Method for repairing seepage pit between deep foundation pit supporting piles in high groundwater level

Abstract

The present application relates to a kind of high groundwater level deep foundation pit supporting pile between seepage water pit repair method, surface muscle net is set along the open surface of supporting pile between pit, and top stable body is formed by pouring in upper portion;First air bag and formwork top bracing bolt are used to position supporting side mold;First pressure grouting pipe and reinforcing mesh are preset in pit backfill body;Make pipe bottom anchor nail insert into first pressure grouting pipe, and support bottom plate is set;Pile side connecting groove and pile side guide rail are sequentially set on the outside of supporting pile, and first support plate and second support plate can be applied by pressing bolt and support plate pressure groove to exert pressure;First support plate is preset with grout hole, and water body that seeps out between supporting pile pit can be collected by water collecting groove.The present application can meet the reinforcement backfilling of supporting pile between pit at the same time, realizes the control exclusion of seepage water in supporting pile between pit, and protects environment.

Description

Technical Field

[0001] This invention relates to a method for repairing seepage craters between support piles in deep foundation pits with high groundwater levels. This method can reduce seepage pollution in foundation pits, improve the integrity of craters between support piles, and reduce the difficulty of repairing craters between support piles. It is applicable to deep foundation pit support projects with high groundwater levels. Background Technology

[0002] During the excavation of the foundation pit, groundwater outside the pit seeps into the pit through the soil between the piles, and washes away a large amount of soil between the piles. This not only seriously interferes with the subsequent construction in the pit, but also has a great adverse effect on the deformation and safety of the support system.

[0003] Currently, in the restoration and treatment of scour between support piles, the common method is to hang a steel mesh between the support piles and then spray concrete. One existing method for scour restoration between support piles uses expansion bolts to connect the support piles and transverse reinforcement bars, with T-shaped anchor bars anchored into the soil at the top transverse reinforcement bar. A steel mesh is also installed, connected to multiple transverse reinforcement bars to form a whole. A sprayed concrete protective layer is then applied, and a flow-guiding device including filter media and a filter screen is installed below the groundwater level of the concrete protective layer. While this method can achieve backfilling of scour pits between support piles and improve the safety of the support structure, there are still areas for improvement in terms of environmental protection during construction, efficient on-site retaining and protection, and enhancing the overall integrity of the repaired structure.

[0004] Therefore, in order to improve the quality and efficiency of the repair construction of seepage crater between support piles, there is an urgent need to invent a repair method for seepage crater between support piles in deep foundation pits with high groundwater levels that can improve the stability of the soil in the crater before filling, increase construction efficiency, enhance the filling strength of the crater between support piles, and reduce the pollution of foundation pits caused by seepage. Summary of the Invention

[0005] The purpose of this invention is to provide a method for repairing seepage craters between support piles in deep foundation pits with high groundwater levels, which can not only improve the efficiency and airtightness of template support, but also enhance the strength and integrity of the crater filling, and control the pollution caused by seepage in the foundation pit.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] A method for repairing seepage erosion pits between support piles in deep foundation pits with high groundwater levels includes the following steps:

[0008] 1) Construction preparation:

[0009] The groundwater level of the external soil outside the support pile is determined by surveying and drilling dewatering holes in the external soil to be reinforced, and the groundwater level of the external soil is lowered through the dewatering holes; the first hoop plate, the second hoop plate, the third hoop plate, the pile side guide rail, the first support plate and the second support plate are prefabricated.

[0010] 2) Installation of the first grouting pipe and reinforcing mesh:

[0011] Pre-install bottom anchors at the bottom of the first grouting pipe, and then evenly distribute the first grouting pipe along the length of the support base plate; first move the support base plate and the first grouting pipe, which are connected as a whole, to the bottom of the scour pit between the support piles, and insert the bottom anchors into the foundation soil; then install reinforcing mesh between the longitudinally adjacent first grouting pipes; then insert oblique anchor bars into the outer soil in an upward direction, and firmly connect the oblique anchor bars to the upper anchor plate; lay a layer of surface reinforcement mesh along the free surface of the scour pit between the support piles.

[0012] 3) Pile side guide rail layout:

[0013] The pile side hoop plate is firmly connected to the support pile by the pile side anchor bar, and the pile side connecting groove is set on the first hoop plate and the second hoop plate; the limiting sliding tenon of the pile side guide rail is inserted into the guide rail slot of the bottom support plate from top to bottom, and a lower support beam is set between the support plate limiting grooves of the two mirror-opposite pile side guide rails, and an upper support beam is set between the two mirror-opposite third hoop plates.

[0014] 4) Arrangement of the first and second support plates:

[0015] First and second support plates are inserted sequentially along mirror-image pile side guides from top to bottom, with the first support plate on the side closer to the external soil and the second support plate on the side farther from the external soil. Support plate grooves are set at the top of the first and second support plates, and the upper surface of the support plate grooves is connected to the lower pressure bolts on the lower support beam. Grouting holes are pre-set on the first support plate, and a water collection trough is set at the bottom of the gap between the first and second support plates, and the water collection trough is connected to external pumping equipment through a drainage pipe.

[0016] 5) Top stabilizing element installation:

[0017] First, the groundwater level of the external soil is lowered through dewatering holes, and the seepage water at the bottom is collected through a drainage channel. Then, a lower support plate is installed on the side of the lower support beam facing the external soil, and an upper support plate is installed on the side of the upper support beam facing the external soil. Three to four height adjustment bolts are installed on the upper support plate, and the top of the height adjustment bolts is welded to the horizontal connecting body. The dredging formwork includes an inclined bottom formwork and a vertical side formwork, and the inclined bottom formwork is connected to the formwork positioning frame, and the formwork positioning frame is connected to the horizontal connecting body through the horizontal adjustment bolts. The gap between the formwork top pressure bolts and the surface reinforcement mesh is grouted between the lower support plate and the inclined bottom formwork to form a top stable body. After the top stable body has gained strength, the dredging formwork is removed.

[0018] 6) Deployment of the first and second airbags:

[0019] A rectangular first airbag and two trapezoidal second airbags are set on the side of the first support plate facing the external soil. The sidewall of the first airbag is bonded to the sidewall of the support side formwork. The airbag filling material is injected into the first and second airbags simultaneously through an external grouting device.

[0020] 7) Construction of backfill material for dredging pits:

[0021] Two formwork top support bolts are installed between the lower support plates, and the included angle between the two formwork top support bolts is 60~90°; first, the support side formwork is made perpendicular to the horizontal plane through the formwork top support bolts; concrete is poured into the gap between the support side formwork and the surface reinforcement mesh using external concrete pouring equipment to form the backfill body of the crater.

[0022] As a preferred technical solution of the present invention, in the method for repairing seepage scour pits between support piles of deep foundation pits with high groundwater levels:

[0023] The supporting base plate in step 2) is made of rolled steel plate, and pre-drilled holes for the bottom anchors of the pipe are made on the supporting base plate; the first grouting pipe is made of rolled steel pipe, and the sidewall of the first grouting pipe with 3 to 10 post-grouting holes evenly spaced on the pipe wall is welded to the reinforcing mesh; the reinforcing mesh is steel mesh; the upper anchor plate is made of rolled steel plate, welded to the reinforcing mesh, and pre-drilled holes for the oblique anchor bars to pass through are made on the upper anchor plate.

[0024] The pile side hoop plates mentioned in step 3) include a first hoop plate, a second hoop plate, and a third hoop plate, which are sequentially installed from bottom to top along the height direction of the support pile on the outside of the support pile; the pile side connecting groove is made of rolled steel plate, and a guide rail groove with a "T" shaped cross section is preset on the pile side connecting groove, and the sliding tenon fastening bolt passes through the pile side connecting groove and is firmly connected to the limiting sliding tenon; the bottom support plate is made of rolled steel plate, and a guide rail slot and a support plate slot are set on the upper surface of the bottom support plate; the guide rail slot is made of rolled steel plate, with a trapezoidal cross section, and is welded to the bottom support plate; the pile side guide rail is made of rolled steel plate, one side is welded to the limiting sliding tenon, and two parallel support plate limiting slots are set on both sides vertically.

[0025] In step 4), both the first and second support plates are made of rolled steel plates, and both ends are inserted into the support plate limiting grooves on the pile side guide rail; two support plate suspension cables are provided on both the first and second support plates; the net width of the water collection channel and the second support plate are equal.

[0026] In step 5), the template positioning frame is made of steel plate rolled into a "π" shape and welded to the horizontal adjustment bolt; the horizontal adjustment bolt, the height adjustment bolt and the template top pressure bolt all include a screw and a nut, and the tightening directions of the screws on both sides of the nut are opposite; a top pressure ball hinge is provided at the connection between the template top pressure bolt and the inclined bottom formwork; the inclined bottom formwork and the vertical side formwork are made of steel plate or aluminum alloy plate of the same material, and the vertical side formwork and the inclined bottom formwork are pre-connected firmly according to the depth of the scour pit between the support piles.

[0027] In step 6), the first airbags are all made of rubber sheets sewn into a sealed cavity, and pipes connected to the external grouting device are respectively set on the first airbags; the airbag filling material is water or mud; a bag weight is set on the upper part of the first airbag, and the bag weight is connected to the lower support plate by the lower pressure control body.

[0028] This invention has the following characteristics and beneficial effects:

[0029] (1) The present invention sets a surface reinforcement mesh along the free surface of the scour pit between the support piles, and first pours a top stable body on the upper part of the scour pit to avoid the problem of further expansion of the scour pit area between the support piles before the construction of the lower scour pit backfill body.

[0030] (2) The present invention uses the first airbag and the template top support bolt to position the support side formwork, which can not only improve the template support efficiency, but also enhance the sealing effect of the gap between the support piles.

[0031] (3) The present invention pre-sets a first grouting pipe and a reinforcing mesh in the backfill body of the scour pit, which can play the role of reinforcing the bottom of the backfill body of the scour pit; the bottom anchor is inserted into the first grouting pipe and a supporting bottom plate is set, which can play the role of improving the bottom anti-overturning stability and reducing the concentrated stress.

[0032] (4) The present invention provides pile side connecting groove and pile side guide rail on the outside of the support pile in sequence, which can realize accurate guidance of the first support plate and the second support plate. At the same time, the present invention can apply downward pressure to the first support plate and the second support plate through the pressing bolt and the support plate pressing groove, thereby enhancing the stability of the first support plate and the second support plate.

[0033] (5) The present invention has a grout passage hole pre-set on the first support plate, and the water seeping out of the scour pit between the support piles can be collected through the water collection channel, thus avoiding the pollution of the foundation pit by the seepage water before the construction of the scour pit backfill. Attached Figure Description

[0034] Figure 1 This is a flowchart of the repair process for seepage and scouring pits between support piles in deep foundation pits with high groundwater levels.

[0035] Figure 2 This is a schematic diagram of the vertical section of the structure for repairing seepage and scouring pits between support piles in deep foundation pits with high groundwater levels.

[0036] Figure 3 This is a schematic diagram of a cross-section of the repair of seepage craters between support piles in deep foundation pits with high groundwater levels.

[0037] Figure 4 This is a schematic diagram of the positioning structure of the second support plate.

[0038] The symbols in the attached diagram represent the following: 1-Support pile; 2-External soil; 3-Drainage hole; 4-First hoop plate; 5-Second hoop plate; 6-Third hoop plate; 7-Pile side guide rail; 8-First support plate; 9-Second support plate; 10-First grouting pipe; 11-Pipe bottom anchor; 12-Support base plate; 13-Foundation soil; 14-Reinforcing mesh; 15-Inclined anchoring bar; 16-Upper anchor plate; 17-Surface reinforcement mesh; 18-Pile side anchor bar; 19-Pile side hoop plate; 20-Pile side connecting groove; 21-Limiting sliding tenon; 22-Bottom support plate; 23-Guide rail groove; 24-Support plate limiting groove; 25-Lower support beam; 26-Upper support beam; 27-Support plate pressing groove; 28-Lower pressing bolt; 29-Grouting hole; 30 31-Water collection channel; 32-Drainage pipe; 33-Lower support plate; 34-Upper support plate; 35-Height adjustment bolt; 36-Horizontal connector; 37-Pit hoisting formwork; 38-Sloping bottom formwork; 39-Vertical side formwork; 40-Formwork positioning frame; 41-Horizontal adjustment bolt; 42-Formwork top pressure bolt; 43-Top stabilizing body; 44-First airbag; 45-Second airbag; 46-Supporting side formwork; 47-Formwork top support bolt; 48-Pit backfill body; 49-Guide rail groove; 50-Support pile inter-pile pit; 51-Sliding tenon fastening bolt; 52-Supporting plate suspension cable; 53-Top pressure ball hinge; 54-Bag counterweight body; 55-Lower pressure control body; 56-Airbag filling body; 57-Rear grouting hole. Specific Implementation

[0039] The technical requirements for concrete pouring, steel plate rolling and welding, and the stitching of the first and second airbags are not elaborated in this embodiment. The focus is on describing the implementation method of the method involved in this invention.

[0040] Figure 1 This is a flowchart illustrating the repair process for seepage and scour pits between support piles in deep foundation pits with high groundwater levels, as shown in the figure. The repair method for seepage and scour pits between support piles in deep foundation pits with high groundwater levels includes the following steps:

[0041] 1) Construction preparation: Survey and determine the groundwater level of the external soil 2 outside the support pile 1, drill dewatering holes 3 in the external soil 2 to be reinforced, and lower the groundwater level of the external soil 2 through the dewatering holes 3; prefabricate the first hoop plate 4, the second hoop plate 5, the third hoop plate 6, the pile side guide rail 7, the first support plate 8, and the second support plate 9.

[0042] 2) Installation of the first grouting pipe and reinforcement mesh: First, install the bottom anchor 11 at the bottom of the first grouting pipe 10, and then evenly install the first grouting pipe 10 along the length of the supporting base plate 12; first, move the supporting base plate 12 and the first grouting pipe 10, which are connected as a whole, to the bottom of the scour pit 50 between the support piles, and insert the bottom anchor 11 into the foundation soil 13; then, install the reinforcement mesh 14 between the longitudinally adjacent first grouting pipes 10; then, insert the oblique anchor bar 15 into the outer soil 2 in an upward direction, and firmly connect the oblique anchor bar 15 to the upper anchor plate 16; lay a layer of surface reinforcement mesh 17 along the free surface of the scour pit 50 between the support piles.

[0043] 3) Pile side guide rail layout: The pile side hoop plate 19 is firmly connected to the support pile 1 by the pile side anchor bar 18, and pile side connecting grooves 20 are set on the first hoop plate 4 and the second hoop plate 5; the limiting sliding tenon 21 of the pile side guide rail 7 is inserted into the guide rail slot 23 of the bottom support plate 22 from top to bottom, and the support plate limiting grooves 24 of the two mirror-opposite pile side guide rails 7 are in the same axis; a lower support beam 25 is set between the mirror-opposite pile side connecting grooves 20, and an upper support beam 26 is set between the two mirror-opposite third hoop plates 6;

[0044] 4) Arrangement of the first and second support plates: The first support plate 8 and the second support plate 9 are inserted sequentially from top to bottom along the mirror-image pile side guide rail 7, with the first support plate 8 on the side closer to the external soil 2 and the second support plate 9 on the side away from the external soil 2; a support plate groove 27 is set at the top of the first support plate 8 and the second support plate 9, and the upper surface of the support plate groove 27 is connected to the lower pressure bolt 28 on the lower support beam 25; a grouting hole 29 is preset on the first support plate 8, and a water collection trough 30 is set at the bottom of the gap between the first support plate 8 and the second support plate 9, and the water collection trough 30 is connected to the external pumping equipment through the drainage pipe 31;

[0045] 5) Top Stabilization Structure Setup: First, lower the groundwater level of the external soil 2 through the dewatering holes 3, collect the seepage water at the bottom through the water collection trough 30, then set a lower support plate 32 on the side of the lower support beam 25 facing the external soil 2, and set an upper support plate 33 on the side of the upper support beam 26 facing the external soil 2; set 3-4 height adjustment bolts 34 on the upper support plate 33, and weld the top of the height adjustment bolts 34 to the transverse connecting body 35; the crater formwork 36 includes an inclined bottom formwork 37 and a vertical side formwork 38, and connect the inclined bottom formwork 37 to the formwork positioning frame 39, and connect the formwork positioning frame 39 to the transverse connecting body 35 through transverse adjustment bolts 40; set a formwork top pressure bolt 41 between the lower support plate 32 and the inclined bottom formwork 37; grout the gap between the crater formwork 36 and the surface reinforcement mesh 17 through external grouting equipment to form the top stabilization structure 42; after the top stabilization structure 42 has gained strength, remove the crater formwork 36;

[0046] 6) Arrangement of the first and second airbags: A rectangular first airbag 43 and two trapezoidal second airbags 44 are set on the side of the first support plate 8 facing the external soil 2. The side wall of the first airbag 43 is bonded to the side wall of the supporting side mold 45. The airbag filling body 56 is injected into the first airbag 43 and the second airbag 44 simultaneously through the external grouting device.

[0047] 7) Construction of backfill material for scour pit: Two formwork top support bolts 46 are set between the lower support plate 32 and the support side formwork 45, and the included angle between the two formwork top support bolts 46 is 60~90°; first, the support side formwork 45 is made perpendicular to the horizontal plane through the formwork top support bolts 46; concrete is poured into the gap between the support side formwork 45 and the surface reinforcement mesh 17 using external concrete pouring equipment to form backfill material 47 for scour pit.

[0048] Figure 2 This is a schematic diagram of the vertical section of the structure for repairing seepage craters between support piles in deep foundation pits with high groundwater levels. Figure 3 This is a schematic cross-sectional view of the repair of seepage erosion pits between support piles in deep foundation pits with high groundwater levels. Figure 4 yes Figure 2 Schematic diagram of the positioning structure of the second support plate. (Refer to...) Figures 2-4 As shown, the implementation methods for each component of the repair method for seepage erosion pits between support piles in deep foundation pits with high groundwater levels are as follows.

[0049] The diameter of the support pile 1 is 600mm, and the net distance between two adjacent support piles 1 is 1m. The external soil 2 and the foundation soil are both medium-dense sandy soils. The groundwater level is 2m higher than the upper surface of the foundation soil 13. The dimensions of the scour pit 50 formed between the support piles are 2.2m high, 0.5m deep and 1m wide.

[0050] The diameter of the drainage hole 3 is 100mm, and a permeable hose with a diameter of 90mm is inserted into the hole.

[0051] The first hoop plate 4, the second hoop plate 5, and the third hoop plate 6 each consist of two identical semi-circular hoops, made of steel plates with a thickness of 2mm, with an inner diameter the same as the outer diameter of the support pile, and fastened with bolts of 10mm diameter.

[0052] The pile side guide rail 7, the first support plate 8, and the second support plate 9 are all made of steel plates with a thickness of 10mm.

[0053] The first grouting pipe 10 is made of steel pipe with a diameter of 50mm and has three grouting holes 57 with a diameter of 40mm evenly arranged on its pipe wall.

[0054] The bottom anchor 11 is made of threaded steel bar with a diameter of 20mm, so that the bottom anchor 11 is inserted into the foundation soil 13 to a depth of 200mm.

[0055] The support base plate 12 is made of steel plate with a thickness of 10mm and has pre-drilled holes for the pipe bottom anchor nails 11 to pass through.

[0056] A first grouting pipe 10 is installed every 30cm along the length of the support base plate 12, and the support base plate 12 is welded to the first grouting pipe 10 perpendicularly.

[0057] The reinforcing mesh 14 is made of steel mesh with a mesh size of 100mm×100mm, and the reinforcing mesh 14 is welded and fixed to the first grouting pipe 10 that is longitudinally adjacent.

[0058] The inclined anchor bar 15 is made of threaded steel bar with a diameter of 32mm;

[0059] The upper anchor plate 16 is made of 10mm thick steel plate and a hole with a diameter of 40mm is reserved on the upper anchor plate 16 for the oblique anchor bar 15 to pass through.

[0060] The surface reinforcement mesh 17 is a steel mesh with a mesh size of 100mm×100mm.

[0061] The pile side anchor bar 18 is made of 32mm diameter threaded steel bar rolled into a hole and planted into the side wall of the support pile 1, so that one end of the pile side anchor bar 18 is firmly connected to the support pile 1, and the other end passes through the reserved hole of the pile side hoop plate 19 and is firmly welded to the pile side hoop plate 19.

[0062] The pile side connecting groove 20 is welded on the first hoop plate 4 and the second hoop plate 5. The pile side connecting groove 20 is made of steel plate with a thickness of 10mm. At the same time, holes for the sliding tenon fastening bolt 51 to pass through are pre-set on the side wall of the pile side connecting groove 20.

[0063] A limiting sliding tenon 21 is welded to one side of the pile side guide rail 7. The limiting sliding tenon 21 is made of steel plate with a thickness of 10mm and has a cross-section in the shape of a "T". The bottom support plate 22 is made of steel plate with a thickness of 10mm and has a cross-section in the shape of an inverted trapezoid. It is welded and fixed to the bottom support plate 22, so that the pile side guide rail 7 is inserted into the guide rail slot 23 of the bottom support plate 22.

[0064] The two sides of the pile side guide rail 7 are provided with two parallel support plate limiting grooves 24. The depth of the support plate limiting grooves 24 on the pile side guide rail 7 is 80mm and the width is 20mm. The first support plate 8 and the second support plate 9 are inserted along the support plate limiting grooves 24 on the pile side guide rail 7.

[0065] A lower support beam 25 is set between the mirror-opposite pile side connecting grooves 20, and a hole is reserved on the lower support beam 25 for the lower pressing bolt 28 to pass through. An upper support beam 26 is set between the two mirror-opposite third hoop plates 6. Both the lower support beam 25 and the upper support beam 26 are made of H-beams with a specification of 200×200×8×12.

[0066] The support plate groove 27 is made of 10mm thick steel plate, with a groove reserved on its lower surface for the insertion of the first support plate 8 and the second support plate 9, and its upper surface is connected to the pressing bolt 28 on the lower support beam 25; the pressing bolt 28 is a hexagonal bolt of type M20.

[0067] Ten slurry passage holes 29 with a diameter of 60 mm are arranged within a range of 30-50 cm from the bottom of the first support plate 8.

[0068] The water collection trough 30 is made of steel plate with a thickness of 2mm, and has a cross-section in the shape of "U". Its width is equal to the net width of the first support plate 8 and the second support plate 9, and its height is 30cm.

[0069] The drainage pipe 31 is made of DN32 PVC pipe, with one end connected to the water collection tank 30 and the other end connected to the external pumping equipment.

[0070] Both the lower support plate 32 and the upper support plate 33 are made of steel plates with a thickness of 10mm.

[0071] The height adjustment bolt 34 is composed of a screw and a nut with a diameter of 20mm, and the tightening directions of the screws on both sides of the nut are opposite; three height adjustment bolts 34 are provided on the upper support plate 33, and the top of the height adjustment bolt 34 is welded vertically to the transverse connecting body 35.

[0072] The transverse connecting body 35 is made of steel plate with a thickness of 10mm.

[0073] The punching mold 36 includes an inclined bottom mold 37 and a vertical side mold 38, both of which are made of steel plates with a thickness of 3mm. The inclined bottom mold 37 and the vertical side mold 38 are pre-welded firmly at a 120° angle, and then the inclined bottom mold 37 is welded firmly to the template positioning frame 39.

[0074] The template positioning frame 39 is made of 10mm thick steel plate, with a cross section in the shape of "π", and is welded to the transverse adjusting bolt 40.

[0075] Both the transverse adjusting bolt 40 and the template top pressing bolt 41 consist of a 30mm diameter screw and a nut, with the tightening directions of the screws on both sides of the nut being opposite.

[0076] Cement mortar of grade M20 is injected into the gap between the crater formwork 36 and the surface reinforcement mesh 17 using external grouting equipment to form a top stable body 42.

[0077] The first airbag 43 and the second airbag 44 are both made of rubber sheets with a thickness of 2mm and sewn into a sealed cavity. Pipes connected to the external grouting device are respectively provided on the first airbag 43 and the second airbag 44. The airbag filling material is mud, and the airbag pressure is set to 0.6MPa. The airbag filling material 56 is tap water.

[0078] The supporting side mold 45 is made of steel plate with a thickness of 10mm;

[0079] The template top support bolt 46 is composed of a 20mm diameter screw and a nut, with the tightening directions of the screws on both sides of the nut being opposite; the included angle between the two template top support bolts 46 is 60°, and the template top support bolt 46 is firmly connected to the lower support plate 32 by a ball joint, and is connected to the support side mold 45 by a ball joint.

[0080] C30 concrete is poured into the gap between the supporting side formwork 45 and the surface reinforcement mesh 17 using an external concrete pouring device to form the backfill body 47 for the crater.

[0081] A guide rail groove 48 with a cross-section of "T" is preset in the pile side connecting groove 20, so that the limiting sliding tenon 21 on the pile side guide rail 7 is inserted from top to bottom along the guide rail groove 48 on the pile side connecting groove 20; a support plate slot 49 with a depth of 50mm is preset in the bottom support plate 22.

[0082] The sliding tenon fastening bolt 51 uses a bolt with a diameter of 20mm, so that the sliding tenon fastening bolt 51 passes through the hole reserved on the side wall of the column side connecting groove 20 and is firmly connected to the limiting sliding tenon 21.

[0083] The support plate lifting cable 52 is made of steel wire rope with a diameter of 16mm. Two support plate lifting cables 52 with a diameter of 10mm are set on the first support plate 8 and the second support plate 9. The first support plate 8 and the second support plate 9 are suspended from top to bottom along the support plate limiting groove 24 using the support plate lifting cable 52, and the first support plate 8 and the second support plate 9 are inserted into the support plate slot 49 of the bottom support plate 22.

[0084] The template top pressure bolt 41 is connected to the inclined bottom mold 37 through the top pressure ball joint 53, which is a ball joint with a diameter of 30mm.

[0085] The upper part of the first airbag 43 is provided with a bag ballast body 54, which is composed of cement counterweight blocks with a mass of 15kg.

[0086] The pressure control body 55 connects the bag weight body 54 to the lower support plate 32. The pressure control body 55 is composed of a screw and a nut with a diameter of 20mm, and the tightening directions of the screws on both sides of the nut are opposite.

[0087] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for repairing seepage erosion pits between support piles in deep foundation pits with high groundwater levels, characterized in that, Includes the following steps: 1) Construction preparation: The groundwater level of the external soil (2) outside the support pile (1) is determined by surveying and drilling. Dewatering holes (3) are drilled in the external soil (2) to be reinforced, and the groundwater level of the external soil (2) is lowered through the dewatering holes (3). The first hoop plate (4), the second hoop plate (5), the third hoop plate (6), the pile side guide rail (7), the first support plate (8), and the second support plate (9) are prefabricated. 2) Installation of the first grouting pipe and reinforcing mesh: Beforehand, a pipe bottom anchor (11) is set at the bottom end of the first grouting pipe (10), and then the first grouting pipe (10) is evenly laid along the length of the support base plate (12); the support base plate (12) and the first grouting pipe (10) connected as a whole are moved to the bottom of the scour pit (50) between the support piles, and the pipe bottom anchor (11) is inserted into the foundation soil (13). Then, a reinforcing mesh (14) is set between the longitudinally adjacent first grouting pipes (10), and then the oblique anchoring bars (15) are inserted into the outer soil (2) in an oblique upward direction, and the oblique anchoring bars (15) are firmly connected to the upper anchor plate (16); a layer of surface reinforcement mesh (17) is laid along the free surface of the scour pit (50) between the support piles. 3) Pile side guide rail layout: The pile side hoop plate (19) includes a first hoop plate (4), a second hoop plate (5) and a third hoop plate (6), which are set sequentially from bottom to top along the height direction of the support pile (1) on the outside of the support pile (1); the pile side hoop plate (19) is firmly connected to the support pile (1) by the pile side anchor bar (18), and pile side connecting grooves (20) are set on the first hoop plate (4) and the second hoop plate (5); the limiting sliding tenon (21) of the pile side guide rail (7) is inserted into the guide rail slot (23) of the bottom support plate (22) from top to bottom, and the support plate limiting grooves (24) of the two mirror-opposite pile side guide rails (7) are in the same axis; a lower support beam (25) is set between the mirror-opposite pile side connecting grooves (20), and an upper support beam (26) is set between the two mirror-opposite third hoop plates (6). 4) Arrangement of the first and second support plates: First support plate (8) and second support plate (9) are inserted sequentially along the mirror-image pile side guide rail (7) from top to bottom, with the first support plate (8) on the side closer to the external soil (2) and the second support plate (9) on the side away from the external soil (2); support plate groove (27) is set at the top of the first support plate (8) and the second support plate (9), and the upper surface of the support plate groove (27) is connected to the lower pressure bolt (28) on the lower support beam (25); grouting hole (29) is preset on the first support plate (8), and a water collection trough (30) is set at the bottom of the gap between the first support plate (8) and the second support plate (9), and the water collection trough (30) is connected to the external pumping equipment through the drainage pipe (31); 5) Top stabilizing element installation: First, the groundwater level of the external soil (2) is lowered through the dewatering hole (3), and the seepage water at the bottom is collected through the water collection trough (30). Then, a lower support plate (32) is set on the side of the lower support beam (25) facing the external soil (2), and an upper support plate (33) is set on the side of the upper support beam (26) facing the external soil (2). Three to four height adjustment bolts (34) are set on the upper support plate (33), and the top of the height adjustment bolts (34) is welded to the transverse connecting body (35). The flushing pit formwork (36) includes an inclined bottom formwork ( 37) and vertical side formwork (38), and connect the inclined bottom formwork (37) to the formwork positioning frame (39), and connect the formwork positioning frame (39) to the horizontal connecting body (35) through the horizontal adjusting bolt (40); set the formwork top pressure bolt (41) between the lower support plate (32) and the inclined bottom formwork (37); grout the gap between the crater hanging formwork (36) and the surface reinforcement mesh (17) through the external grouting equipment to form the top stable body (42); after the top stable body (42) has formed strength, remove the crater hanging formwork (36); 6) Deployment of the first and second airbags: A rectangular first airbag (43) and two trapezoidal second airbags (44) are set on the side of the first support plate (8) facing the external soil (2). The side wall of the first airbag (43) is bonded to the side wall of the support side mold (45). The airbag filling body (56) is injected into the first airbag (43) and the second airbag (44) simultaneously through the external grouting device. 7) Construction of backfill material for dredging pits: Two formwork top support bolts (46) are set between the lower support plate (32) and the support side formwork (45), and the included angle between the two formwork top support bolts (46) is 60~90°; first, the support side formwork (45) is made perpendicular to the horizontal plane through the formwork top support bolts (46); concrete is poured into the gap between the support side formwork (45) and the surface reinforcement mesh (17) using external concrete pouring equipment to form the backfill body (47) of the crater.

2. The method for repairing seepage erosion pits between support piles in deep foundation pits with high groundwater levels according to claim 1, characterized in that: The supporting base plate (12) in step 2) is made of rolled steel plate, and a channel for the bottom anchor nail (11) to pass through is pre-set on the supporting base plate (12); the first grouting pipe (10) is made of rolled steel pipe, and 3 to 10 post grouting holes (57) are evenly spaced on the pipe wall of the first grouting pipe (10), and the side wall of the first grouting pipe (10) is welded to the reinforcing mesh (14); the reinforcing mesh (14) is made of steel mesh; the upper anchor plate (16) is made of rolled steel plate, welded to the reinforcing mesh (14), and a hole for the oblique anchoring bar (15) to pass through is pre-set on the upper anchor plate (16).

3. The method for repairing seepage erosion pits between support piles in deep foundation pits with high groundwater levels according to claim 1, characterized in that: In step 3), the pile side connecting groove (20) is made of rolled steel plate. A guide rail groove (48) with a cross section of "T" is preset on the pile side connecting groove (20). A sliding tenon fastening bolt (51) is set on the pile side connecting groove (20), and the sliding tenon fastening bolt (51) passes through the pile side connecting groove (20) and is firmly connected to the limiting sliding tenon (21). The bottom support plate (22) is made of rolled steel plate. A guide rail slot (23) and a support plate slot (49) are set on the upper surface of the bottom support plate (22). The guide rail slot (23) is made of rolled steel plate, with a trapezoidal cross section, and is welded to the bottom support plate (22). The pile side guide rail (7) is made of rolled steel plate, with one side welded to the limiting sliding tenon (21), and two parallel support plate limiting grooves (24) are set on both sides in the vertical direction.

4. The method for repairing seepage erosion pits between support piles in deep foundation pits with high groundwater levels according to claim 1, characterized in that: In step 4), the first support plate (8) and the second support plate (9) are both made of rolled steel plates and inserted into the support plate limiting groove (24) on the pile side guide rail (7) at both ends; two support plate suspension cables (52) are provided on the first support plate (8) and the second support plate (9); the water collection trough (30) is made of rubber plate or steel plate, with a cross section in the shape of "U" and a width equal to the net width of the first support plate (8) and the second support plate (9).

5. The method for repairing seepage erosion pits between support piles in deep foundation pits with high groundwater levels according to claim 1, characterized in that: In step 5), the template positioning frame (39) is made of steel plate rolled into a "π" shape and welded to the horizontal adjustment bolt (40); the horizontal adjustment bolt (40), the height adjustment bolt (34) and the template top pressure bolt (41) all include a screw and a nut, and the tightening directions of the screws on both sides of the nut are opposite; a top pressure ball joint (53) is provided at the connection between the template top pressure bolt (41) and the inclined bottom mold (37); the inclined bottom mold (37) and the vertical side mold (38) are made of steel plate or aluminum alloy plate of the same material, and the vertical side mold (38) and the inclined bottom mold (37) are pre-connected firmly according to the depth of the scour pit (50) between the support piles.

6. The method for repairing seepage erosion pits between support piles in deep foundation pits with high groundwater levels according to claim 1, characterized in that: In step 6), the first airbag (43) and the second airbag (44) are both made of rubber sheets sewn into a closed cavity. Pipes connected to the external grouting device are respectively set on the first airbag (43) and the second airbag (44). The airbag filling material is water or mud. The first airbag (43) is provided with a bag weight (54) on the upper part, and the bag weight (54) is connected to the lower support plate (32) by the lower pressure control body (55).

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