A fast-deployed foundation pit enclosure support structure and a construction method thereof

Abstract

The application discloses a fast-deployed foundation pit enclosure support structure and a construction method thereof, and belongs to the technical field of foundation pit support, which comprises an enclosure structure, a guide structure and a support structure, the guide structure comprises a plurality of vertically arranged guide units, the guide unit comprises a plurality of rail tracks spliced at the head and tail, and the enclosure structure is provided with connecting supports which are detachably connected with the rail tracks; the support structure comprises a plurality of horizontally arranged support units, the support unit is fixed with a first support base at both ends, the bottom of the first support base is fixed with a vertically arranged driving hydraulic cylinder, the output end of the driving hydraulic cylinder is fixed with a second support base, and the first support base and the second support base are slidably connected with the corresponding rail tracks; the support unit is further provided with a servo hydraulic structure for supporting the enclosure structure at both ends; and the purpose lies in solving the problems of the existing foundation pit enclosure support structure, such as complicated process, long deployment period and the like.

Description

Technical Field

[0001] This invention belongs to the field of foundation pit support technology, specifically relating to a rapidly deployable foundation pit retaining support structure and its construction method. Background Technology

[0002] In the construction of deep foundation pits in cities, the construction speed of the internal support system directly restricts the progress of foundation pit excavation. Conventional foundation pit internal supports mainly adopt concrete supports or prefabricated steel pipe supports. During construction, it is necessary to carry out the work in layers and sections along with the foundation pit excavation. There are many on-site procedures such as component hoisting and positioning, node welding, bolt tightening, and prestressing tensioning.

[0003] Concrete supports require reinforcement binding, formwork erection, and concrete curing. They can only bear the support load after the strength reaches the standard, resulting in a long overall deployment cycle. The entire support erection process must be repeated for each layer of excavation, which takes up a long time. The subsequent dismantling work is also complicated, and the turnover efficiency of components is not high. Summary of the Invention

[0004] In view of this, the present invention discloses a rapidly deployable foundation pit retaining support structure and its construction method, the purpose of which is to solve the problems of complicated procedures and long deployment cycle of existing foundation pit retaining support structures.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A rapidly deployable foundation pit retaining support structure includes a retaining structure, a guiding structure, and a supporting structure. The guiding structure includes several vertically arranged guiding units, each of which includes several guide rails joined end-to-end. The retaining structure is provided with connecting supports that are detachably connected to the guide rails. The supporting structure includes several horizontally arranged supporting units. Each supporting unit has a first supporting seat fixed at both ends. A vertically arranged driving hydraulic cylinder is fixed at the bottom of each first supporting seat. A second supporting seat is fixed at the output end of each driving hydraulic cylinder. The first and second supporting seats are slidably connected to their corresponding guide rails, and locking pins are detachably connected between the first and second supporting seats and their corresponding guide rails. Servo hydraulic structures for supporting the retaining structure are also provided at both ends of the supporting units.

[0006] In this design, a first layer of concrete support is installed at the top of the excavation pit. The guide rails are quickly assembled using connecting supports, and the support units can be pre-assembled and hoisted for rapid deployment. Furthermore, a step-by-step drive method allows existing support units to be directly moved and lowered without the need for dismantling and re-hoisting, shortening the support erection period. After the support units are lowered, they are reinstalled above the guide rails, ensuring effective support throughout the entire height of the excavation pit and controlling lateral deformation. Simultaneously, all components are disassembled and reused, resulting in high turnover and adaptability to layered excavation conditions.

[0007] Furthermore, the servo hydraulic structure includes a servo hydraulic cylinder horizontally fixed on the support unit. Each servo hydraulic cylinder has a mounting base fixed to its output end, facing the corresponding guide rail. The mounting base has two connecting structures symmetrically arranged about the guide rail. Several vertically distributed connecting steel plates are provided on both sides of the guide rail. The connecting steel plates are embedded in the enclosure structure, and the connecting structures are detachably connected to the corresponding connecting steel plates.

[0008] In this scheme, the mounting base adopts a symmetrical double connection structure and connects with the pre-embedded connecting steel plate to avoid eccentric loads caused by single-point support, and the force transmission is more uniform and stable; while the enclosure structure is vertically arranged with multiple sets of connecting steel plates to adapt to the different elevation assembly requirements after the support unit is repositioned, and the disassembly and assembly are convenient; moreover, the connecting steel plate and the connecting parts are easy to disassemble and assemble, meeting the requirements of rapid deployment, and the overall components can be reused.

[0009] Furthermore, the mounting base has two symmetrically formed grooves parallel to the servo hydraulic cylinder. Each groove has a coaxially formed adjustment groove in its center. An annular block, sliding radially along the groove, is coaxially arranged within the adjustment groove, and several elastic support members are provided between the annular block and the adjustment groove. The connecting structure includes a connecting rod coaxially slidably connected within the annular block. One end of the connecting rod is provided with an elastic reset member between it and the groove. The other end of the connecting rod extends out of the groove and is detachably connected to the connecting steel plate. Several positioning rods are ball-jointed around the connecting rod. Positioning sleeves are coaxially slidably fitted onto the ends of the positioning rods. The ends of the positioning sleeves are ball-jointed to the mounting base, and fastening pins for locking the positioning rods are detachably connected to each positioning sleeve.

[0010] In this solution, the annular block, in conjunction with the elastic support, enables radial floating compensation, while the connecting rod, in conjunction with the elastic reset component, enables axial displacement compensation. This can offset the positional and installation deviations caused by the construction of the connecting steel plate and improve the success rate of the connection between the connecting rod and the connecting steel plate.

[0011] Furthermore, each of the connecting steel plates is fixed with a fixing ring adapted to the shape of the connecting rod. Each fixing ring has a flared guide ring coaxially fixed on its end face away from the connecting steel plate. Each fixing ring has a pin detachably connected to its side wall for locking the connecting rod.

[0012] Furthermore, both sides of the mounting base are hinged with inclined support rods, and the ends of the support rods are coaxially slidably fitted with support sleeves. The ends of the support sleeves are hinged to the support unit, and the support sleeves are detachably connected with positioning pins for locking the support rods.

[0013] Furthermore, reinforcing ribs are provided between the first support base and the support unit.

[0014] A construction method for a rapidly deployable foundation pit retaining support structure includes the following steps: S1. Construction preparation: During the construction of the retaining structure, the connecting supports and the connecting steel plates distributed vertically at intervals are pre-embedded simultaneously; the first concrete support is poured at the top of the foundation pit and cured to the design strength; the earthwork is excavated to the installation elevation of the support structure, and the installation position avoids the first concrete support. S2. Guide structure installation: Install the first layer of guide rails onto the corresponding connecting supports; S3. Pre-assembly and hoisting of the support unit: Pre-assemble the support unit, the first support base, the drive hydraulic cylinder, the second support base and the servo hydraulic structure into a support unit, and hoist the support unit to the guide rail position so that the first support base and the second support base slide in cooperation with the corresponding guide rail. S4. First layer support unit in place: First lock the first support seat, drive the hydraulic cylinder to move the second support seat down and lock it, then unlock the first support seat, drive the hydraulic cylinder to move the first support seat and support unit down to the working surface elevation and then lock it again. S5, Servo Support: Remove the fastening pin and positioning pin. The servo hydraulic cylinder drives the mounting base to feed. Two symmetrically arranged connecting rods on the mounting base are inserted into the fixing rings of the corresponding connecting steel plates under the guidance of the guide ring. Then, the connecting rods and fixing rings are locked by the pins, and the fastening pin is installed to lock the positioning rod to limit the movement of the connecting rods relative to the mounting base. After the servo hydraulic cylinder extends again to apply the required support force to the enclosure structure, the positioning pin is then installed to lock the support rod, thereby maintaining the magnitude of the support force applied to the enclosure structure. S6. Lower layer excavation and support repositioning: Excavate the next layer of soil downwards and install the guide rail for the second layer; sequentially pull out the positioning pin on the support sleeve, the pin on the fixing ring, and the fastening pin on the positioning sleeve. The servo hydraulic cylinder retracts, causing the mounting seat to retract, and the elastic reset component pushes the connecting rod to reset; pull out the locking pin of the second support seat, and use the drive hydraulic cylinder to drive the second support seat to move downwards along the guide rail to the correct position, then re-insert the locking pin to lock it. Then pull out the locking pin of the first support seat, and use the drive hydraulic cylinder to drive the first support seat and the entire support unit to move downwards along the guide rail to the next working elevation, and insert the locking pin to lock the first support seat. S7. Re-support and upper reinforcement: Repeat step S5 at the new elevation to reconnect and lock the connecting rod to the connecting steel plate at that elevation, and lock the positioning rod and support rod. The servo hydraulic cylinder reapplies the support pre-tightening force. Then, a new layer of support unit is hoisted and installed on the upper part of the guide rail to complete its positioning and locking and servo support operation. The new upper support unit and the original support unit that has been moved down are arranged vertically at intervals along the guide rail to jointly maintain the support constraint of the retaining structure within the entire height range of the foundation pit. S8. Cyclic operation: Continue to excavate the next layer of soil, repeating the operation process of steps S6 to S7, and repeating until the excavation of the foundation pit is completed. S9. Demolition and Recycling: After the foundation pit construction is completed, the servo hydraulic cylinders of each layer are unloaded layer by layer from top to bottom. The driving hydraulic cylinders drive each support unit to move upward along the guide rail, gradually dismantling the support structure and guide rail, and realizing the recycling and turnover of components.

[0015] Other advantages, objectives, and features of the invention will be set forth in the following description and will be apparent to those skilled in the art in some respects, or may be learned by practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0016] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration: Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a longitudinal sectional view of the connection between the connecting rod and the connecting steel plate in an embodiment of the present invention.

[0017] The following are the markings in the attached diagram: 1. Enclosure structure; 2. Guide rail; 3. Connecting support; 4. Support unit; 5. First support seat; 6. Drive hydraulic cylinder; 7. Second support seat; 8. Servo hydraulic cylinder; 9. Mounting seat; 10. Connecting steel plate; 11. Ring block; 12. Elastic support component; 13. Connecting rod; 14. Elastic reset component; 15. Positioning rod; 16. Positioning sleeve; 17. Fixing ring; 18. Guide ring; 19. Support rod; 20. Support sleeve; 21. Reinforcing rib; 22. Concrete support. Detailed Implementation

[0018] like Figures 1-3 As shown: A rapidly deployable foundation pit retaining support structure includes a retaining structure 1, a guide structure, and a support structure. The guide structure includes several vertically arranged guide units, each guide unit including several end-to-end guide rails 2. The retaining structure 1 is provided with connecting supports 3 that are detachably connected to the guide rails 2. The support structure includes several horizontally arranged support units 4. Each support unit 4 has a first support seat 5 fixed at both ends. The bottom of each first support seat 5 is fixed with a vertically arranged driving hydraulic cylinder 6. The output end of each driving hydraulic cylinder 6 is fixed with a second support seat 7. The first support seat 5 and the second support seat 7 are slidably connected to the corresponding guide rails 2, and the first support seat 5 and the second support seat 7 are detachably connected to the corresponding guide rails 2 with locking pins (a conventional technical means, so not shown in the figure). Each support unit 4 is also provided with a servo hydraulic structure for supporting the retaining structure 1 at both ends.

[0019] In this plan, during the early stage of foundation pit construction, the connecting support 3 is pre-embedded simultaneously during the construction of the retaining structure 1. The first concrete support 22 is poured at the top of the foundation pit. After the concrete support 22 has been cured to the design strength, the foundation pit excavation operation is carried out. The excavation is carried out to the installation elevation of this support structure. The installation position avoids the first concrete support 22 at the top to avoid spatial interference between components.

[0020] Connect the first layer guide rail 2 to the corresponding connecting support 3 on the enclosure structure 1; pre-assemble the support unit 4, the first support seat 5, the drive hydraulic cylinder 6, the second support seat 7 and the servo hydraulic structure into a support whole, and hoist it to the position of the guide rail 2 so that the first support seat 5, the second support seat 7 and the guide rail 2 form a sliding fit.

[0021] Insert a locking pin between the first support seat 5 and the guide rail 2 to lock the support unit 4. Drive the hydraulic cylinder 6 to drive the second support seat 7 to slide down the guide rail 2 a certain distance. Insert the locking pin to fix the second support seat 7. Then remove the locking pin on the first support seat 5. Drive the hydraulic cylinder 6 to drive the first support seat 5 to move vertically and adjust the support unit 4 to the corresponding excavation working face elevation. Insert the locking pin to lock the first support seat 5 and the guide rail 2. Operate the servo hydraulic structure at both ends of the support unit 4 to extend and press against the retaining structure 1 to apply support force and complete the support erection of this layer.

[0022] Continue excavating the next layer of earthwork. After the excavation is completed, remove the locking pin of the second support seat 7 of the first layer support unit 4. Use the driving hydraulic cylinder 6 to drive the second support seat 7 to move downward along the guide rail 2 into place. Reinsert the locking pin on the second support seat 7 to complete the locking. Then, use the driving hydraulic cylinder 6 to drive the first support seat 5 and the support unit 4 to move downward, so that the entire support moves down along the guide rail 2 to the next working position. The servo hydraulic structure continues to apply support to the retaining structure 1. At the upper position of the guide rail 2, hoist and install a new layer of support unit 4 to complete the positioning, locking and servo pre-force operation, and maintain the support constraint of the upper retaining structure 1 of the foundation pit.

[0023] The excavation then continues downwards to the next layer of earth, repeating the above-mentioned work process of "releasing the second support seat 7—moving down—locking the second support seat 7—moving the entire support down—adding a new support unit 4 to the upper part—excavating the next layer," repeating this cycle until the entire foundation pit excavation is completed. After the foundation pit excavation is completed, the servo hydraulic structures of each layer are unloaded in sequence, the locking pins are pulled out, and the drive hydraulic cylinder 6 drives each support unit 4 to move upwards along the guide rail 2, gradually dismantling the support structure and guide rail 2, realizing the recycling and reuse of components.

[0024] In this design, a first concrete support 22 is installed at the top of the foundation pit. The guide rail 2 is quickly assembled with the help of the connecting support 3, and the support unit 4 can be pre-assembled and hoisted for rapid deployment. In addition, a step-by-step driving method is adopted to allow the existing support unit 4 to be directly moved down without dismantling and re-hoisting, shortening the support erection period. After the support unit 4 is moved down, it is reinstalled above the guide rail 2, ensuring that the foundation pit maintains effective support throughout its entire height and controlling lateral deformation. At the same time, all components are disassembled and reused, with good turnover rate, and are suitable for layered excavation of foundation pits.

[0025] Furthermore, the servo hydraulic structure includes a servo hydraulic cylinder 8 horizontally fixed on the support unit 4. Each output end of the servo hydraulic cylinder 8 is fixed with a mounting seat 9 facing the corresponding guide rail 2. The mounting seat 9 has two connecting structures symmetrically arranged about the guide rail 2. Several vertically distributed connecting steel plates 10 are provided on both sides of the guide rail 2. The connecting steel plates 10 are embedded in the enclosure structure 1. The connecting structures are detachably connected to the corresponding connecting steel plates 10.

[0026] In this scheme, during the early stage of construction, when the connecting support 3 is pre-embedded in the retaining structure 1, the connecting steel plate 10 is pre-embedded simultaneously. After the support unit 4 is hoisted into place, the elevation is adjusted, and the locking pin is locked, the servo hydraulic cylinders 8 at both ends of the support unit 4 are activated to extend horizontally, driving the mounting seat 9 to move towards the retaining structure 1, so that the two connecting structures symmetrically arranged on the mounting seat 9 about the guide rail 2 are aligned with the pre-embedded connecting steel plate 10 at the corresponding elevation and connected and fixed. Then, the servo hydraulic cylinder 8 applies the preset pre-support force to realize the support of the retaining structure 1.

[0027] After the lower layer of earthwork is excavated, the connection between the connecting structure and the connecting steel plate 10 is released, and the servo hydraulic cylinder 8 is driven to retract. After the support unit 4 is moved down and repositioned as a whole, the connecting structure is reassembled and connected to the connecting steel plate 10 at that position, and the servo hydraulic cylinder 8 applies the support pre-tightening force again.

[0028] In this scheme, the mounting base 9 adopts a symmetrical double connection structure and docks with the pre-embedded connecting steel plate 10 to avoid eccentric loads caused by single-point support, and the force transmission is more uniform and stable; while the enclosure structure 1 is vertically arranged with multiple sets of connecting steel plates 10 to adapt to the different elevation assembly requirements after the support unit 4 is repositioned, and the disassembly and docking are convenient; and the disassembly and assembly between the connecting steel plate 10 and the connecting parts is convenient, meeting the requirements of rapid deployment, and the overall components can be reused.

[0029] Furthermore, the mounting base 9 has two symmetrically arranged sliding grooves parallel to the servo hydraulic cylinder 8. Each sliding groove has a coaxially arranged adjustment groove in its center. An annular block 11, which slides radially along the sliding groove, is coaxially arranged within the adjustment groove. Several elastic support members 12 are arranged between the annular block 11 and the adjustment groove. The connection structure includes a connecting rod 13 coaxially slidably connected within the annular block 11. One end of the connecting rod 13 is provided with an elastic reset member 14 between it and the sliding groove. The other end of the connecting rod 13 extends out of the sliding groove and is detachably connected to the connecting steel plate 10. Several positioning rods 15 are ball-jointed to the periphery of the connecting rod 13. Positioning sleeves 16 are coaxially slidably fitted onto the ends of the positioning rods 15. The ends of the positioning sleeves 16 are ball-jointed to the mounting base 9. Each positioning sleeve 16 is detachably connected with a fastening pin for locking the positioning rod 15 (a conventional technique, therefore not shown in the figure).

[0030] In this scheme, after the support unit 4 is hoisted and locked into place, the fastening pin is removed, and the servo hydraulic cylinder 8 extends horizontally to drive the mounting seat 9 to move towards the enclosure structure 1. The connecting rod 13 moves close to the pre-embedded connecting steel plate 10 along with the mounting seat 9. When the end of the connecting rod 13 contacts the connecting steel plate 10, the connecting rod 13 slides along the inside of the annular block 11 into the inner side of the slide groove under the action of the reaction force, and the elastic reset member 14 is compressed to compensate for the distance difference between the two connecting rods 13 and the connecting steel plate 10. The annular block 11 can achieve radial floating compensation with the help of the elastic support member 12 inside the adjustment groove to adapt to the installation position deviation of the connecting steel plate 10. At the same time as the connecting rod 13 is displaced, the positioning rod 15 slides relative to the positioning sleeve 16. The ball joints at both ends of the positioning rod 15 and the positioning sleeve 16 are used to adaptively adjust the angle to offset the position deviation during the alignment process.

[0031] After the end of the connecting rod 13 is aligned and fixed with the connecting steel plate 10, the fastening pin is inserted into the positioning sleeve 16 to lock the positioning rod 15, thus locking the position of the connecting rod 13. Then, the servo hydraulic cylinder 8 applies a preset pre-support force to support the enclosure structure 1.

[0032] In this scheme, the annular block 11, together with the elastic support 12, can achieve radial floating compensation, and the connecting rod 13, together with the elastic reset component 14, can achieve axial displacement compensation. This can offset the position and installation deviations caused by the construction of the connecting steel plate 10 and improve the success rate of docking between the connecting rod 13 and the connecting steel plate 10.

[0033] Furthermore, each of the connecting steel plates 10 is fixed with a fixing ring 17 that is adapted to the shape of the connecting rod 13. Each fixing ring 17 has a flared guide ring 18 coaxially fixed on its end face away from the connecting steel plate 10. Each fixing ring 17 has a pin for locking the connecting rod 13 that can be detachably connected to its side wall (this is a conventional technical means and therefore not shown in the figure).

[0034] In this scheme, after the support unit 4 is in place, the servo hydraulic cylinder 8 drives the mounting base 9 to move towards the enclosure structure 1, and the connecting rod 13 moves forward accordingly; the front-end trumpet-shaped guide ring 18 can guide and correct the connecting rod 13 over a wide range, so that the connecting rod 13 can slide precisely into the fixed ring 17. With the radial floating of the annular block 11 and the elastic support 12, and the axial compensation of the elastic reset member 14, the installation deviation is adaptively offset; after the connecting rod 13 is fully inserted into the fixed ring 17, the connecting rod 13 is locked through the pin on the side wall of the fixed ring 17, thus completing the rigid connection and fixation between the connecting rod 13 and the connecting steel plate 10.

[0035] Furthermore, both sides of the mounting base 9 are hinged with inclined support rods 19, and the ends of the support rods 19 are slidably fitted with support sleeves 20. The ends of the support sleeves 20 are hinged to the support unit 4, and the support sleeves 20 are detachably connected with positioning pins for locking the support rods 19.

[0036] In this solution, after removing the positioning pin and controlling the extension of the servo hydraulic cylinder 8 to apply support force to the enclosure structure 1, the positioning pin is then installed to lock the support rod 19. The mechanical locking method is used to maintain the magnitude of the support force applied to the enclosure structure 1, preventing the support force from attenuating due to oil pressure fluctuations or pressure leakage of the servo hydraulic cylinder 8, and maintaining the stability of the support force on the enclosure structure 1.

[0037] Furthermore, reinforcing ribs 21 are provided between the first support base 5 and the support unit 4.

[0038] By setting reinforcing ribs 21, the connection strength between the first support base 5 and the support unit 4 is enhanced.

[0039] A construction method for a rapidly deployable foundation pit retaining support structure, characterized by the following steps: S1. Construction preparation: During the construction of the retaining structure 1, the connecting support 3 and the connecting steel plates 10 distributed vertically at intervals are pre-embedded simultaneously; the first concrete support 22 is poured at the top of the foundation pit and cured to the design strength; the earthwork is excavated to the installation elevation of the support structure, and the installation position avoids the first concrete support 22. S2. Guide structure installation: Install the first layer guide rail 2 onto the corresponding connecting steel plate 10; S3. Pre-assembly and hoisting of the support unit: The support unit 4, the first support seat 5, the drive hydraulic cylinder 6, the second support seat 7 and the servo hydraulic structure are pre-assembled into a support unit. The support unit is then hoisted to the position of the guide rail 2, so that the first support seat 5 and the second support seat 7 are in sliding fit with the corresponding guide rail 2. S4. First layer support unit in place: First lock the first support seat 5, drive the hydraulic cylinder 6 to move the second support seat 7 down and lock it, then unlock the first support seat 5, drive the hydraulic cylinder 6 to move the first support seat 5 and support unit 4 down to the working surface elevation and then lock it again. S5, Servo Support: Remove the fastening pin and positioning pin, the servo hydraulic cylinder 8 drives the mounting base 9 to feed, and the two symmetrically arranged connecting rods 13 on the mounting base 9 are inserted into the fixing ring 17 of the corresponding connecting steel plate 10 under the guidance of the guide ring 18. Then, the connecting rod 13 and the fixing ring 17 are locked by the pin, and the fastening pin is installed to lock the positioning rod 15 to limit the movement of the connecting rod 13 relative to the mounting base 9. After the servo hydraulic cylinder 8 extends again to apply the required support force to the enclosure structure 1, the positioning pin is then inserted to lock the support rod 19, so as to maintain the magnitude of the support force applied to the enclosure structure 1. S6. Lower layer excavation and support repositioning: Excavate the next layer of soil downwards and install the guide rail 2 of the second layer; sequentially pull out the positioning pin on the support sleeve 20, the pin on the fixing ring 17, and the fastening pin on the positioning sleeve 16. The servo hydraulic cylinder 8 retracts, driving the mounting seat 9 to retract. The elastic reset component 14 pushes the connecting rod 13 to reset; pull out the locking pin of the second support seat 7, and use the driving hydraulic cylinder 6 to drive the second support seat 7 to move downwards along the guide rail 2 to the position, and then re-insert the locking pin to lock it. Then pull out the locking pin of the first support seat 5, and use the driving hydraulic cylinder 6 to drive the first support seat 5 and the support unit 4 to move downwards along the guide rail 2 to the next working elevation. Insert the locking pin to lock the first support seat 5. S7. Re-support and upper reinforcement: Repeat step S5 at the new elevation to reconnect and lock the connecting rod 13 to the connecting steel plate 10 at that elevation, and lock the positioning rod 15 and the support rod 19. The servo hydraulic cylinder 8 reapplies the support pre-tightening force. Then, a new layer of support unit 4 is hoisted and installed on the upper part of the guide rail 2 to complete its positioning and locking and servo support operation. The new upper support unit 4 and the original support unit 4 that has been moved down are arranged vertically at intervals along the guide rail 2 to jointly maintain the support constraint of the retaining structure 1 within the entire height range of the foundation pit. S8. Cyclic operation: Continue to excavate the next layer of soil, repeating the operation process of steps S6 to S7, and repeating until the excavation of the foundation pit is completed. S9. Demolition and Recycling: After the foundation pit construction is completed, the servo hydraulic cylinders 8 of each layer are unloaded layer by layer from top to bottom. The driving hydraulic cylinders 6 drive each support unit 4 to move upward along the guide rail 2, gradually dismantling the support structure and guide rail 2, so as to realize the recycling and turnover of components.

[0040] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A rapidly deployable foundation pit retaining support structure, characterized in that: The enclosure includes an enclosure structure, a guide structure, and a support structure. The guide structure includes several vertically arranged guide units, each guide unit including several guide rails joined end-to-end. The enclosure structure is provided with connecting supports that are detachably connected to the guide rails. The support structure includes several horizontally arranged support units, each support unit having a first support seat fixed at both ends. A vertically arranged driving hydraulic cylinder is fixed at the bottom of each first support seat, and a second support seat is fixed at the output end of each driving hydraulic cylinder. The first and second support seats are slidably connected to their corresponding guide rails, and locking pins are detachably connected between the first and second support seats and their corresponding guide rails. Servo hydraulic structures for supporting the enclosure structure are also provided at both ends of the support unit.

2. The rapidly deployable foundation pit retaining support structure according to claim 1, characterized in that: The servo hydraulic structure includes a servo hydraulic cylinder horizontally fixed on a support unit. Each servo hydraulic cylinder has a mounting base fixed to its output end, facing the corresponding guide rail. The mounting base has two connecting structures symmetrically arranged about the guide rail. Several vertically distributed connecting steel plates are arranged on both sides of the guide rail. The connecting steel plates are embedded in the enclosure structure, and the connecting structures are detachably connected to the corresponding connecting steel plates.

3. The rapidly deployable foundation pit retaining support structure according to claim 2, characterized in that: The mounting base has two symmetrical grooves parallel to the servo hydraulic cylinder. Each groove has a coaxial adjustment groove in its center. An annular block, sliding radially along the groove, is coaxially arranged within the adjustment groove, and several elastic support members are provided between the annular block and the adjustment groove. The connecting structure includes a connecting rod coaxially slidably connected within the annular block. One end of the connecting rod is provided with an elastic reset member between it and the groove. The other end of the connecting rod extends out of the groove and is detachably connected to a connecting steel plate. Several positioning rods are ball-jointed around the connecting rod. Positioning sleeves are coaxially slidably fitted onto the ends of the positioning rods. The ends of the positioning sleeves are ball-jointed to the mounting base, and fastening pins for locking the positioning rods are detachably connected to each positioning sleeve.

4. The rapidly deployable foundation pit retaining support structure according to claim 3, characterized in that: Each of the connecting steel plates is fixed with a fixing ring that matches the shape of the connecting rod. Each fixing ring has a flared guide ring coaxially fixed on its end face away from the connecting steel plate. Each fixing ring has a pin detachably connected to its side wall for locking the connecting rod.

5. A rapidly deployable foundation pit retaining support structure according to claim 4, characterized in that: Both sides of the mounting base are hinged with inclined support rods, and the ends of the support rods are coaxially slidably fitted with support sleeves. The ends of the support sleeves are hinged to the support unit, and the support sleeves are detachably connected with positioning pins for locking the support rods.

6. The rapidly deployable foundation pit retaining support structure according to claim 5, characterized in that: Reinforcing ribs are provided between the first support base and the support unit.

7. The construction method for a rapidly deployable foundation pit retaining support structure according to claim 6, characterized in that, Includes the following steps: S1. Construction preparation: During the construction of the retaining structure, the connecting supports and the connecting steel plates distributed vertically at intervals are pre-embedded simultaneously; the first concrete support is poured at the top of the foundation pit and cured to the design strength; the earthwork is excavated to the installation elevation of the support structure, and the installation position avoids the first concrete support. S2. Guide structure installation: Install the first layer of guide rails onto the corresponding connecting supports; S3. Pre-assembly and hoisting of the support unit: Pre-assemble the support unit, the first support base, the drive hydraulic cylinder, the second support base and the servo hydraulic structure into a support unit, and hoist the support unit to the guide rail position so that the first support base and the second support base slide in cooperation with the corresponding guide rail. S4. First layer support unit in place: First lock the first support seat, drive the hydraulic cylinder to move the second support seat down and lock it, then unlock the first support seat, drive the hydraulic cylinder to move the first support seat and support unit down to the working surface elevation and then lock it again. S5, Servo Support: Remove the fastening pin and positioning pin. The servo hydraulic cylinder drives the mounting base to feed. Two symmetrically arranged connecting rods on the mounting base are inserted into the fixing rings of the corresponding connecting steel plates under the guidance of the guide ring. Then, the connecting rods and fixing rings are locked by the pins, and the fastening pin is installed to lock the positioning rod to limit the movement of the connecting rods relative to the mounting base. After the servo hydraulic cylinder extends again to apply the required support force to the enclosure structure, the positioning pin is then installed to lock the support rod, thereby maintaining the magnitude of the support force applied to the enclosure structure. S6. Lower layer excavation and support repositioning: Excavate the next layer of soil downwards and install the guide rail for the second layer; sequentially pull out the positioning pin on the support sleeve, the pin on the fixing ring, and the fastening pin on the positioning sleeve. The servo hydraulic cylinder retracts, causing the mounting seat to retract, and the elastic reset component pushes the connecting rod to reset; pull out the locking pin of the second support seat, and use the drive hydraulic cylinder to drive the second support seat to move downwards along the guide rail to the correct position, then re-insert the locking pin to lock it. Then pull out the locking pin of the first support seat, and use the drive hydraulic cylinder to drive the first support seat and the entire support unit to move downwards along the guide rail to the next working elevation, and insert the locking pin to lock the first support seat. S7. Re-support and upper reinforcement: Repeat step S5 at the new elevation to reconnect and lock the connecting rod to the connecting steel plate at that elevation, and lock the positioning rod and support rod. The servo hydraulic cylinder reapplies the support pre-tightening force. Then, a new layer of support unit is hoisted and installed on the upper part of the guide rail to complete its positioning and locking and servo support operation. The new upper support unit and the original support unit that has been moved down are arranged vertically at intervals along the guide rail to jointly maintain the support constraint of the retaining structure within the entire height range of the foundation pit. S8. Cyclic operation: Continue to excavate the next layer of soil, repeating the operation process of steps S6 to S7, and repeating until the excavation of the foundation pit is completed. S9. Demolition and Recycling: After the foundation pit construction is completed, the servo hydraulic cylinders of each layer are unloaded layer by layer from top to bottom. The driving hydraulic cylinders drive each support unit to move upward along the guide rail, gradually dismantling the support structure and guide rail, and realizing the recycling and turnover of components.

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