MJS combined reinforcing method for groove wall and pit bottom of operation station

Abstract

The invention relates to the technical field of underground foundation pit enclosure construction, in particular to an operation station groove wall and pit bottom MJS combined reinforcing method. Jumping pile construction is adopted, namely, the two sides of the station are constructed at the same time, the disturbance influence on the station is reduced, and the operation stability of the groove wall of the operation station is improved; by optimizing and improving the reinforcing construction method, the stable operation of the groove wall of the station is guaranteed, meanwhile, the construction efficiency is improved, and the positive effect on improving the overall construction benefit is achieved; in the machining construction process, the calibration auxiliary device is used for positioning the calibration steel bars, the repeated debugging frequency of the calibration steel bars is reduced, even the repeated debugging work of the calibration steel bars is avoided, the calibration steel bars are accurately positioned, the paying-off construction efficiency is improved, and then the positive influence on improvement of the overall construction benefits is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of underground foundation pit enclosure construction, and in particular to an MJS combined reinforcement method for a trench wall and a pit bottom of an operating station. Background Art

[0002] The existing application document with the publication number CN116537216A discloses a construction method for reinforcing the underground continuous wall trench of a subway station with complex geological conditions near a lake; the method comprises the following steps:

[0003] S10: Marking the construction pile position according to the control points of the jet grouting pile construction determined by the total station to obtain the position of the pile position mark point;

[0004] S20: Dig slurry discharge troughs according to the pile position marking points and set up the mortar mixing system;

[0005] S30: moving the geological drilling rig to the designated pile position mark point, and drilling the pile position mark point to obtain a bored pile position;

[0006] S40: moving the jet grouting machine to the corresponding bored pile position, aligning the drill bit with the center of the bored pile position, performing jet grouting inside the bored pile position, and obtaining a jet grouting pile column after the slurry solidifies;

[0007] S50: cleaning the return slurry on the top of the jet grouting pile column and introducing the return slurry into the sedimentation tank through the slurry discharge trough;

[0008] S60: Rinse the grouting pipe and other equipment with clean water;

[0009] In the scheme, the construction pile positions are marked according to the control points of the rotary jet pile construction determined by the total station. The specific steps for obtaining the marked points are: clearing obstacles within 2 meters below the ground of the construction site, leveling the site, using the total station to determine the control points of the rotary jet pile construction, burying stone marks, and after the test line is qualified again, the pile positions are laid out on the spot with a steel ruler and a measuring line, and nailed tightly with bamboo sticks to ensure one pile and one stick, so that the displacement deviation of the pile hole center is less than 50mm, and the position of the pile mark point is obtained; wherein, the specific steps of digging a slurry trough according to the position of the pile mark point and setting up a mortar mixing system are: calibrating the size, depth and length of the slurry trough according to the position of the pile mark point, using a spirit level and a plumb line to determine the position of the edge of the slurry trough, excavating with an excavator, and setting up a mortar mixing system at the same time.

[0010] In the above scheme and the prior art, during the reinforcement construction of the trench wall, reinforcement walls are set on both sides of the trench wall and the bottom of the pit. In the actual construction, a total station and a level are used for the layout operation, a steel tape is used for positioning, and the pile positions are marked with steel bars. The pile positions need to be re-measured during the construction positioning. When using the steel bar calibration work, on the one hand, it is inconvenient to locate the steel bars, and it is easy to cause the steel bars to tilt when inserted into the ground, which requires multiple debugging in the later stage, which brings inconvenience to its construction.

[0011] To this end, the present invention proposes a MJS combined reinforcement method for the pit wall and pit bottom of an operating station to solve the above problems. Summary of the Invention

[0012] The object of the present invention is to provide a method for joint reinforcement of the pit wall and pit bottom MJS of an operating station to solve the problems raised in the above background technology.

[0013] To achieve the above objectives, the present invention provides the following technical solutions: an operating station trough wall, comprising a pit wall and a pit bottom, wherein a first reinforcement wall is laid on the pit wall, and a second reinforcement wall is laid on the bottom of the pit bottom.

[0014] A pit bottom MJS combined reinforcement method, including an operating station trough wall,

[0015] Laying out the lines: Use a total station and a level, a steel tape measure for positioning, and use calibration steel bars to mark the pile positions. Use calibration auxiliary devices to assist in positioning the calibration steel bars.

[0016] Inspection of pipelines and obstacles: There are many pipelines in the construction area, and the teams need to be briefed on the pipelines; before construction, a sample trench is excavated to inspect the pipelines.

[0017] Drilling: Before the MJS pile driver is deployed, a drill head, model MDL-150D, is used. The drill bit is equipped with a tri-lobe and diamond drill bits, allowing the MJS pile driver to penetrate obstacles such as miscellaneous fill, plain fill layers, and bulges in the ground-anchored wall. The error between the hole center and the pile position is less than 50mm, and the verticality error is less than 0.5%.

[0018] Horizontal hole construction and installation of hole sealing device: Drilling is divided into two stages. During the first stage of drilling, a diamond drill is used to drill the hole to the outer surface of the outermost steel bar, leaving a concrete protective layer to prevent sudden surges, then the drill bit and core are pulled out, and the hole sealing device is installed; installation method: remove the concrete on the surface of the ground-connected wall to expose the outer steel bar, insert the connecting block of the hole sealing device into the drilled hole, weld it to the ground-connected wall steel bar after leveling, seal it with fast-setting cement around it, and then install the hole sealing device to create conditions for the MJS drilling rig to self-lead the hole; during the second stage of drilling, drill from the hole sealing device and penetrate the underground continuous wall. After drilling to the designed length, pull back the drill rod in time. When the drill bit is pulled back to the gate valve of the hole sealing device, close the gate valve in time to prevent mud and water from flowing back into the working well and causing deformation of the operating line station structure.

[0019] Put the pile driver in place: ① Connect the power supply, data cable, various pipelines, drill bit and underground pressure monitoring display, confirm that the drill bit is reset to zero when there is no load, and ensure that the pipeline connection is sealed so that there is no air in the pipe.

[0020] ② Check the operation of the equipment to ensure that the main engine, high-pressure pump, air compressor, mud mixing system, MJS management device, etc. are in normal working condition. Put the main engine in place and start zeroing after the frame is placed stably.

[0021] ③ Lowering the drill rod, that is, lowering the drill rod to the designed depth in the pilot hole. If the drill rod is difficult to lower, turn on the cutting water and carry out normal cutting drilling.

[0022] ④ When docking the drill rod and drill bit, carefully check the sealing ring to see if it is missing or damaged, and whether the underground pressure is normal.

[0023] Shotcrete: After the pile driver drill bit reaches the predetermined depth, zero calibration is started, so that the "0" scale on the power head, the nozzle, and the white line on the drill rod are in the same straight line. Then, the various process parameters are set. After setting, the improvement is started. For fixed-position spraying, first start the backflow of water and backflow of air. After confirming that the slurry discharge is normal, open the mud discharge valve, and start the high-pressure cement pump and the main air compressor. First, use water to spray upward 50cm at a pressure of 10Mpa. Then switch the water to cement slurry. After the drill rod is lowered into place, start the upward spraying improvement. When starting the high-pressure cement pump, the pressure should not be too high. It should be increased gradually until the specified pressure is reached. After reaching the specified pressure and confirming that the underground pressure is normal, it can be increased. When the water is switched to cement slurry, the pressure will automatically rise. The pressure can only be adjusted when there is a sudden change in pressure. Closely monitor the underground pressure during shotcrete. If the pressure is abnormal, the size of the mud discharge valve must be adjusted in time to control the underground pressure within a safe range.

[0024] Rod disassembly: After lifting a drill rod, the drill rod is disassembled. The cement slurry needs to be switched to water before disassembly. When the pressure of the cement slurry pump tends to decrease, it means that the water flow has reached the nozzle position. At this time, turn off the cement slurry pump, main air, backdraft air and backdraft water flow.

[0025] When disassembling the drill rod, carefully check the seal ring and data line to see if they are damaged and whether the ground pressure display is normal. If there is any problem, it should be eliminated in time before continuing the grouting. After disassembling the drill rod, it needs to be flushed and maintained in time.

[0026] After lifting a drill rod, disassemble the drill rod. While disassembling the drill rod, carefully inspect the seals and data cables. Repeat the above steps until the installation is complete. After the installation is complete, flush and maintain the equipment.

[0027] Final hole: After each horizontal reinforcement operation is completed, the installed grouting holes are used to carry out secondary compaction grouting in the reinforcement dead corner area. After the vertical reinforcement grouting is completed, the top concave hole is filled with cement grout.

[0028] Pile Testing: Grouting pile quality testing should be conducted 28 days after construction. The number of quality inspection points should be 1% to 2% of the number of construction holes, and should not be less than 3 points. Any unqualified piles should be re-sprayed. The unconfined compressive strength of the MJS-reinforced soil after 28 days should be 2.0 MPa ≤ qu28 ≤ 5 MPa, the flexural strength should be greater than 0.2 MPa, and the shear strength should be greater than 0.2 MPa.

[0029] Preferably, an auxiliary sphere is fixedly provided at one end of the calibration steel bar, and a reflective strip is provided on the auxiliary sphere.

[0030] Material toggling mechanism, its both sides respectively have a cylinder pressure, and the cylinder pressure bar connects swing arm, and the swing arm end face has hook portion, and a bar passes position between the end of two swing arms and the hook portion.

[0031] Preferably, the pressure plate corresponds to the setting position of the calibration steel bars and the number of setting groups is the same.

[0032] Preferably, the bearing slider corresponds to the setting position of the sliding groove and is provided in the same number of groups; the limiting slide corresponds to the setting position of the limiting slide and is provided in the same number of groups, and the limiting slide is slidably connected in the limiting slide.

[0033] Preferably, the auxiliary clamping pads are configured as rubber pads, and the auxiliary clamping pads and the extrusion screws are configured at corresponding positions and in the same number of groups.

[0034] Preferably, one extrusion screw is provided in the bearing slider, and the extrusion screw corresponds to the setting position of the calibration steel bar.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention designs a combined reinforcement method for the trough wall of an operating station and a corresponding pit bottom MJS; the method adopts skipping pile construction, that is, construction on both sides of the station at the same time, to reduce the impact of disturbance on the station and improve the operational stability of the trough wall of the operating station; by optimizing and improving the reinforcement construction method, while ensuring the stable operation of the station trough wall, its construction efficiency is improved, and has a positive effect on improving the overall construction benefit; during the processing and construction process, the calibration steel bars are positioned by the provided calibration auxiliary device, which saves the number of repeated debugging times and even avoids the repeated debugging work, so that the calibration steel bars are accurately positioned, the layout construction efficiency is improved, and thus has a positive effect on improving the overall construction benefit. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the connection of the groove wall structure of the present invention;

[0038] Figure 2 A top view of the connection between the calibration auxiliary device and the calibration steel bar structure of the present invention;

[0039] Figure 3 For the present invention Figure 2 A magnified schematic diagram of the structural connection at center A;

[0040] Figure 4 This is a bottom view of the connection between the calibration auxiliary device of the present invention and the calibration steel bar structure;

[0041] Figure 5 For the present invention Figure 4 A magnified schematic diagram of the structural connection at point B in the middle;

[0042] Figure 6 This is a schematic diagram of the connection between the load-bearing slider and the extrusion screw structure in the calibration auxiliary device of the present invention;

[0043] Figure 7 For the present invention Figure 6 A magnified schematic diagram of the structural connection at point C in the middle;

[0044] Figure 8 This is a process flow chart of the vertical reinforcement construction of MJS piles according to the present invention;

[0045] Figure 9 This is a flowchart of the horizontal reinforcement construction process of the MJS method piles of the present invention.

[0046] In the figure: pit wall 1, pit bottom 2, first reinforcement wall 3, second reinforcement wall 4, calibration steel bar 5, auxiliary sphere 501, reflective strip 502, bearing platform 601, hydraulic cylinder 602, pressure plate 603, support leg 604, support foot 605, sliding groove 606, loading port 607, limiting slide groove 608, bearing slider 609, limiting slide bar 610, connecting spring 611, extrusion screw 612, rotating handle 613, auxiliary clamping pad 614. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present invention are described clearly and completely below. The embodiments of the present invention and all other embodiments obtained by persons of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0048] Example 1: Please refer to Figure 1-Figure 7 A pit wall of an operating station includes a pit wall 1 and a pit bottom 2. A first reinforcement wall 3 is laid on the pit wall 1, and a second reinforcement wall 4 is laid on the bottom of the pit bottom 2.

[0049] A pit bottom MJS combined reinforcement method, including an operating station trough wall,

[0050] Laying out the lines: Use a total station and a level, a steel tape for positioning, and use calibration steel bars 5 to mark the pile positions. Use calibration auxiliary devices to assist in positioning the calibration steel bars 5.

[0051] Inspection of pipelines and obstacles: There are many pipelines in the construction area, and the teams need to be briefed on the pipelines; before construction, a sample trench is excavated to inspect the pipelines.

[0052] Drilling: Before the MJS pile driver is deployed, a drill head, model MDL-150D, is used. The drill bit is equipped with a tri-lobe and diamond drill bits, allowing the MJS pile driver to penetrate obstacles such as miscellaneous fill, plain fill layers, and bulges in the ground-anchored wall. The error between the hole center and the pile position is less than 50mm, and the verticality error is less than 0.5%.

[0053] Horizontal hole construction and installation of hole sealing device: Drilling is divided into two stages. During the first stage of drilling, a diamond drill is used to drill the hole to the outer surface of the outermost steel bar, leaving a concrete protective layer to prevent sudden surges, then the drill bit and core are pulled out, and the hole sealing device is installed; installation method: remove the concrete on the surface of the ground-connected wall to expose the outer steel bar, insert the connecting block of the hole sealing device into the drilled hole, weld it to the ground-connected wall steel bar after leveling, seal it with fast-setting cement around it, and then install the hole sealing device to create conditions for the MJS drilling rig to self-lead the hole; during the second stage of drilling, drill from the hole sealing device and penetrate the underground continuous wall. After drilling to the designed length, pull back the drill rod in time. When the drill bit is pulled back to the gate valve of the hole sealing device, close the gate valve in time to prevent mud and water from flowing back into the working well and causing deformation of the operating line station structure.

[0054] Put the pile driver in place: ① Connect the power supply, data cable, various pipelines, drill bit and underground pressure monitoring display, confirm that the drill bit is reset to zero when there is no load, and ensure that the pipeline connection is sealed so that there is no air in the pipe.

[0055] ② Check the operation of the equipment to ensure that the main engine, high-pressure pump, air compressor, mud mixing system, MJS management device, etc. are in normal working condition. Put the main engine in place and start zeroing after the frame is placed stably.

[0056] ③ Lowering the drill rod, that is, lowering the drill rod to the designed depth in the pilot hole. If the drill rod is difficult to lower, turn on the cutting water and carry out normal cutting drilling.

[0057] ④ When docking the drill rod and drill bit, carefully check the sealing ring to see if it is missing or damaged, and whether the underground pressure is normal.

[0058] Shotcrete: After the pile driver drill bit reaches the predetermined depth, zero calibration is started, so that the "0" scale on the power head, the nozzle, and the white line on the drill rod are in the same straight line. Then, the various process parameters are set. After setting, the improvement is started. For fixed-position spraying, first start the backflow of water and backflow of air. After confirming that the slurry discharge is normal, open the mud discharge valve, and start the high-pressure cement pump and the main air compressor. First, use water to spray upward 50cm at a pressure of 10Mpa. Then switch the water to cement slurry. After the drill rod is lowered into place, start the upward spraying improvement. When starting the high-pressure cement pump, the pressure should not be too high. It should be increased gradually until the specified pressure is reached. After reaching the specified pressure and confirming that the underground pressure is normal, it can be increased. When the water is switched to cement slurry, the pressure will automatically rise. The pressure can only be adjusted when there is a sudden change in pressure. Closely monitor the underground pressure during shotcrete. If the pressure is abnormal, the size of the mud discharge valve must be adjusted in time to control the underground pressure within a safe range.

[0059] Rod disassembly: After lifting a drill rod, the drill rod is disassembled. The cement slurry needs to be switched to water before disassembly. When the pressure of the cement slurry pump tends to decrease, it means that the water flow has reached the nozzle position. At this time, turn off the cement slurry pump, main air, backdraft air and backdraft water flow.

[0060] When disassembling the drill rod, carefully check the seal ring and data line to see if they are damaged and whether the ground pressure display is normal. If there is any problem, it should be eliminated in time before continuing the grouting. After disassembling the drill rod, it needs to be flushed and maintained in time.

[0061] After lifting a drill rod, disassemble the drill rod. While disassembling the drill rod, carefully inspect the seals and data cables. Repeat the above steps until the installation is complete. After the installation is complete, flush and maintain the equipment.

[0062] Final hole: After each horizontal reinforcement operation is completed, the installed grouting holes are used to carry out secondary compaction grouting in the reinforcement dead corner area. After the vertical reinforcement grouting is completed, the top concave hole is filled with cement grout.

[0063] Pile Testing: Grouting pile quality testing should be conducted 28 days after construction. The number of quality inspection points should be 1% to 2% of the number of construction holes, and should not be less than 3 points. Any unqualified piles should be re-sprayed. The unconfined compressive strength of the MJS-reinforced soil after 28 days should be 2.0 MPa ≤ qu28 ≤ 5 MPa, the flexural strength should be greater than 0.2 MPa, and the shear strength should be greater than 0.2 MPa.

[0064] Horizontal pile diameter 2400mm Level bite 600mm vertical pile diameter 1500mm vertical bite 500mm Cutting water pressure 0~20MPa Pile plane deviation ≤50mm Water-cement ratio 0.7～1.0 Pile hole depth deviation ≤150mm Verticality ≤1 / 200mm Pile diameter deviation ≤50mm Shotcrete pressure ≥40MPa Increase speed 40min / m (full circle), 20min / m (semicircle) Cement slurry flow rate 85~100L / min pressure in the earth 1.3~1.6 coefficient Main air pressure 0.7MPa Cement content 40％ Air flow <![CDATA[1.0~2.0m 3 / min]]> Drilling accuracy ≤1％ Pile top 0~+100mm Pile end ±100mm 28d unconfined compressive strength 2.0MPa≤qu28≤5MPa 28d flexural strength >0.2MPa 28d shear strength >0.2MPa Slurry specific gravity ±0.05

[0065] Table 1- Technical parameters of MJS piles

[0066] Among these are quality control measures;

[0067] (1) Before construction, process pile tests shall be carried out according to the geological conditions to calibrate various construction technical parameters.

[0068] (2) Before construction, the team should be briefed on underground obstacles and pipelines. If any exist, protective measures such as identification, detection, and excavation of sample trenches should be implemented. The MJS all-round high-pressure jet grouting equipment, pilot hole drilling rig, high-pressure mud pump, slurry mixing backstage, and water pump should be tested. At the same time, it should be ensured that the drill rods (especially multiple drill rods), drill bits, and guide devices are unobstructed. All raw materials used for reinforcement (including cement, etc.) must provide quality certificates and witness test reports, and the mixing water should meet the corresponding regulations.

[0069] (3) When drilling holes near the ground-connected wall of the operating line, first use a core tube to drill the hole. When encountering a bulge in the ground-connected wall, switch to a core tube combined with a diamond drill bit to complete the drilling. During the drilling process of the ground-connected wall bulge, strengthen the inspection and random inspection of its verticality, and increase the monitoring frequency of existing stations. If the monitoring data is abnormal, stop drilling immediately. After analysis and disposal, the monitoring data returns to normal before continuing the construction.

[0070] (4) Strictly control the verticality of the pilot hole. Use a pilot drill bit to pilot the hole. Use an inclinometer or total station to spot check the verticality of the drill rod. The number of spot checks should not be less than 30% of the total number of piles. When the drill rod deviates too much, lift the drill rod to a position with good verticality and start to sweep the hole. If the hole cannot be swept, backfill and re-pilot the hole. Increase the frequency of spot checks by 2 times until the verticality stabilizes and the frequency is restored to 30%.

[0071] (5) During the construction of the MJS method, the ground pressure is strictly controlled, and mud drainage is handled promptly to avoid excessive disturbance of the surrounding soil and deformation of the existing station.

[0072] (6) Strictly control the direction of the MJS method. After the semi-circular spraying is started, the operator must correct the direction each time the rod is removed and the spraying is started. The technical staff should strengthen the inspection of the verticality of the drill rod, the drilling speed, the drilling depth, the drilling speed and the rotation speed to see if they are consistent with the requirements of the trial pile report.

[0073] (7) To ensure that the piles do not break when the drill rod is dismantled or the operation is interrupted for a long time due to some reasons, the overlap length of the upper and lower piles should not be less than 100 cm when normal injection is resumed.

[0074] (8) Establish a monitoring response system with the internal monitoring system of a subway station on the operating line, and promptly reflect the monitoring data of a subway station on the operating line to the construction site. If any abnormality is found, adjust the construction immediately.

[0075] (9) The site is equipped with sufficient slips, oil connectors, solenoid valves, encoders, scales, data cables and other types of wearing parts.

[0076] (10) Treatment of blind spots in horizontal reinforcement spraying of MJS: During horizontal MJS spraying, the slurry is sprayed at a 2.5° forward angle. Therefore, when the nozzle is 8 cm away from the underground continuous wall, the slurry can be sprayed onto the underground continuous wall to form a reinforcement body. A new grouting injection port can be added to the front end of the drill bit, and the spraying time can be extended to eliminate the reinforcement blind spot and achieve the effect of overlapping with the remote underground structure.

[0077] (11) Anti-gushing control for ultra-deep boreholes: The anti-gushing device is installed in two parts: a valve and a nozzle. It can effectively achieve the safe connection between the artificial horizontal drilling rig drilling hole at the near end of the reinforcement and the horizontal MJS self-drilling hole. At the same time, the three rows of O-rings installed in the nozzle can form a good seal between the drill pipe and the sealing ring.

[0078] (12) Measures taken to solve the problem of mud discharge in deep foundation pits: The mud in the horizontal MJS method in ultra-deep foundation pits is transported in a closed manner using hard steel pipes. A relay pump can be installed, and an appropriate amount of polymer modifiers such as bentonite or polyacrylamide can be added to increase the workability of the mud, thereby solving the problem of mud discharge in the horizontal MJS method in ultra-deep foundation pits.

[0079] (13) Measures taken to solve the problem of difficulty in fixing the power head base and inaccurate centering of the modified equipment: a hydraulic lifting platform was installed on site. The hydraulic lifting platform is supported by a scissor-type structure and uses the extension and contraction of the hydraulic cylinder to automatically complete a series of processes and tasks such as platform lifting and distributing the load evenly. Setting a firm limit on the hydraulic lifting platform can effectively solve the problem of power head base displacement. The lifting height is evenly controlled by oil pressure, and after fine-tuning, the multi-hole pipe is accurately aligned with the hole to be reinforced.

[0080] (14) Measures to prevent the failure of long-distance porous pipe joints: ① During the process of grouting and pulling out the pipes, two or more sections of porous pipes can be disassembled as a whole to reduce the number of joints; ② Special pipe racks are equipped on site to place porous pipes to prevent mud, sand and gravel and other debris from entering the cleaned porous pipes again due to messy stacking; ③ Multiple MJS equipment are constructed at the same time to ensure that each equipment uses a fixed set of porous pipes to avoid joint failure caused by different sealing fit due to cross-use; ④ A drill pipe test bench is equipped on site to check the integrity of the drill pipe and hydraulic one-way valve before drilling to avoid blind inspection after all drill pipes are installed due to "slurry leakage" found in the porous pipes during grouting.

[0081] (15) Measures to be taken when slurry return system failures occur frequently in disturbed soil: ① Operate the drill to open and close the slurry discharge gate to control the size of the slurry discharge opening; ② Install a filter plug inside the drill slurry discharge opening. ③ If cement lumps are adsorbed on the slurry discharge opening during construction, this can be resolved by pulling out and rotating the porous pipe.

[0082]

[0083] Table 2-MJS exception handling measures

[0084] Example 2: Based on Example 1, please refer to Figure 2-Figure 7 An auxiliary sphere 501 is fixedly provided at one end of the calibration steel bar 5 , and a reflective strip 502 is provided on the auxiliary sphere 501 .

[0085] The calibration auxiliary device here includes a load-bearing platform 601, a hydraulic cylinder 602, a pressure plate 603, a support leg 604, a support foot 605, a sliding groove 606, a loading port 607, a limiting sliding groove 608, a load-bearing slider 609, a limiting slider 610, a connecting spring 611, an extrusion screw 612, a rotating handle 613, and an auxiliary clamping pad 614; a hydraulic cylinder 602 is fixedly provided on the load-bearing platform 601, one end of the hydraulic cylinder 602 extends to the bottom side of the load-bearing platform 601, and the bottom of the hydraulic cylinder 602 is fixed to the bottom side of the load-bearing platform 601. A pressure plate 603 is fixedly provided at the end, and support legs 604 are fixedly provided at the four side positions of the load-bearing platform 601. A support foot 605 is fixedly provided at the bottom end of the support leg 604, and a sliding groove 606 is provided through the support leg 604. A loading port 607 is provided at the top of the sliding groove 606. A limited sliding groove 608 is symmetrically provided on both sides of the sliding groove 606. A load-bearing slider 609 is movably provided in the sliding groove 606. A limited sliding bar 610 is symmetrically fixed on both sides of the load-bearing slider 609. The bottom end of the slider 609 is symmetrically fixed with a connecting spring 611, the other end of the connecting spring 611 is fixedly set at the bottom end position of the sliding groove 606, the extrusion screw 612 is threadedly connected and set in the bearing slider 609, one end of the extrusion screw 612 is fixedly provided with a rotating handle 613, and the other end of the extrusion screw 612 is fixedly provided with an auxiliary clamping pad 614; the pressure plate 603 here corresponds to the setting position of the calibration steel bar 5 and the setting number is the same; the bearing slider 609 here is connected to the sliding The grooves 606 are set in corresponding positions and the number of groups is the same; the limiting slide 610 is set in corresponding positions and the number of groups is the same as the limiting slide 608, and the limiting slide 610 is slidably connected in the limiting slide 608; the auxiliary clamping pad 614 here is set as a rubber pad, and the auxiliary clamping pad 614 is set in corresponding positions and the number of groups as the extrusion screw 612; the extrusion screw 612 here is set in one in the bearing slider 609, and the extrusion screw 612 corresponds to the setting position of the calibration steel bar 5.

[0086] This embodiment is to optimize the positioning of the calibration steel bar 5 during the layout construction. First, one end of the calibration steel bar 5 is inserted into the ground. Then, the bearing platform 601 in the calibration auxiliary device is placed directly above the calibration steel bar 5. Then, the extrusion screw 612 on the bearing slider 609 is tightened so that one end of the extrusion screw 612 squeezes the side wall of the calibration steel bar 5. A total of four groups of extrusion screws 612 are provided to extrude and position the calibration steel bar 5 and keep it in a vertical state to avoid tilting problems. Here, an auxiliary clamping pad is provided at the extrusion end of the extrusion screw 612. 614, as the compaction proceeds, the auxiliary clamping pad 614 can wrap and clamp the side wall of the calibration steel bar 5, thereby improving its limiting stability; finally, the hydraulic cylinder 602 drives the pressure plate 603, so that the pressure plate 603 squeezes the auxiliary sphere 501, thereby making the calibration steel bar 5 vertically and stably inserted into the ground, thereby improving the accuracy and stability of its calibration work; here, after the positioning work of the calibration steel bar 5 is completed, the reflective strip 502 set on the top auxiliary sphere 501 can serve as a simple warning to avoid touching it during other construction.

[0087] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A trough wall of an operating station, characterized by: The invention comprises a pit wall (1) and a pit bottom (2), wherein a first reinforcement wall (3) is laid on the pit wall (1), and a second reinforcement wall (4) is laid on the bottom of the pit bottom (2).

2. A pit bottom MJS combined reinforcement method, comprising the operating station trough wall according to claim 1, characterized in that: Laying out: Using a total station and a level, positioning with a steel tape, marking the pile positions with calibration steel bars (5), and assisting in positioning the calibration steel bars (5) with calibration auxiliary devices. Inspection of pipelines and obstacles: There are many pipelines in the construction area, and the teams need to be briefed on the pipelines; before construction, a sample trench is excavated to inspect the pipelines. Drilling: Before the MJS pile driver is deployed, a drill head, model MDL-150D, is used. The drill bit is equipped with a tri-lobe and diamond drill bits, allowing the MJS pile driver to penetrate obstacles such as miscellaneous fill, plain fill layers, and bulges in the ground-anchored wall. The error between the hole center and the pile position is less than 50mm, and the verticality error is less than 0.5%. Horizontal hole construction and installation of hole sealing device: Drilling is divided into two stages. During the first stage of drilling, a diamond drill is used to drill the hole to the outer surface of the outermost steel bar, leaving a concrete protective layer to prevent sudden surges, then the drill bit and core are pulled out, and the hole sealing device is installed; installation method: remove the concrete on the surface of the ground-connected wall to expose the outer steel bar, insert the connecting block of the hole sealing device into the drilled hole, weld it to the ground-connected wall steel bar after leveling, seal it with fast-setting cement around it, and then install the hole sealing device to create conditions for the MJS drilling rig to self-lead the hole; during the second stage of drilling, drill from the hole sealing device and penetrate the underground continuous wall. After drilling to the designed length, pull back the drill rod in time. When the drill bit is pulled back to the gate valve of the hole sealing device, close the gate valve in time to prevent mud and water from flowing back into the working well and causing deformation of the operating line station structure. Put the pile driver in place: ① Connect the power supply, data cable, various pipelines, drill bit and underground pressure monitoring display, confirm that the drill bit is reset to zero when there is no load, and ensure that the pipeline connection is sealed so that there is no air in the pipe. ② Check the operation of the equipment to ensure that the main engine, high-pressure pump, air compressor, mud mixing system, MJS management device, etc. are in normal working condition. Put the main engine in place and start zeroing after the frame is placed stably. ③ Lowering the drill rod, that is, lowering the drill rod to the designed depth in the pilot hole. If the drill rod is difficult to lower, turn on the cutting water and carry out normal cutting drilling. ④ When docking the drill rod and drill bit, carefully check the sealing ring to see if it is missing or damaged, and whether the underground pressure is normal. Shotcrete: After the pile driver drill bit reaches the desired depth, zero calibration is initiated, aligning the power head's "0" scale, the nozzle, and the white line on the drill pipe. Then, various process parameters are set. Once these are complete, the process begins. For fixed-position spraying, reverse suction of water and air is initiated. Once the slurry discharge is confirmed to be normal, the slurry discharge valve is opened, and the high-pressure cement pump and main air compressor are turned on. First, water is sprayed upwards 50cm at a pressure of 10Mpa. Then, the water is switched to cement slurry. After the drill pipe is lowered back into position, the upward spraying process begins. When starting a high-pressure cement pump, the pressure should not be too high. It should be increased gradually until the specified pressure is reached. Only after reaching the specified pressure and confirming that the ground pressure is normal can it be increased. When water is switched to cement slurry, the pressure will automatically rise. The pressure should only be adjusted if there is a sudden change in pressure. During shotcrete, the ground pressure should be closely monitored. If the pressure is abnormal, the discharge valve must be adjusted in time to keep the ground pressure within a safe range. Rod disassembly: After lifting a drill rod, the drill rod is disassembled. The cement slurry needs to be switched to water before disassembly. When the pressure of the cement slurry pump tends to decrease, it means that the water flow has reached the nozzle position. At this time, turn off the cement slurry pump, main air, backdraft air and backdraft water flow. When disassembling the drill rod, carefully check the seal ring and data line to see if they are damaged and whether the ground pressure display is normal. If there is any problem, it should be eliminated in time before continuing the grouting. After disassembling the drill rod, it needs to be flushed and maintained in time. After lifting a drill rod, disassemble the drill rod. While disassembling the drill rod, carefully inspect the seals and data cables. Repeat the above steps until the installation is complete. After the installation is complete, flush and maintain the equipment. Final hole: After each horizontal reinforcement operation is completed, the installed grouting holes are used to carry out secondary compaction grouting in the reinforcement dead corner area. After the vertical reinforcement grouting is completed, the top concave hole is filled with cement grout. Pile Testing: Grouting pile quality testing should be conducted 28 days after construction. The number of quality inspection points should be 1% to 2% of the number of construction holes, and should not be less than 3 points. Any unqualified piles should be re-sprayed. The unconfined compressive strength of the MJS-reinforced soil after 28 days should be 2.0 MPa ≤ qu28 ≤ 5 MPa, the flexural strength should be greater than 0.2 MPa, and the shear strength should be greater than 0.2 MPa.

3. The pit bottom MJS combined reinforcement method according to claim 1, characterized in that: An auxiliary sphere (501) is fixedly provided at one end of the calibration steel bar (5), and a reflective strip (502) is provided on the auxiliary sphere (501).

4. The pit bottom MJS combined reinforcement method according to claim 1, characterized in that: The calibration auxiliary device comprises a bearing platform (601), a hydraulic cylinder (602), a pressure plate (603), a support leg (604), a support foot (605), a sliding groove (606), a loading port (607), a limiting sliding groove (608), a bearing slider (609), a limiting slide bar (610), a connecting spring (611), an extrusion screw (612), a rotating handle (613), and an auxiliary clamping pad (614); a hydraulic cylinder (602) is fixedly provided on the bearing platform (601), one end of the hydraulic cylinder (602) extends to the bottom side of the bearing platform (601), and a pressure plate (603) is fixedly provided at the bottom end of the hydraulic cylinder (602), and support legs (604) are fixedly provided at the four side positions of the bearing platform (601), and support feet (605) are fixedly provided at the bottom end of the support legs (604), and the support legs (605) are fixedly provided at the bottom end of the support legs (604). A sliding groove (606) is provided through the leg (604), a loading port (607) is provided at the top of the sliding groove (606), and limiting sliding grooves (608) are symmetrically provided on both sides of the sliding groove (606). The supporting slider (609) is movably provided in the sliding groove (606), and limiting sliding strips (610) are symmetrically fixedly provided on both sides of the supporting slider (609). A connecting spring (611) is symmetrically fixedly provided at the bottom end of the supporting slider (609), and the other end of the connecting spring (611) is fixedly provided at the bottom end position of the sliding groove (606). The extrusion screw (612) is threadedly connected and provided in the supporting slider (609), and a rotating handle (613) is fixedly provided at one end of the extrusion screw (612), and an auxiliary clamping pad (614) is fixedly provided at the other end of the extrusion screw (612).

5. The pit bottom MJS combined reinforcement method according to claim 4, characterized in that: The pressure plate (603) and the calibration steel bars (5) are arranged at corresponding positions and have the same number of groups.

6. The pit bottom MJS combined reinforcement method according to claim 4, characterized in that: The bearing slider (609) and the sliding groove (606) are arranged at corresponding positions and are arranged in the same number of groups; the limiting slide (610) and the limiting slide (608) are arranged at corresponding positions and are arranged in the same number of groups, and the limiting slide (610) is slidably connected in the limiting slide (608).

7. The pit bottom MJS combined reinforcement method according to claim 4, characterized in that: The auxiliary clamping pads (614) are configured as rubber pads, and the auxiliary clamping pads (614) and the extrusion screws (612) are configured at corresponding positions and have the same number of groups.

8. The pit bottom MJS combined reinforcement method according to claim 4, characterized in that: One extrusion screw rod (612) is provided in the bearing slider (609), and the extrusion screw rod (612) corresponds to the setting position of the calibration steel bar (5).

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