Construction method of aeolian sand geological soft soil hardened mixing pile

Abstract

The invention relates to the technical field of cement mixing piles, in particular to an aeolian sand geology soft soil hardening mixing pile construction method, which comprises the following steps of: monitoring the drilling depth and torque change of a drill rod in real time, identifying the type of a soil layer and uploading information to a data acquisition unit through a stroke identification unit and a torque detection unit which are arranged on a pile machine; the drill rod is composed of a first drilling rod and a second drilling rod which are respectively connected with the driving unit, and the rotating direction and speed can be independently controlled so as to adapt to different soil layer characteristics. In the drilling process, the perpendicularity checking unit adjusts the perpendicularity of the drill rod in real time, and the construction precision is ensured. During guniting operation, graded guniting mixing operation is executed according to the type of a soil layer, the problem of uneven slurry distribution is solved by adjusting the rotating mode of the drill rod and the flow and pressure of slurry conveying and optimizing the mixing effect of the slurry and the soil layer, and the pile body strength and the composite foundation bearing capacity are improved.

Description

Technical Field

[0001] The invention relates to the technical field of cement mixing piles, and in particular to a construction method for hardened mixing piles in soft soil of aeolian sand geology. Background Art

[0002] Soft soil foundations often require effective reinforcement measures in engineering construction due to their low bearing capacity, high compressibility, and poor permeability. Traditional soft soil foundation treatment methods mainly include replacement and drainage consolidation methods, but these methods often have disadvantages such as long construction period, high cost, and great impact on the environment.

[0003] A pile mixer is a device that uses cement, lime and other curing agents to mix and reinforce soft soil in situ. This technology uses a special pile driver to spray the curing agent into the soft soil foundation, and through mechanical mixing, the curing agent and the soft soil are fully mixed, a series of physical and chemical reactions occur, and the soft soil is hardened into cement-reinforced soil with integrity, water stability and a certain strength.

[0004] In the prior art, during the drilling process of the pile driver, due to uneven geological changes, when the drill bit encounters an area where soft and hard soil bases are interlaced, the drill bit is prone to slipping at the junction of the two, thereby causing the construction pile driver to tilt and causing major accidents.

[0005] The Chinese patent application number 202111118239.5 discloses a construction method of a multi-mixing hard-breaking and crack-proof pile driver. The mud is mixed in layers through a variety of mixing methods to make the mud more uniform, so that no local harmful cracks will appear after the pile is formed, and the local collapse of the pile hole wall will be prevented; it can be made into a regular rectangular interface, so that the structure after the pile is formed will not shrink in diameter; the drilling and pile forming process is monitored by a microcomputer, which has certain intelligence and convenience, and can ensure the safety of construction; a retractable vibration hard-breaking device is installed on the top of the traditional drill bit to quickly crush hard rocks. This invention makes the mud more uniform, so that no local harmful cracks will appear after the pile is formed, and the local collapse of the pile hole wall will be prevented; it has certain intelligence and convenience.

[0006] Although patents similar to the above-mentioned technology effectively achieve rapid crushing of hard rocks by equipping the top of the drill bit with a retractable vibrating crushing device, significantly reducing the risk of the construction pile driver tilting due to hard soil, foundation reinforcement operations in the special geological environment of windy and soft soil still face multiple complex technical challenges.

[0007] The core feature of the sandy soft soil environment is that it contains abundant fine sand and silt. The bonding strength formed by the interaction between these granular materials is extremely low, causing the soil to exhibit significant flow characteristics. When carrying out cement mixing pile construction under such geological background, it is very easy to encounter the problem of pile driver sinking, which will further cause the deviation of the drilling rig's drill shaft, making it particularly difficult to maintain the vertical state of the drilling rig's drill shaft, and ultimately have an adverse impact on the quality control and smooth implementation of cement mixing pile construction.

[0008] In addition, the geological characteristics of the sandy areas, especially the looseness and high permeability of the sand, have a profound impact on the fluidity and permeability of the slurry. Specifically, the slurry tends to diffuse and drain rapidly in the highly permeable sand layer, resulting in a decrease in the slurry concentration in the area, forming the so-called "slurry-poor zone". On the contrary, in the dense soil layer, the slurry may accumulate due to the obstruction of permeability, forming a "slurry-rich zone". This uneven distribution of slurry further leads to differences in pile strength, which in turn affects the overall bearing capacity stability of the composite foundation, becoming a key issue that needs to be urgently solved in the reinforcement of sandy soft soil foundations.

[0009] Therefore, in view of the above problems, it is necessary to provide a method for constructing soft soil hardening mixing piles in aeolian sand geology to solve the above technical problems. Summary of the invention

[0010] The object of the present invention is to provide a method for constructing soft soil hardening mixing piles in aeolian sand geology to solve the technical problems raised in the above-mentioned background technology.

[0011] To achieve the above object, the present invention provides the following technical solutions: A method for constructing soft soil hardened mixing piles in aeolian sand geology, the method comprising the following steps: S1. The pile driver moves to the right position, the traction device lowers the drill rod, and the drive unit drives the drill rod to perform the pile drilling process; S2, identifying the soil layer where the current drill rod is located through the stroke identification unit and the torque detection unit, and transmitting the identified soil layer information to the data acquisition unit; S3, real-time detection and adjustment of the verticality of the drill pipe through the verticality verification unit; S4, judging whether the drilling depth of the drill rod is in place through the stroke identification unit, if it is in place, entering S5, if not, returning to S2 and continuing the drilling operation; S5. According to the soil layer information collected by the data acquisition unit, the drill rod performs lifting and shotcreting operations.

[0012] Preferably, the S2 soil layer identification comprises the following steps: S201, collecting drilling depth data of the drill rod through a stroke identification unit, and collecting torque data of the drill rod through a torque detection unit; S202, during the drilling process of the drill rod, determine whether the torque change of the drill rod exceeds a first threshold; if it does not exceed the first threshold, mark the current soil layer as a soft soil layer and upload the soil layer information to the data acquisition unit; if it exceeds the first threshold, enter S203; S203, determine whether the torque change of the drill rod exceeds the second threshold; if the value exceeds the first threshold but is less than the second threshold, mark the current soil layer as a hard soil layer and upload the soil layer information to the data acquisition unit; if it exceeds the second threshold, mark the current soil layer as a gravel layer and upload the soil layer information to the data acquisition unit.

[0013] Preferably, the verticality check of the S3 drill pipe comprises the following steps: S301, constructing a horizontal reference plane by means of a horizontal calibration unit arranged at the bottom of the pile driver; S302, judging whether the bottom of the pile driver is in a horizontal state during the drilling process of the drill rod, if it is in a horizontal state, the drilling state is maintained, if it is in a non-horizontal state, the process proceeds to S303; S303, determine whether the deflection angle of the bottom surface of the pile driver exceeds the preset value. If it exceeds the preset value, suspend the drilling operation and control the traction device to lift the drill rod; if it does not exceed the preset value, adjust the bottom surface of the pile driver by adjusting the support leg balance unit, and return to S302. At the same time, mark the soil layer where the drill rod is currently located as a deflected layer, and upload the soil layer information to the data acquisition unit.

[0014] Preferably, the S5 lifting and spraying operation comprises the following steps: S501, after the drill rod is drilled into place, the traction device lifts the drill rod and starts the spraying unit at the same time; S502, during the process of lifting the drill rod, the soil layer where the drill rod is located is judged and identified according to the stroke identification unit and the data acquisition unit; S503, the shotcrete unit performs corresponding shotcrete operations according to the type of soil layer where the drill rod is currently located.

[0015] Preferably, if the soil layer where the drill rod is currently located is a soft soil layer, a first-level shotcreting operation is performed; if the soil layer where the drill rod is currently located is a hard soil layer, a second-level shotcreting operation is performed; if the soil layer where the drill rod is currently located is a gravel layer, a third-level shotcreting operation is performed.

[0016] Preferably, if the soil layer where the drill rod is currently located is a deflected layer, a fourth-level shotcreting operation is performed.

[0017] Preferably, the stroke identification unit comprises an induction disk arranged on the traction device, on which an array of induction blocks is arranged, and on the outer side of the induction disk is a collecting piece for identifying the induction blocks, and the collecting piece obtains the lifting speed and lifting stroke of the drill rod by collecting the number of induction blocks passing through per unit time.

[0018] Preferably, the drill rod comprises a first drilling rod and a second drilling rod, the first drilling rod and the second drilling rod are socketed with each other, and the first drilling rod and the second drilling rod are respectively connected to a driving unit so that the rotation of the first drilling rod and the second drilling rod can be individually controlled.

[0019] Preferably, the level verification unit comprises a digital electronic level distributed in an array on the pile driver.

[0020] Preferably, the torque detection unit comprises a torque sensor arranged at an output end of the driving unit.

[0021] Technical effects and advantages of the present invention: 1. The present invention can monitor the lifting speed, stroke and torque change of the drill rod in real time through the stroke identification unit and the torque detection unit in combination with the numerical analysis unit of the controller, so as to accurately judge the type of soil layer (soft soil layer, hard soil layer, gravel layer, etc.) where the drill rod is located, and upload it to the data acquisition unit, which provides a scientific basis for subsequent construction operations, avoids blind construction, and improves the pertinence and effectiveness of construction.

[0022] 2. The present invention adjusts the rotation direction and speed of the drill rod in real time according to the collected soil layer information. In the hard soil layer, the drill rods rotate in the same direction to reduce resistance; in the gravel layer, the drill rods rotate alternately in opposite directions to avoid jamming, which effectively improves the penetration ability and construction efficiency of the drill rod, while reducing the risk of equipment damage.

[0023] 3. The present invention can detect and adjust the verticality of the drill rod in real time through the verticality verification unit and the horizontal verification unit, combined with the three-dimensional monitoring network of the electronic level. Under the geological conditions of aeolian sand, even if the pile driver deflects, it can be corrected in time through the support leg balance unit to ensure that the drill rod is always in a vertical state, thereby ensuring the construction quality and avoiding pile quality problems caused by deflection.

[0024] 4. The present invention uses a grouting unit to perform grouting operations at different levels according to the soil layer type and the drill rod deflection state. In the gravel layer, high-speed reverse alternating rotation and large flow rate and high-pressure grouting are adopted to ensure that the slurry and gravel are fully mixed. In the hard soil layer, reverse rotation and medium flow rate and medium pressure grouting are adopted to prevent the formation of slurry-poor areas. In the soft soil layer, low-speed co-directional rotation and medium flow rate and low pressure grouting are adopted to avoid slurry loss. This graded grouting method effectively solves the problem of uneven slurry distribution, improves the uniformity of pile strength, and enhances the overall bearing capacity of the composite foundation.

[0025] 5. When the drill rod is deflected, the present invention adopts a three-level response mechanism and takes different response measures according to the degree of deflection; continuous monitoring is performed when there is a slight deflection, drilling is suspended and equipment is adjusted when there is a moderate deflection, and emergency braking and lifting of the drill rod are performed when there is a serious deflection. This intelligent response mechanism can effectively avoid equipment damage and construction accidents caused by excessive deflection, thereby improving the safety and reliability of construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the main flow of the construction method of the present invention; Figure 2 It is a schematic diagram of the process of soil layer identification of the present invention; Figure 3 It is a schematic diagram of the process of checking the verticality of a drill pipe according to the present invention; Figure 4 It is a schematic diagram of the process of lifting shotcrete operation of the present invention; Figure 5 It is a schematic diagram of the main structure of the pile driver of the present invention; Figure 6 It is a front view of the traction unit of the present invention; Figure 7 It is a left side view of the traction unit of the present invention; Figure 8 It is a structural schematic diagram of the drill rod of the present invention.

[0027] The accompanying drawings are marked as follows: 1. Frame; 2. Traction device; 201. Fixed pulley; 202. Traction rope; 203. Reeling part; 3. Driving unit; 4. Drill rod; 401. first drilling rod; 402. second drilling rod; 5. Leg balancing unit; 6. Shotcrete device; 601. Shotcrete pump; 602. Grouting pipe; 7. Bracket; 8. Stroke recognition unit; 801. Induction disk; 802. Induction block; 803. Collection component. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1

[0030] Reference Figures 5 to 8 As shown, the pile driver includes a frame 1, and a leg balancing unit 5 is provided on the periphery of the frame 1 for adjusting the horizontal plane of the pile driver; a bracket 7 is provided at the end of the frame 1, a drill rod 4 is provided on the outside of the bracket 7, a driving part 3 is provided at the end of the drill rod 4, and a driving unit is provided inside the driving part 3 for driving the drill rod 4 to rotate; a traction device 2 is provided on the top of the driving part 3 for driving the drill rod 4 to perform lifting operations on the outside of the bracket 7.

[0031] The traction device 2 includes a fixed pulley 201 rotatably arranged on the bracket 7, and a traction rope 202 is arranged on the outer side of the fixed pulley 201. One end of the traction rope 202 is connected to the driving part 3, and the other end is connected to the winding part 203 arranged on the frame 1. The controller controls the rotation direction of the winding part 203 to make the driving part 3 slide on the outer side of the bracket 7.

[0032] The frame 1 is provided with a grouting device 6, which includes a grouting pump 601, which is connected to the drill rod 4 through a grouting pipe 602. The grouting pump 601 sprays slurry from the bottom of the drill rod 4 through the grouting pipe 602; the above-mentioned related components belong to the prior art and will not be described in detail here.

[0033] Reference Figures 1 to 8 As shown, the present invention proposes a construction method for aerodynamic sand geological soft soil hardening mixing piles, and the construction method comprises the following steps: S1, the pile driver travels to the position, the traction device 2 lowers the drill rod 4, and the driving unit drives the drill rod 4 to perform the pile drilling process.

[0034] S2. Identify the current soil layer through the stroke identification unit 8 and the torque detection unit, and transmit the soil layer information to the data acquisition unit.

[0035] The stroke identification unit 8 includes a sensing disk 801 arranged on the traction device 2, on which are arranged sensing blocks 802 distributed in an array, and a collecting component for identifying the sensing blocks 802 is arranged on the outer side of the sensing disk 801. The collecting component can obtain the lifting speed and lifting stroke of the drill rod 4 by collecting the number of sensing blocks 802 passing through per unit time.

[0036] When the winding part 203 drives the driving part 3 to slide outside the bracket 7, the fixed pulley 201 is pressed and rotated, and the induction block 802 on the induction disk 801 is synchronously driven to rotate. By detecting the number of induction blocks 802 passing through the collection part per unit time, the downward speed and stroke of the drill rod 4 can be obtained. Each induction block 802 has a different signal identifier. By analyzing the signal identifiers collected by the collection part, the downward stroke of the drill rod 4 can be accurately determined to avoid stroke confusion.

[0037] The torque detection unit includes a torque sensor provided on the driving unit.

[0038] The driving unit comprises a driving motor, and an output shaft of the driving motor is drivingly connected to the drill rod 4 .

[0039] S201 . Collect drilling depth data of the drill rod 4 through the stroke identification unit 8 , and collect torque data of the drill rod 4 through the torque detection unit.

[0040] S202, during the drilling process of the drill rod 4, determine whether the torque change of the drill rod 4 exceeds the first threshold; if it does not exceed the first threshold, mark the current soil layer as a soft soil layer and upload the soil layer information to the data acquisition unit; if it exceeds the first threshold, enter S203.

[0041] S203, determine whether the torque change of the drill rod 4 exceeds the second threshold; if the value exceeds the first threshold but is less than the second threshold, mark the current soil layer as a hard soil layer and upload the soil layer information to the data acquisition unit; if it exceeds the second threshold, mark the current soil layer as a gravel layer and upload the soil layer information to the data acquisition unit.

[0042] S3. Use the verticality checking unit to detect and adjust the verticality of the drill rod 4 in real time.

[0043] S4. Determine whether the drilling depth of the drill rod 4 is in place by the stroke identification unit 8. If it is in place, enter S5. If it is not in place, return to S2 and continue the drilling operation.

[0044] S5. According to the soil layer information collected by the data acquisition unit, the drill rod 4 performs the lifting and spraying operation.

[0045] The drill rod 4 includes a first drilling rod 401 and a second drilling rod 402, which are sleeved with each other and are respectively connected to a driving unit so that the rotation of the first drilling rod 401 and the second drilling rod 402 can be controlled separately.

[0046] When in use, the pile driver travels to the piling position, the legs on the frame 1 are lowered to make the pile driver in a horizontal state, and then the traction device 2 is controlled to lower the driving part 3 to move the drill rod 4 downward, and at the same time, the driving unit in the driving part 3 is controlled to start, and the driving unit drives the first drilling rod 401 and the second drilling rod 402 to rotate in opposite directions (for example, the first drilling rod 401 rotates clockwise, and the second drilling rod 402 rotates counterclockwise).

[0047] During the drilling process of the drill rod 4, the torque of the drill rod 4 increases slowly with the increase of the drilling depth. The numerical analysis unit of the controller can obtain the specific information of the soil layer where the drill rod 4 is currently located by real-time analysis of the data of the torque detection unit and the stroke speed detection unit.

[0048] If the numerical analysis unit detects that the torque change of the drill rod 4 does not exceed the first threshold value during the drilling process (that is, the torque increase per unit depth is in a stable state), it indicates that the drill rod 4 encounters little resistance during the drilling process. At this time, the numerical analysis unit marks the current soil layer as a soft soil layer and uploads the soil layer information to the data acquisition unit.

[0049] If the numerical analysis unit detects that the torque change of the drill rod 4 exceeds the first threshold but is less than the second threshold (that is, the torque increase per unit depth is beyond the stable state) during the drilling process, it indicates that the drill rod 4 is subjected to large resistance during the drilling process. At this time, the numerical analysis unit marks the current soil layer as a hard soil layer and uploads the soil layer information to the data acquisition unit; at the same time, the controller controls the first drilling rod 401 and the second drilling rod 402 to rotate in the same direction to reduce the superposition of reverse resistance and enhance the coordinated penetration ability of the drill rod 4.

[0050] If the numerical analysis unit detects that the torque change of the drill rod 4 exceeds the second threshold value during the drilling process (that is, the increase in torque per unit depth is beyond the stable state), it indicates that the drill rod 4 is subjected to large resistance during the drilling process. At this time, the numerical analysis unit marks the current soil layer as a gravel layer and uploads the soil layer information to the data acquisition unit; at the same time, the controller controls the first drilling rod 401 and the second drilling rod 402 to rotate alternately in the opposite direction through the driving unit to avoid gravel jamming and locking of the drill rod 4.

[0051] During the drilling process of the drill rod 4, the stroke identification unit 8 determines whether the drilling depth of the drill rod 4 is in place. If it is in place, the process goes to S5, and the drill rod 4 performs the lifting and spraying operation according to the soil layer information collected by the data acquisition unit. If it is not in place, the process returns to S2 and continues the drilling operation.

[0052] Embodiment 2

[0053] Although the above embodiment can identify different soil layer information during the drilling process of the drill rod 4, and change the drilling state accordingly according to the different soil layer information, when carrying out the mixing pile construction in the sandy soft soil environment, due to the significant flow characteristics of the soil, it is very easy to encounter the problem of pile driver sinking, which further causes the drilling rig's drill shaft to deviate, making it difficult to maintain the vertical state of the drilling rig's drill shaft, and ultimately affecting the quality control and smooth implementation of cement mixing pile construction. In view of this, technical improvements are made on the basis of embodiment 1, and the improved technical solution is as follows: Reference Figures 1 to 8 As shown, the present invention proposes a construction method for aerodynamic sand geological soft soil hardening mixing piles, and the construction method comprises the following steps: S1, the pile driver travels to the position, the traction device 2 lowers the drill rod 4, and the driving unit drives the drill rod 4 to perform the pile drilling process.

[0054] S2. Identify the soil layer where the current drill rod 4 is located through the stroke identification unit 8 and the torque detection unit, and transmit the identified soil layer information to the data acquisition unit.

[0055] S3. Perform real-time detection and adjustment of the verticality of the drill pipe 4 through a verticality checking unit.

[0056] S301, constructing a horizontal reference plane by means of a horizontal calibration unit arranged at the bottom of the pile driver.

[0057] S302, judging whether the bottom of the pile driver is in a horizontal state during the drilling process of the drill rod 4, if it is in a horizontal state, the drilling state is maintained, if it is in a non-horizontal state, entering S303.

[0058] S303, determine whether the deflection angle of the bottom surface of the pile driver exceeds the preset value. If it exceeds the preset value, suspend the drilling operation and control the traction device 2 to lift the drill rod 4; if it does not exceed the preset value, the bottom surface of the pile driver is leveled by adjusting the support leg balancing unit 5, and return to S302. At the same time, the soil layer where the drill rod 4 is currently located is marked as a deflected layer, and the soil layer information is uploaded to the data acquisition unit.

[0059] It should be noted that the leg balancing unit 5 in this embodiment includes telescopic legs arranged on the periphery of the frame and driven by hydraulic pressure.

[0060] S4. Determine whether the drilling depth of the drill rod 4 is in place by the stroke identification unit 8. If it is in place, enter S5. If it is not in place, return to S2 and continue the drilling operation.

[0061] S5. According to the soil layer information collected by the data acquisition unit, the drill rod 4 performs the lifting and spraying operation.

[0062] Digital electronic levels are installed at the drill rod 4, bracket 7 and key nodes of the fuselage to form a three-dimensional monitoring network that can communicate and transmit data to the screen in the cockpit.

[0063] Specifically: the electronic level set on the X-axis is used to monitor the left and right tilt (along the drill rod 4 horizontally); the electronic level set on the Y-axis is used to monitor the front and rear tilt (along the drill rod 4 longitudinally); the electronic level set on the Z-axis is used to monitor the fuselage torsion (optional, used in complex terrain).

[0064] It should be noted that the sensor needs to be embedded in the protective cover to avoid direct impact from sand particles, and close to the support foot to improve the adjustment relevance.

[0065] The STM32 microcontroller is used to integrate sensor data and transmit it to the monitoring terminal through the I2C protocol.

[0066] The sampling frequency was set to ≥50 Hz, and the Kalman filter algorithm was used to eliminate sand vibration noise.

[0067] The deviation threshold is set according to the characteristics of aeolian sand (for example, an alarm is triggered when the inclination angle is greater than 0.3° or the cumulative deviation is greater than 5cm).

[0068] The three-dimensional tilt model (such as center dot + offset vector arrow) is displayed in real time on the cockpit display screen to assist the operator in making intuitive judgments.

[0069] When the pile driver is carrying out a construction operation of mixing piles in aeolian sand, if the drill rod 4 is detected to be deviated, an alarm unit is triggered to alarm (the alarm unit includes an audible and visual alarm).

[0070] This embodiment adopts a three-level response mechanism, specifically: When the monitoring terminal detects that the inclination angle of the drill rod 4 is ≤0.5°, the first-level response is triggered. At this time, the drilling state of the drill rod 4 does not change, and the controller continues to monitor the subsequent changes in the inclination angle of the drill rod 4. Although the controller does not immediately adjust the outrigger state, it has begun to closely track the changing trend of the inclination angle. At this time, the hydraulic system inside the telescopic outrigger is in standby mode, and the pressure sensor (the pressure sensor of the hydraulic system itself) continuously monitors the slight pressure fluctuations of the hydraulic oil. These fluctuation data are mutually confirmed with the inclination changes fed back by the electronic level, and data reserves are made for possible subsequent adjustments.

[0071] When the monitoring terminal detects that the inclination angle of the drill rod 4 is at 0.5-1°, the secondary response is triggered, and the controller quickly analyzes the data of each electronic level in the three-dimensional monitoring network to determine the main direction of the inclination (such as the left and right inclination of the X-axis or the front and back inclination of the Y-axis). Subsequently, the controller sends an adjustment instruction to the telescopic leg in the corresponding direction. For example, if the X-axis electronic level shows that the drill rod 4 is tilted to the left, the telescopic leg on the right side of the fuselage starts to move. Under the precise control of the controller, its hydraulic cylinder adjusts the flow and pressure of the hydraulic oil to slowly extend the leg, pushing the right side of the fuselage to lift slightly. At the same time, the left leg is fine-tuned accordingly to maintain stable support to offset the tilting trend.

[0072] During the adjustment process, the controller continuously receives real-time data from the electronic level and uses the PID control algorithm to dynamically adjust the extension of the telescopic legs to ensure a smooth and accurate adjustment process. When the electronic levels distributed on the pile driver return to a stable state, that is, when the inclination angle returns to the allowable range, the controller records the relevant parameters of this adjustment, including the extension of each leg, adjustment time, etc., and marks the current soil layer as a deflected layer. At the same time, the soil layer information is uploaded to the data acquisition unit to provide a reference for subsequent construction.

[0073] When the monitoring terminal detects that the inclination angle of the drill rod 4 is greater than 1°, the third-level response is triggered, the traction device stops running and triggers the emergency brake, and the controller takes full control of the telescopic legs. At this time, although the pile driver needs to be leveled, the drill rod no longer performs drilling work. The first task is to safely and efficiently pull the drill rod out of the pile hole to avoid equipment damage or construction accidents due to increased inclination.

[0074] Under the instruction of the controller, the traction device 2 lifts the drill rod at a preset slow and uniform speed to avoid the hole wall collapse or the drill rod jamming due to rapid withdrawal.

[0075] While the drill rod is being pulled out, the controller starts the three-dimensional collaborative leveling program: the controller comprehensively considers the data of all electronic levels in the three-dimensional monitoring network and coordinates the telescopic legs in four directions. For example, if the tilt angle mainly exists along the X-axis and Y-axis directions at the same time, and the fuselage is also accompanied by a certain degree of twist (if there is data feedback from the Z-axis electronic level), the controller will send different adjustment instructions to the four legs at the same time, and by accurately controlling the extension of each leg, the fuselage can be reset as a whole in three-dimensional space. At the same time, the operator can observe the three-dimensional tilt model and the adjustment status of each leg in real time through the display screen in the cockpit, and can intuitively understand the adjustment process of the pile driver. If necessary, the adjustment operation can also be manually intervened to ensure that the pile driver always maintains a safe and stable construction state in the complex wind-blown sand environment.

[0076] Embodiment 3

[0077] Although the above-mentioned embodiment can adjust the horizontal state of the pile driver through the support balance unit 5 during the drilling process of the drill rod 4 to avoid the problem of the drill rod 4 being offset, in the actual application process, due to the geological characteristics of the windy and sandy areas, when the pile driver is performing the lifting and grouting operation, the slurry is easy to quickly diffuse and lose in the highly permeable sand layer, resulting in a decrease in the slurry concentration in the area, forming a so-called "slurry-poor area". On the contrary, in a dense soil layer, the slurry may accumulate due to the obstruction of penetration, forming a "slurry-rich area". This uneven distribution of slurry further leads to differences in the strength of the pile body, which in turn affects the overall bearing capacity stability of the composite foundation. In view of this, technical improvements are made on the basis of Example 2, and the improved technical solution is as follows: Reference Figures 1 to 8 As shown, the present invention proposes a construction method for aerodynamic sand geological soft soil hardening mixing piles, and the construction method comprises the following steps: S1, the pile driver travels to the position, the traction device 2 lowers the drill rod 4, and the driving unit drives the drill rod 4 to perform the pile drilling process.

[0078] S2. Identify the soil layer where the current drill rod 4 is located through the stroke identification unit 8 and the torque detection unit, and transmit the identified soil layer information to the data acquisition unit.

[0079] S3. Perform real-time detection and adjustment of the verticality of the drill pipe 4 through a verticality checking unit.

[0080] S4. Determine whether the drilling depth of the drill rod 4 is in place by the stroke identification unit 8. If it is in place, enter S5. If it is not in place, return to S2 and continue the drilling operation.

[0081] S5. According to the soil layer information collected by the data acquisition unit, the drill rod 4 performs the lifting and spraying operation.

[0082] S501, after the drill rod 4 is drilled into place, the traction device 2 lifts up the drill rod 4 and starts the spraying unit at the same time.

[0083] S502: When the drill rod 4 is lifted up, the soil layer where the drill rod 4 is located is judged and identified according to the stroke identification unit 8 and the data acquisition unit.

[0084] S503, the shotcrete unit performs corresponding shotcrete operations according to the type of soil layer where the drill rod 4 is currently located.

[0085] If the soil layer where the drill rod 4 is currently located is a soft soil layer, a first-level shotcreting operation is performed; if the soil layer where the drill rod 4 is currently located is a hard soil layer, a second-level shotcreting operation is performed; if the soil layer where the drill rod 4 is currently located is a gravel layer, a third-level shotcreting operation is performed.

[0086] If the soil layer where the drill rod 4 is currently located is a deflected layer, the fourth-level shotcrete operation is performed.

[0087] During the drilling process of the drill rod 4, the stroke identification unit 8 determines whether the drilling depth of the drill rod 4 is in place. If not, the drilling operation continues. If it is in place, the controller controls the traction device 2 to drive the drill rod 4 to move upward, and controls the spraying pump 601 to start. The spraying pump 601 sprays the slurry from the bottom of the drill rod 4 through the grouting pipe 602. During the process of the drill rod 4 being lifted and rotated, the slurry is evenly mixed with the soil layer.

[0088] During the process of lifting the drill rod 4 for shotcrete, the corresponding shotcrete mixing operation is performed according to the soil layer information collected by the data acquisition unit, as shown below: In the process of the drill rod 4 performing the shotcrete operation, based on the soil layer characteristic data acquired by the data acquisition unit, the controller will accurately control the shotcrete device 6 and the drive unit to implement the graded shotcrete mixing operation. The specific operation is as follows: When the drill rod 4 is in the gravel layer for grouting, the controller will activate the three-level grouting mixing operation mode. In this mode, the drive unit will drive the first drilling rod 401 and the second drilling rod 402 to rotate alternately in opposite directions at high speed, and use the strong shear force generated by the two to crush the gravel, ensuring that the slurry and gravel are deeply mixed. In order to improve the mixing efficiency, the rotation speed of the second drilling rod 402 is set to be higher than that of the first drilling rod 401, so that while crushing the gravel, the slurry can be more effectively dispersed into the gaps between the gravel, effectively preventing the formation of lean slurry areas. At the same time, the slurry delivery pump delivers the slurry at a large flow rate and high pressure to ensure that the pores in the gravel layer are fully filled and the formation of lean slurry areas is avoided. In addition, high pressure can also help the slurry overcome the resistance of the gravel and achieve uniform distribution of the slurry in the entire mixing area.

[0089] When the drill rod 4 is in the hard soil layer for grouting operation, the controller will start the secondary grouting mixing operation mode. In this mode, the drive unit controls the first drilling rod 401 and the second drilling rod 402 to rotate in opposite directions (such as the first drilling rod 401 rotates clockwise and the second drilling rod 402 rotates counterclockwise) to enhance the shearing effect on the soil, promote soil crushing and the full mixing of the slurry and the soil. In view of the poor permeability of the hard soil layer to the slurry, in order to ensure that the mixing space is fully filled and the mixing is uniform, the slurry delivery pump adopts a medium flow and medium pressure delivery method to cope with the problem of poor permeability of the slurry in the hard soil layer, and prevent the hard soil and the slurry from being difficult to fully mix and forming a lean slurry area.

[0090] When the drill rod 4 is in the soft soil layer for grouting operation, the controller will start the first-level grouting mixing operation mode. In this mode, the drive unit controls the first drilling rod 401 and the second drilling rod 402 to rotate in the same direction at a low speed. Since the soft soil layer is loose, the same-direction rotation can make the mixing process more uniform, effectively avoiding excessive disturbance of the soil layer and damage to the soil structure caused by reverse rotation. This operation can not only ensure that the slurry is fully mixed with the soil, but also prevent excessive stirring of the soil and loss of slurry due to excessive rotation speed. At the same time, the slurry delivery pump uses a medium flow and low pressure delivery method to ensure that the slurry is continuously and evenly filled into the stirred soft soil during the upward movement of the drill rod 4, avoiding the formation of a lean slurry area due to insufficient slurry supply in some areas due to too small a flow rate, or the formation of a rich slurry area due to accumulation of slurry in local areas due to excessive flow rate.

[0091] It should be noted that when the drill rod 4 performs grouting in the deflected layer, the controller will start the four-level grouting mixing operation mode. In this mode, the drive unit controls the first drilling rod 401 and the second drilling rod 402 to rotate alternately in the opposite direction at a low speed to offset the deflection inertia force, so that the drill rod 4 maintains a relatively stable motion state in the deflected layer; and prolongs the mixing time of the slurry and the soil to enhance the curing effect. At the same time, the slurry delivery pump uses a large flow and high pressure delivery method to compensate for the uneven slurry diffusion problem caused by the deflection of the drill rod 4. The large flow rate can ensure that the slurry can be quickly and fully filled into the voids in the deflected layer, and the high pressure can enhance the penetration ability of the slurry, so that the slurry can better combine with the soil. At the same time, pulse grouting (intermittent injection) is used to promote slurry penetration by using pressure fluctuations. Pulse grouting can form a pressure gradient for the slurry in the soil, making it easier for the slurry to penetrate into the tiny pores of the soil.

[0092] It should be noted that the flow and pressure are regulated by the frequency converter and the proportional valve. The controller adjusts the output frequency of the frequency converter and the opening of the proportional valve in real time according to the degree of deflection of the drill rod 4 and the actual situation of the soil layer, thereby accurately controlling the flow and pressure of the slurry.

[0093] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for constructing soft soil hardening mixing piles in aeolian sand geology, characterized in that: The construction method comprises the following steps: S1. The pile driver moves to the right position, the traction device lowers the drill rod, and the drive unit drives the drill rod to perform the pile drilling process; S2, identifying the soil layer where the current drill rod is located through the stroke identification unit and the torque detection unit, and transmitting the identified soil layer information to the data acquisition unit; S3, real-time detection and adjustment of the verticality of the drill pipe through the verticality verification unit; S4, judging whether the drilling depth of the drill rod is in place through the stroke identification unit, if it is in place, entering S5, if not, returning to S2 and continuing the drilling operation; S5. According to the soil layer information collected by the data acquisition unit, the drill rod performs corresponding lifting and shotcreting operations; The drill rod comprises a first drill rod and a second drill rod, the first drill rod and the second drill rod are sleeved together, and the first drill rod and the second drill rod are respectively connected to a driving unit so that the rotation of the first drill rod and the second drill rod can be controlled separately.

2. The method for constructing soft soil hardened mixing piles in aeolian sand geology according to claim 1, characterized in that: The S2 soil layer identification includes the following steps: S201, collecting drilling depth data of the drill rod through a stroke identification unit, and collecting torque data of the drill rod through a torque detection unit; S202, during the drilling process of the drill rod, determine whether the torque change of the drill rod exceeds a first threshold; if it does not exceed the first threshold, mark the current soil layer as a soft soil layer and upload the soil layer information to the data acquisition unit; if it exceeds the first threshold, enter S203; S203, determine whether the torque change of the drill rod exceeds the second threshold; if the value exceeds the first threshold but is less than the second threshold, mark the current soil layer as a hard soil layer and upload the soil layer information to the data acquisition unit; if it exceeds the second threshold, mark the current soil layer as a gravel layer and upload the soil layer information to the data acquisition unit.

3. The method for constructing soft soil hardened mixing piles in aeolian sand geology according to claim 2, characterized in that: The verticality check of the S3 drill pipe includes the following steps: S301, constructing a horizontal reference plane by means of a horizontal calibration unit arranged at the bottom of the pile driver; S302, judging whether the bottom of the pile driver is in a horizontal state during the drilling process of the drill rod, if it is in a horizontal state, the drilling state is maintained, if it is in a non-horizontal state, the process proceeds to S303; S303, determine whether the deflection angle of the bottom surface of the pile driver exceeds the preset value. If it exceeds the preset value, suspend the drilling operation and control the traction device to lift the drill rod; if it does not exceed the preset value, adjust the bottom surface of the pile driver by adjusting the support leg balance unit, and return to S302. At the same time, mark the soil layer where the drill rod is currently located as a deflected layer, and upload the soil layer information to the data acquisition unit.

4. The method for constructing soft soil hardened mixing piles in aeolian sand geology according to claim 3, characterized in that: The S5 lifting shotcrete operation comprises the following steps: S501, after the drill rod is drilled into place, the traction device lifts the drill rod and starts the spraying unit at the same time; S502, during the process of lifting the drill rod, the soil layer where the drill rod is located is judged and identified according to the stroke identification unit and the data acquisition unit; S503, the shotcrete unit performs corresponding shotcrete operations according to the type of soil layer where the drill rod is currently located.

5. The method for constructing soft soil hardened mixing piles in aeolian sand geology according to claim 4, characterized in that: If the soil layer where the drill rod is currently located is a soft soil layer, a first-level shotcreting operation is performed; if the soil layer where the drill rod is currently located is a hard soil layer, a second-level shotcreting operation is performed; if the soil layer where the drill rod is currently located is a gravel layer, a third-level shotcreting operation is performed.

6. The method for constructing soft soil hardened mixing piles in aeolian sand geology according to claim 4, characterized in that: If the soil layer where the drill rod is currently located is a deflected layer, a fourth-level shotcrete operation is performed.

7. The method for constructing soft soil hardened mixing piles in aeolian sand geology according to claim 2, characterized in that: The stroke identification unit includes an induction disk arranged on the traction device, on which an array of induction blocks is arranged, and on the outer side of the induction disk is a collecting piece for identifying the induction blocks, and the collecting piece obtains the lifting speed and lifting stroke of the drill rod by collecting the number of induction blocks passing through per unit time.

8. The method for constructing soft soil hardened mixing piles in aeolian sand geology according to claim 3, characterized in that: The level checking unit comprises a digital electronic level distributed in an array on the pile driver.

9. The method for constructing soft soil hardened mixing piles in aeolian sand geology according to claim 2, characterized in that: The torque detection unit includes a torque sensor arranged at an output end of the driving unit.

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