamic correction: Collect historical correction data to establish a database, train intelligent algorithms, and establish a machine learning-based correction decision system. When the borehole slope exceeds the set threshold, the correction program is started. The correction decision system automatically generates a combination of correction parameters. The correction program includes adjusting drilling pressure, adjusting drilling speed, and adjusting the angle α between the drill frame 12 and the chassis 11.

[0068] Adjusting the drilling pressure specifically involves using a hydraulic system to reduce the lateral pressure on the drill bit, allowing it to return to its predetermined trajectory. Adjusting the drilling speed involves reducing the drilling speed, enabling the drill bit to correct its course at a lower feed rate. Adjusting the angle of the drill frame 12 involves fine-tuning the tilt angle of the drill frame 12 using the inclined support cylinder 14, ensuring the drilling direction meets design requirements. By embedding a fiber optic grating array within the drill rod stabilizer to monitor the bending strain distribution of the drill rod in real time and acquiring real-time data such as hole inclination and bottom elevation, a machine learning-based correction decision system is established based on historical correction data. This system generates a combination of correction parameters based on the degree to which the hole inclination deviates from a set threshold, reducing reliance on manual experience and improving the accuracy and efficiency of correction. Through real-time monitoring and dynamic adjustment, the equipment can better adapt to complex geological conditions, optimizing and adjusting according to specific conditions. By precisely controlling the hole inclination, the impact of geological conditions on drilling accuracy is reduced, improving the adaptability and reliability of the equipment.

[0069] S5. Slurry circulation and slag removal: Slag removal is carried out by air lift reverse circulation method;

[0070] In this embodiment, an air-lift reverse circulation slag removal method is used, and the circulating mud volume can reach 600m³. 3 / h, when drilling depth is within 50m, only the lower air compressor is needed; if the drilling depth is greater than 50m, an intermediate air compressor drill rod needs to be connected, and an air compressor with a capacity of 40m is required. 3 / min, wind pressure P = 0.7MPa or air volume 20m³ / min 3 / min, medium-pressure air compressor with air pressure P=1.2MPa; when starting drilling, air should be supplied first, then feed. During drilling, the drill bit should be depressurized and drilled. When the slag removal is interrupted, the drill bit should be lifted. When the slag is discharged, the drill bit should be slowly lowered. When stopping drilling, the drill bit should be lifted first, and then the air should be stopped.

[0071] S6. Post-construction inspection and acceptance: After drilling is completed, the borehole inclination, diameter and depth are comprehensively tested using the borehole wall detection method based on acoustic imaging. Only after all indicators meet the requirements can the next step of steel cage installation and concrete pouring be carried out.

[0072] In a preferred embodiment of the present invention, the deviation of the hole inclination from the set threshold is caused by the coupling effect of drilling pressure and drilling speed, therefore the hole inclination satisfies the following relationship:

[0073]

[0074] In the formula, T is the drilling pressure in kN; k1 is the actual hole inclination (dimensionless); k2 is the designed hole inclination (dimensionless); K1 is the drilling pressure sensitivity coefficient (dimensionless, determined through calibration tests); K2 is the drilling rate sensitivity coefficient (dimensionless, determined through mud rheology tests and CFD simulation analysis); v is the drilling rate in m / s; L is the current borehole depth in mm; μ is the friction coefficient between the drill bit and the formation (dimensionless); C d ρ is the hydrodynamic coefficient, dimensionless; ρ is the mud density, in kg / m³. 3 A represents the lateral projected area of ​​the drill bit, in meters. 2 θ is the instantaneous angle between the actual hole axis and the designed hole axis; m is the mass of the drilling tool, in kg.

[0075] By establishing a relationship between borehole inclination and drill pressure / speed, changes in borehole inclination can be accurately predicted, preventing it from exceeding design requirements. Based on real-time monitoring of drill pressure and speed data, drilling parameters are dynamically adjusted to ensure the borehole inclination remains within a set threshold. This significantly improves the controllability of the drilling process and reduces the risk of borehole inclination exceeding tolerances due to improper drill pressure or speed. The relationship includes the friction coefficient μ between the drill bit and the formation, mud density ρ, and hydrodynamic coefficient C. d These parameters reflect the influence of geological conditions on the drilling process. By adjusting these parameters, the equipment can better adapt to complex geological conditions, thus improving its adaptability and reliability under complex geological conditions.

[0076] In a preferred embodiment of the present invention, the combination of correction parameters in step S4 satisfies the following optimization model:

[0077] ΔT = a1(k1-k2) + a2(dk / dt);

[0078] Δv = a3(k1-k2) + a4(dk / dt);

[0079] Δα=a5(k1-k2)+a6(dk / dt);

[0080] In the formula, ΔT is the drilling pressure adjustment amount, in t; Δv is the drilling speed adjustment amount, in m / s; Δα is the drill frame angle adjustment amount, in °; k1 is the actual hole inclination; k2 is the designed hole inclination; dk / dt is the hole inclination change rate; a1~a6 are control coefficients;

[0081] The control coefficients a1 to a6 satisfy the adaptive update relationship:

[0082] a i =a i _base×exp(-λ i ×Δt)

[0083] In the formula, a i _base is the basic control coefficient; λ i Δt is the time decay coefficient, i = 1, 2, ..., 6; Δt is the correction duration.

[0084] The correction parameters (drill pressure, drilling speed, and drill frame 12-degree angle) are based on the deviation between the actual hole inclination and the designed hole inclination, as well as the rate of change of the hole inclination. The correction parameters can be precisely adjusted, which significantly improves the correction efficiency. The control coefficients a1 to a6 satisfy the adaptive update relationship and can be dynamically adjusted according to the correction duration. The correction parameters can be optimized in real time according to the actual construction situation, further improving the correction effect, ensuring consistent drilling inclination, and reducing hole inclination deviation.

[0085] In a preferred embodiment of the present invention, step S5 further includes real-time monitoring of the specific gravity and viscosity of the drilling mud, and dynamically adjusting the rheological parameters of the drilling mud in conjunction with borehole depth and borehole inclination data to optimize the air-lift reverse circulation slag removal efficiency. The adjustment of the specific gravity and viscosity of the drilling mud satisfies the following relationship:

[0086] Mud specific gravity adjustment formula:

[0087]

[0088] Mud viscosity adjustment formula:

[0089]

[0090] In the formula, ρ new ρ is the adjusted specific gravity of the mud. old ξ represents the original mud density. new To adjust the mud viscosity, ξ old Where L is the original mud viscosity, L is the current drilling depth, L' is the design depth, k1 is the actual borehole inclination, k2 is the design borehole inclination, and b1, b2, b3, b4, b5, and b6 are adjustment coefficients.

[0091] The dynamic adjustment mechanism ensures that the mud maintains optimal slag removal performance under different working conditions, provides better borehole wall stability, reduces the risk of borehole collapse, and optimizes mud parameters to reduce slag removal time, improve drilling efficiency, reduce downtime caused by poor slag removal, reduce lateral pressure on the drill bit and drill rod during drilling, strictly control the borehole inclination within the design range, reduce the risk of borehole inclination exceeding tolerance, and improve drilling quality.

[0092] It should be understood that the above embodiments are one or more embodiments of the present invention, and there are many other embodiments and variations based on the present invention; any variations and modifications made by those skilled in the art through the present invention without making pioneering innovations are all within the protection scope of the present invention.

Claims

1. A drilling device for large-diameter inclined piles with low clearance, characterized in that: Includes the main body, power head, sliding crossbeam saddle, drilling tools, and control components; The main body includes a chassis, a drill frame, and an opening and sealing frame. The chassis is installed on the ground in the area to be drilled. The drill frame is hinged to the working surface of the chassis. The drill frame is driven to rotate relative to the chassis by a slanted support cylinder electrically connected to the control component. The axis of the drill frame forms an angle α with the working surface of the chassis. One end of the slanted support cylinder is hinged to the working surface of the chassis, and the other end is hinged to the side wall of the drill frame. The drill frame is provided with a slide rail. The sliding crossbeam saddle is slidably installed on the slide rail. The sliding crossbeam saddle is driven to move up and down along the slide rail by a hydraulic cylinder electrically connected to the control component. The opening and sealing frame is installed on the chassis to restrict the horizontal movement of the drill bit. The power head is suspended from the sliding beam saddle by a lifting lug. A first hydraulic cylinder is provided between the power head and the sliding beam saddle. One end of the first hydraulic cylinder is hinged to the power head and the other end is hinged to the sliding beam saddle. The first hydraulic cylinder drives the power head to rotate relative to the sliding beam saddle. The power head includes a power source, a transmission mechanism, and a spindle. The power source drives the spindle to rotate through the transmission mechanism. The output end of the spindle is connected to the drill bit, and a pressure gauge is provided at the connection. The transmission mechanism includes a planetary reducer and a single-stage closed gear. The planetary reducer and the single-stage closed gear are sequentially arranged between the power source and the spindle. The drill string is provided with a reducing connector, drill rod and drill bit in sequence along the power output direction, and the reducing connector is snapped onto the door sealing frame; The chassis includes an upper frame and a lower frame located below the upper frame. The top surface of the upper frame forms the working surface of the chassis. The lower frame is placed horizontally on the ground in the area to be drilled. One side of the upper frame is hinged to one side of the lower frame to form an angle β. A support rod for fixing the angle β is provided on the opposite side of the hinge. One end of the support rod is fixed to the lower surface of the upper frame and the other end is fixed to the upper surface of the lower frame. The door opening and sealing frame is installed on the upper frame.

2. The drilling equipment for low-clearance, large-diameter inclined piles according to claim 1, characterized in that: The drill frame is a portal frame structure, which includes two columns and several crossbeams. The two columns are respectively installed on opposite sides of the working surface of the chassis. Each column is connected to the bearing seat of the working surface of the chassis via two connecting shafts. Each column is equipped with a slide rail. The sliding crossbeam is saddle-mounted on the two slide rails. Two inclined support cylinders are provided, which are used to support the two columns respectively. The drill frame forms an angle α with the chassis of 0° to 30°. The working surface of the chassis is provided with four or more lifting points for hoisting.

3. The drilling equipment for low-clearance, large-diameter inclined piles according to claim 1, characterized in that: The door opening and sealing frame is a hydraulic cylinder-supported opening and closing type, powered by four second hydraulic cylinders. The sliding crossbeam saddle moves up and down along the slide rail by a distance of 4500mm. There are two hydraulic cylinders with synchronized mechanical rigidity.

4. The drilling equipment for low-clearance, large-diameter inclined piles according to claim 1, characterized in that: The power head also includes a central pipe and an air inlet pipe. The central pipe is equipped with a load-bearing bearing, an anti-jump bearing, and a liner for slag discharge. The input end of the air inlet pipe is connected to a first air pipe on the drill frame, and the output end is connected to a second air pipe on the drill bit. The first air pipe is equipped with an air distribution ring for supplying compressed air, and a shut-off valve is provided at the connection between the second air pipe and the air inlet pipe.

5. The drilling equipment for low-clearance, large-diameter inclined piles according to claim 1, characterized in that: The drill bit is connected to the output end of the spindle via a flange structure, and the drill bit is also equipped with a drill bit stabilizer and a drill pipe stabilizer.

6. A method for controlling the drilling quality of large-diameter inclined piles with low clearance, used in the drilling equipment for large-diameter inclined piles with low clearance as described in claim 1, characterized in that... Includes the following steps: S1. Pre-construction preparation: Level the ground in the area to be drilled, place the drilling equipment at the drilling point, adjust the angle β between the upper frame and the lower frame and the angle α between the drill frame and the chassis to the construction requirements, and calibrate the initial posture of the drilling equipment and the initial position and initial slope of the drill bit using a total station. S2. Set drilling parameters: The drilling parameters include drilling pressure and drilling speed; S3. Real-time monitoring: The fiber optic grating array embedded in the drill rod stabilizer is used to monitor the bending strain distribution of the drill rod in real time. Segmented drilling is adopted, with each segment being 5 to 10 meters. After each segment is drilled and the hole is formed, the borehole is measured in real time to record the borehole inclination and borehole azimuth, calculate the bottom elevation of the hole and the borehole trajectory, and predict the development trend of borehole inclination. S4. Dynamic correction: Collect historical correction data to establish a database, train intelligent algorithms, and establish a machine learning-based correction decision system. When the borehole slope exceeds a set threshold, the correction program is started. The correction decision system automatically generates a combination of correction parameters. The correction program includes adjusting the drilling pressure, adjusting the drilling speed, and adjusting the angle α between the drill frame and the chassis. S5. Slurry circulation and slag removal: Slag removal is carried out by air lift reverse circulation method; S6. Post-construction inspection and acceptance: After drilling is completed, the borehole inclination, diameter and depth are comprehensively tested using the borehole wall detection method based on acoustic imaging. Only after all indicators meet the requirements can the next step of steel cage installation and concrete pouring be carried out.

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