Foundation pit support system for foundation pit construction

Abstract

The invention relates to the field of foundation pit supporting, and particularly discloses a foundation pit support system for foundation pit construction, which comprises a plurality of stirring piles and prefabricated plate piles arranged on the stirring piles, or a plurality of high-pressure jet grouting piles and prefabricated concrete sheet piles arranged on the high-pressure jet grouting piles; the main supporting piece is arranged in the middle of the foundation pit; the multiple auxiliary supporting pieces are evenly distributed on the edge of the foundation pit; the connecting piece is arranged between the main supporting piece and the auxiliary supporting piece; the flexible blocking piece is connected between any two auxiliary supporting pieces and provided with a blocking face matched with the inner wall of the foundation pit. And a water storage chamber is arranged in the flexible blocking piece. The flexible blocking piece makes contact with the inner wall of the foundation pit, water is injected into the water storage cavity so that the flexible blocking piece can expand till the blocking face of the flexible blocking piece can be completely attached to the inner wall of the foundation pit, the inner wall of the foundation pit is prevented from partially collapsing, and the situation that the flexible blocking piece is crushed and consequently the enclosure effect is reduced is prevented.

Description

Technical Field

[0001] This application relates to the field of foundation pit support, and in particular to a foundation pit retaining system for foundation pit construction. Background Technology

[0002] Currently, the main method of foundation pit protection is to support the inner wall of the foundation pit to prevent it from collapsing due to external environmental factors or the soil itself, especially during construction work, which may be caused by work stoppages at night or due to special weather conditions.

[0003] A related Chinese patent application (CN202011359393.7) proposes selecting different numbers of columns based on the size of the foundation pit, pulling the shielding cloth out onto a wrapping roller, and fixing connecting rods to fixing grooves on adjacent columns using fasteners, thereby enabling the shielding cloth to effectively enclose the foundation pit. The main disclosure involves using a flexible material to surround the columns, forming a ring-shaped area whose shape closely matches the inner wall of the foundation pit.

[0004] Regarding the aforementioned technologies, the inventors believe that the following defects exist: The way the shielding cloth is wrapped around the column to limit the shape of the shielding cloth can only limit the shape and position of the shielding cloth relative to the pit from above. However, the inner wall of the pit is not a wall perpendicular to the ground. Due to construction reasons, the inner wall of the pit is uneven, which will cause a gap between the shielding cloth and the inner wall of the pit. The gaps represent the space where the soil on the inner wall of the foundation pit can partially collapse, making it difficult to completely prevent the inner wall of the foundation pit from collapsing. After some of the soil on the inner wall of the foundation pit collapses, it will press on the retaining cloth, which can easily increase the external force on the retaining cloth and cause it to be crushed, thus reducing the effectiveness of the foundation pit protection. Summary of the Invention

[0005] To address the problem of difficulty in completely preventing the collapse of the inner wall of a foundation pit, this application provides a foundation pit support system for foundation pit construction.

[0006] The foundation pit support system for foundation pit construction provided in this application adopts the following technical solution: A foundation pit retaining system for foundation pit construction includes multiple mixing piles and precast sheet piles installed on the multiple mixing piles; the multiple mixing piles are connected end-to-end to form a waterproof construction area; the foundation pit is located in the waterproof construction area; or multiple high-pressure jet grouting piles and precast concrete sheet piles installed on the high-pressure jet grouting piles; the multiple high-pressure jet grouting piles and precast concrete sheet piles are connected end-to-end to form the waterproof construction area, and the foundation pit is located in the waterproof construction area; the retaining system further includes: a main support member, located in the middle of the foundation pit; multiple secondary support members, evenly distributed on the edge of the foundation pit; a connector, located between the main support member and the secondary support members; a flexible baffle, connected between any two secondary support members, and having a baffle surface that mates with the inner wall of the foundation pit; the flexible baffle has a water storage chamber; and a driving member for injecting and extracting water into and from the water storage chamber, so that the flexible baffle expands until the baffle surface fits against the inner wall of the foundation pit.

[0007] By adopting the above technical solution, the expansion of the flexible retaining member allows it to completely conform to the inner wall of the pit, preventing any space for partial collapse of the pit's inner wall. This completely avoids pit collapse during the retaining process. Better pit maintenance and prevention of collapse are achieved because the conversion of gravitational potential energy into kinetic energy causes the force exerted by the collapsing soil on the flexible retaining member to exceed the static supporting force between the pit's inner wall and the flexible retaining member, thus preventing the flexible retaining member from being easily crushed. This better ensures the stability of the pit retaining structure.

[0008] Optionally, the secondary support includes a support rod and a slot disposed on the support rod; the flexible stop includes a flexible body having the water storage chamber and a pair of insert rods fixedly disposed on both sides of the flexible body; the insert rods are inserted into the slot.

[0009] By adopting the above technical solutions, flexible bodies can be more easily disassembled and installed on load-bearing rods, reducing transportation costs and increasing installation efficiency.

[0010] Optionally, both the slot and the insert rod have polygonal cross-sections; the size of the insert rod is smaller than the size of the slot, and the circumcircle diameter of the insert rod is larger than the incircle diameter of the slot; the insert rod is also provided with a groove, which communicates with the slot; the insert rod or the insert rod and part of the flexible body are located in the slot, and the flexible body part is located in the groove; when the insert rod and part of the flexible body are located in the slot, the flexible body part is wrapped around the insert rod.

[0011] By adopting the above technical solution, the flexible body can be wrapped around the insert rod, thereby reducing the distance between the two insert rods of the flexible body and ensuring that the insert rod is inserted into the slot. This makes it easier to adjust the length of the flexible body to accommodate the error in the installation position of the secondary support, which can improve the installation and reduce the installation difficulty.

[0012] Optionally, the connector includes: a connecting rod, a fixing plate fixedly disposed at both ends of the connecting rod, and a fixing block having a slot, the shape of the slot matching the fixing plate; the fixing plate slidingly engaging with the inner wall of the slot; two fixing blocks are provided, one of which is connected to the main support member, and the other of which is connected to the secondary support member.

[0013] By adopting the above technical solution, the hinge is achieved by directly using sliding friction, which better ensures the stability of the hinge between the connecting rod and the main and secondary support components. This avoids the situation where the hinge strength is limited by size, making it difficult to balance size and strength, which can easily lead to hinge damage.

[0014] Optionally, the fixed disk has protrusions at both ends; the fixed block has a limiting hole, the protrusion is located in the limiting hole, and there is a movable gap between the outer wall of the protrusion and the inner wall of the limiting hole.

[0015] By adopting the above technical solution, the protrusion is designed to allow the connecting rod to be better installed between the main support and the secondary support, thus preventing the connecting rod from falling off between the main support and the secondary support.

[0016] Optionally, the outer wall of the fixed disk or the inner wall of the slot may be provided with multiple rollers or balls.

[0017] Optionally, a plurality of insert rods are provided between the two sides of the flexible body, and the insert rods are located on the outer wall of the flexible body; a plurality of bearing rods are provided along the contour trajectory of the foundation pit; the plurality of insert rods are respectively inserted into the slots of the plurality of bearing rods; a pile of insert rods at both ends of the flexible body are fixedly connected so that the flexible body forms an annular closed wall area.

[0018] By adopting the above technical solution, the flexible body itself can be a whole, and the annular closed wall area enclosed by the flexible body can be completely attached to the inner wall of the foundation pit, avoiding any gaps between the flexible body and the inner wall of the foundation pit, thus better protecting the inner wall of the foundation pit.

[0019] Optionally, the lower part of the flexible body is provided with an elastic extension; the extension is connected to the outer wall of the flexible body; the extension has an elastic chamber, and the driving member is also used to inject water into the elastic chamber; the outer wall of the extension is provided with a plurality of protruding cones for insertion into the bottom surface of the foundation pit.

[0020] By adopting the above technical solution, the extension body is used to increase the weight by injecting water, thereby limiting the flexible body from below and preventing the flexible body from shifting.

[0021] Optionally, the driving component includes: a water pump, a water storage bag, a first connecting pipe connecting the water pump and the water storage bag, and a second connecting pipe connecting the water storage bag and the water storage chamber; the main support component includes: a fixed rod and a pressure plate slidably disposed on the fixed rod; the connecting member is hinged between the pressure plate and the secondary support component; the water storage bag is disposed above the pressure plate; the water storage bag and the second connecting pipe are connected through a pressure relief valve.

[0022] By adopting the above technical solution, while the water pump injects water into the flexible body, the water is first injected into the water storage bag. The water storage bag uses its own weight to apply downward pressure to the pressure plate, so that the pressure plate applies an external force to the auxiliary support through the connector to press against the inner wall of the pit, thus better pressing against the pit and supporting it.

[0023] Optionally, the foundation pit retaining system further includes: connecting ropes; multiple connecting ropes are provided, and the multiple connecting ropes are tensioned between the main support and the mixing pile.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. Utilize flexible baffles to contact the inner wall of the foundation pit, and inject water into the water storage chamber to expand the flexible baffles until the baffles are completely in contact with the inner wall of the foundation pit, to prevent partial collapse of the inner wall of the foundation pit and to prevent the flexible baffles from being crushed, which would reduce the retaining effect. 2. By using the main support components and connectors, the position of the secondary support components can be better stabilized, preventing the secondary support components from shifting or tilting under external forces when the foundation pit shows signs of collapse. 3. By utilizing the fixed plate and slot design, the ultimate strength of the connectors under external forces is improved, thus enhancing the protection effect on the foundation pit; 4. By utilizing the extension body, the lower part of the flexible body can be actively supported, preventing deformation of the lower part of the flexible body from causing incomplete contact with the inside of the foundation pit; 5. By utilizing the water storage bag, when water is injected into the flexible body, a downward force is applied to the pressure plate, causing the pressure plate to exert an external force against the inner wall of the pit through the connecting parts, thereby increasing the effect of pit protection. Attached Figure Description

[0025] Figure 1 This is an overall schematic diagram according to an embodiment of this application; it mainly shows a schematic diagram of the overall structure of this application actually supporting the foundation pit; Figure 2 This is a structural diagram of a part of an embodiment, mainly showing the overall structure of this application; Figure 3 This is a structural schematic diagram of a part of the embodiment, mainly showing the structure of the main support, secondary support, connector and some surrounding parts; Figure 4 This is a structural schematic diagram of a part of the embodiment, mainly showing the structure of the main support member and some surrounding parts; Figure 5 This is a structural schematic diagram of a part of the embodiment, mainly showing the structure of the secondary support member and the flexible stop member; Figure 6 This is a structural schematic diagram of a part of the embodiment, mainly showing the structure of the secondary support and the insertion rod; Figure 7 This is a structural schematic diagram of a part of the embodiment, mainly showing the structure of the secondary support member; Figure 8 This is a structural schematic diagram of a part of the embodiment, mainly showing the structure of the connector and some surrounding parts; Figure 9 This is a structural schematic diagram of a part of the embodiment, mainly showing the structure of the fixing block and some surrounding parts; Figure 10 This is a structural diagram of a part of an embodiment, mainly showing the structure of the fixing block; Figure 11 This is a structural schematic diagram of a part of an embodiment, mainly showing the exploded structure of the secondary support member; Figure 12 This is a structural schematic diagram as part of an embodiment, mainly showing the structure of the flexible body and the rigid space frame; Figure 13 This is a structural schematic diagram as part of an embodiment, mainly showing the structure of multiple inserts between the two sides of the flexible body; Figure 14 This is a structural schematic diagram as part of an embodiment, mainly showing the structure of the flexible body and the extension body; Figure 15 This is a structural diagram of a part of an embodiment, mainly showing the structure of the fixing plate; Figure 16 This is a structural schematic diagram of a part of the embodiment, mainly showing the structure of the mixing pile and the precast sheet pile; Figure 17 This is a structural schematic diagram as part of the embodiment, mainly showing the structure of high-pressure jet grouting piles and precast concrete sheet piles.

[0026] Figure label: 1. Mixing pile; 11. Precast sheet pile; 12. High-pressure jet grouting pile; 13. Precast concrete sheet pile; 2. Main support component; 21. Fixing rod; 22. Pressure plate; 3. Secondary support component; 31. Bearing rod; 32. Clamp; 321. Slot; 322. Groove; 33. Tapered rod; 34. Pedal; 35. Connecting block; 351. Mounting groove; 4. Connector; 41. Connecting rod; 42. Fixing plate; 43. Fixing block; 431. Slot; 432. Limiting hole; 44. Protrusion; 5. Flexible stop; 51. Flexible body; 52. Insert rod; 53. Extension body; 6. Drive unit; 61. Water pump; 62. Water storage bag; 63. First connecting pipe; 64. Second connecting pipe; 7. Connect the ropes; 8. Rigid space frame; 9. Fixing plate; 91. Groove; 92. Retention groove; 93. Retention chamber. Detailed Implementation

[0027] The following is in conjunction with the attached figures. Figures 1-15 This application will be described in further detail.

[0028] This application discloses a foundation pit support system for foundation pit construction.

[0029] Example 1: A foundation pit retaining system for foundation pit construction includes multiple high-pressure jet grouting piles and precast concrete sheet piles set on the high-pressure jet grouting piles; the multiple high-pressure jet grouting piles and the precast concrete sheet piles are connected end to end to form a waterproof construction area, the foundation pit is located in the waterproof construction area, and the precast concrete sheet piles are H-shaped (the concrete is C60 and equipped with steel strands).

[0030] The construction process is as follows: I. Pre-construction preparation ① Site leveling and treatment Remove obstacles from the site, compact or replace weak foundations, and ensure the bearing capacity requirements when the static pile driver moves.

[0031] ② Measurement, layout, and positioning Lay out the pile positions according to the design drawings, use a total station or GPS to locate them, and mark the pile position range with white lime. Set up axis control piles and leveling benchmarks.

[0032] ③ Material and equipment inspection Inspect the quality of precast concrete sheet piles, including concrete strength and appearance. Verify equipment such as pile drivers, cranes, and pressure gauges.

[0033] II. Pile driver positioning and pile lifting ① Pile driver installation and commissioning Install the pile driver according to the instructions, adjust the counterweight balance, ensure the platform is level, and tilt the gantry slightly by 15° to facilitate pile lifting.

[0034] Align the center of the pile driver with the pile position, and start the hydraulic cylinder to fix the platform.

[0035] ② Hoisting and Pile Driving The sheet pile is lifted using the hook on the precast sheet pile and gently placed into the pile position.

[0036] III. Pile Driving and Straightening ① Verticality correction After initial compaction to 50cm, use a theodolite or plumb bob to check the verticality in both directions; the deviation should be ≤0.5%. If the pile body is tilted, the pile driver position needs to be adjusted or the pile needs to be re-inserted; forced correction is strictly prohibited.

[0037] ② Static pressure pile driving Control the pile driving speed to ≤2m / min, and record the pressure gauge reading simultaneously with the penetration depth. Reduce the speed to 1m / min when encountering hard layers. The pile driving sequence should follow the principle of "deep first, shallow second; large first, small second; from the center outwards" to reduce soil squeezing effect.

[0038] IV. Construction of high-pressure jet grouting piles After the high-pressure jet grouting pile construction has a working surface, construction is carried out in the gap of the precast concrete sheet pile splicing. The depth is based on the design requirements. The drill rod is continuously rotated (15-20 r / min) and lifted at a uniform speed (10-20 cm / min). The jetting pressure and flow rate need to be stable to prevent pile breakage.

[0039] The above scheme mainly consists of two processes: precast concrete sheet piles and high-pressure jet grouting piles. First, the precast concrete sheet piles are driven using a static pressure method to ensure accurate positioning and verticality. The splicing heads and slots of the precast concrete sheet piles are aligned, and the piles are driven in sequence. Then, high-pressure jet grouting piles are constructed at the joint of two precast concrete sheet piles.

[0040] Compared to bored piles, the use of precast concrete sheet piles in foundation pit support has the following advantages: 1. Fast construction speed and short construction period Precast concrete sheet piles can be directly transported to the site for installation after being prefabricated in the factory, without the need for on-site pouring and curing. The construction process is simple and it is especially suitable for projects with tight schedules.

[0041] 2. Good soil protection and water-stopping effect between piles In this scheme, after the splicing clips and splicing slots of the precast concrete sheet piles are aligned, the precast concrete sheet piles are basically seamlessly connected to each other, which is much smaller than the gap between cast-in-place piles. In addition, the high-pressure jet grouting piles constructed at the splicing joint further ensure that there will be no soil or water leakage at the joint.

[0042] 3. High stiffness and small deformation Precast concrete sheet piles have high cross-sectional stiffness, which can effectively control the deformation of the foundation pit sidewalls, and are especially suitable for projects that require strict deformation control.

[0043] 4. Excellent durability and economy Precast concrete sheet piles have strong corrosion resistance, long service life, and relatively low cost.

[0044] 5. Highly adaptable and applicable to a wide range of scenarios. Precast concrete sheet piles are suitable for shallow to medium-depth foundation pits (such as 5-10 meters). When used in conjunction with support structures, they can be effective in deeper foundation pits, especially in soft soil or areas requiring rapid construction.

[0045] Example 2: A foundation pit retaining system for foundation pit construction includes multiple mixing piles 1 and precast sheet piles set on the multiple mixing piles 1; the multiple mixing piles 1 are connected end to end to form a waterproof construction area; the foundation pit is located in the waterproof construction area. The precast sheet piles are H-shaped precast concrete sheet piles (using C60 concrete and equipped with steel strands), and the mixing piles 1 are preferably triaxial mixing piles 1 manufactured using a triaxial mixing method.

[0046] The construction process is as follows: I. Construction Preparation ① Site clearing and surveying Remove obstacles from the construction area, level and compact the site to ensure the stability of the piling machine's working surface.

[0047] According to the design drawings, the measurement and layout are carried out to determine the center line of the pile position and the position of the guide trench, and permanent positioning marks are set.

[0048] ② Equipment commissioning and test piling Debug and test equipment such as the triaxial mixing pile machine and crane to ensure that the drill bit and grouting system are operating normally.

[0049] Conduct test piles (usually no fewer than 6) to verify parameters such as drilling speed, grouting pressure, and cement content, and optimize the construction plan. II. Guide trench excavation and directional positioning. ① Excavation of the guide trench Excavate a guide trench along the direction of the foundation pit, with a width of about 1-1.2 meters and a depth of 0.5-1.5 meters, to guide the insertion of steel profiles and store the replaced cement soil.

[0050] Remove underground obstacles from the guide channel and, if necessary, replace with dense material to prevent collapse.

[0051] ② Setting of guide steel and guide rail Guide positioning steel (such as No. 10 channel steel or I-beam) is laid on both sides of the guide groove and fixed on the guide rail to ensure accurate positioning of the drilling rig (plane error ≤ 2cm).

[0052] Set positioning clips or guide frames to control the verticality of the steel section during insertion (deviation ≤ 1 / 200).

[0053] III. Construction of Tri-axis Mixing Piles ① Drilling and shotcreting After the piling machine is in place, the drill bit sinks at a speed of 0.5-1m / min, and cement slurry (water-cement ratio 1:1.0 to 1:1.15) is injected simultaneously to fully mix the cement with the soil.

[0054] When traversing sand or silt layers, reduce the drilling speed to ≤0.8m / min to avoid hole collapse; after reaching the bottom of the pile, stop grouting for 20 seconds to enhance the bottom strength.

[0055] ② Re-stirring and lifting Raise the drill rod to the design elevation at a speed of ≤1.2m / min, and spray grout and mix it while raising the rod to ensure that the pile body is uniform and dense.

[0056] Repeat drilling and stirring 2-3 times to eliminate stratification or mud inclusions and improve water-stopping performance (permeability coefficient up to 10). -7 (cm / s).

[0057] IV. Insertion and Fixing of Precast Concrete Sheet Piles ① Lifting and Insertion The precast concrete sheet piles are lifted using a power-matched crane. Within 30 minutes of the mixing pile construction, the precast concrete sheet piles are inserted and lowered vertically using their own weight, with mechanical assistance used if necessary. Verticality is monitored in real time, with a deviation ≤0.5% and an insertion depth error ±50mm.

[0058] ② Temporary fixation When the crane places the precast concrete sheet pile into the three-axis pile body, it should prevent deviation and correct it in time. The fixation should be released after the pile body has hardened.

[0059] This scheme mainly consists of two processes: precast concrete sheet piles and triaxial mixing piles. First, following the construction process of triaxial mixing piles, triaxial mixing piles are used at the support location. Sheet piles are inserted into each set of piles, with one pile inserted every other hole.

[0060] Compared to bored piles, the use of precast sheet piles in foundation pit support has the following advantages: 1. Fast construction speed and short construction period Precast sheet piles can be directly transported to the site for installation after being prefabricated in the factory, without the need for on-site pouring and curing. The construction process is simple and it is especially suitable for projects with tight schedules.

[0061] 2. Good soil protection and water-stopping effect between piles In this scheme, the triaxial mixing piles serve as both water stoppers and retaining walls, ensuring the seepage stability of the foundation pit and providing better retaining effect than traditional cast-in-place piles.

[0062] 3. High stiffness and small deformation Precast concrete sheet piles have high cross-sectional stiffness, which can effectively control the deformation of the foundation pit sidewalls, making them particularly suitable for projects that require strict deformation control.

[0063] 4. Excellent durability and economy Precast concrete sheet piles have strong corrosion resistance, long service life, and relatively low cost.

[0064] 5. Highly adaptable and applicable to a wide range of scenarios. Precast concrete sheet piles are suitable for shallow to medium-depth foundation pits (such as 5-10 meters). When used in conjunction with support structures, they can be effective in deeper foundation pits, especially in soft soil or areas requiring rapid construction.

[0065] Example 3: The high-pressure jet grouting piles and mixing piles used in Examples 1 and 2 are existing technologies and will not be described in detail. Examples 1 and 2 are for better demonstrating the technical improvements of Example 3. Example 3 is preferably illustrated using mixing piles as an example.

[0066] Refer to the attached diagram. Figures 1-4 , The enclosure system also includes: main support component 2, secondary support component 3, connector 4, flexible barrier 5, and drive component 6.

[0067] The main support member 2 is located in the middle of the pit. Multiple secondary support members 3 are evenly distributed along the edges of the pit. A connecting member 4 is located between the main support member 2 and the secondary support members 3. In this embodiment, both the secondary support member 3 and the main support member 2 are rods, inserted into the pit to fix their positions. The connecting member 4 is also a rod, placed obliquely between the main support member 2 and the secondary support member 3, making the secondary support member 3 more stable. The connecting member 4 is fixed to both the main support member 2 and the secondary support member 3. A flexible stop member 5 connects any two secondary support members 3 and has a stop surface that mates with the inner wall of the pit. Multiple flexible stop members 5 are provided, thus supporting the inner wall of the pit. Combined with the connecting member 4 and the secondary support members 3, the flexible stop members 5 provide more stable support to the inner wall of the pit. The flexible retaining member 5 has a water storage chamber. The driving member 6 is used to inject and extract water into the water storage chamber, causing the flexible retaining member 5 to expand until its surface is in contact with the inner wall of the pit. This allows the outer wall of the flexible retaining member 5 to deform through expansion, ensuring complete contact with the inner wall of the pit and better preventing partial collapse of the pit's inner wall. Common support methods involve using slabs erected against the inner wall of the pit. However, the inner wall of the pit is not a smooth surface, so the slabs cannot completely contact the inner wall. When the inner wall partially collapses, the stress on the slabs increases, potentially leading to slab collapse. Furthermore, after the slabs are removed, the collapsed sand between the inner wall and the slabs can hinder construction progress when preparing to resume construction. This application utilizes the flexible retaining member 5 to completely contact the inner wall of the pit, preventing partial collapse and improving the support and enclosure effect of the pit.

[0068] Refer to the attached diagram. Figures 4-6In some embodiments, the secondary support 3 includes a support rod 31 and a slot 321 disposed on the support rod 31. The flexible stop 5 includes a flexible body 51 having a water storage chamber and a pair of insert rods 52 fixedly disposed on both sides of the flexible body 51; the insert rods 52 are inserted into the slots 321. Specifically, the secondary support 3 also includes a clamp 32, which is fixed to the support rod 31, and the slots 321 are disposed on the clamp 32, with the center line of the slots 321 being separate from and parallel to the center line of the support rod 31. Thus, after the insert rod 52 is inserted into the slot 321, the insert rod 52 is located at the edge of the support rod 31. In addition, at least two clamps 32 are provided on each support rod 31, and the insert rod 52 is inserted into the slots 321 of the two clamps 32. Each clamp 32 is provided with two slots 321, so that multiple insert rods 52 can be fixed between multiple secondary support 3 by being inserted into the slots 321, thereby the multiple flexible bodies 51 forming an area that abuts against the inner wall of the pit. The insertion of the insert rod 52 into the slot 321 facilitates the installation and disassembly of the flexible body 51, thereby increasing the speed of foundation pit support and retaining structure construction, as well as the switching speed between foundation pit construction and the removal of foundation pit support and retaining structure. The use of the clamp 32 on the bearing rod 31 to form the slot 321 further reduces costs.

[0069] Refer to the attached diagram. Figure 7 In the specific design, both the slot 321 and the insert 52 have polygonal cross-sections, preferably regular polygons, and more preferably squares. The size of the insert 52 is smaller than that of the slot 321, and the circumscribed circle diameter of the insert 52 is larger than the inscribed circle diameter of the slot 321. Therefore, the insert 52 can be inserted into the slot 321 without rotating within it, and a gap exists between the insert 52 and the slot 321 after insertion. The insert 52 also has a groove 322 that communicates with the slot 321. Alternatively, the insert 52 and part of the flexible body 51 are located in the slot 321, with the flexible body 51 partially located in the groove 322. When the insert 52 and part of the flexible body 51 are in the slot 321, the flexible body 51 is partially wrapped around the insert 52. Therefore, by wrapping the flexible body 51 around the insert rod 52, the size of the insert rod 52 can be increased to fill the gap between the insert rod 52 and the slot 321, while the insert rod 52 can still be inserted into the slot 321. This achieves the goal of increasing or decreasing the length of the flexible body 51 at a relatively low cost. When there are errors in the installation positions of multiple secondary support members 3, the flexible body 51 can be wrapped around the insert rod 52 to ensure that the insert rod 52 is still inserted into the slot 321 and the flexible body 51 remains between the two secondary support members 3. This better ensures the support and enclosure of the pit inner wall by the flexible body 51.

[0070] Refer to the attached diagram. Figures 1-3 In some embodiments, to further increase the stability of the main support member 2, the foundation pit retaining system also includes connecting ropes 7. Multiple connecting ropes 7 are provided, and these ropes 7 are tautly positioned between the main support member 2 and the mixing pile 1. That is, one end of each connecting rope 7 is fixed to the mixing pile 1, and the other end is fixed to the main support member 2, thereby using the connecting ropes 7 to tighten the main support member 2 and further secure it. This allows the main support member 2 to better utilize the connecting member 4 to provide support for the secondary support member 3.

[0071] In a specific configuration, the connecting rope 7 is fixed to the upper end face of the mixing pile 1 using an expansion bolt. Alternatively, the winch can be fixed to the mixing pile 1, and then the connecting rope 7 can be fixed to the output part of the winch.

[0072] In the specific design, the connecting rope 7 is directly tied and fixed to the main support component 2.

[0073] In some embodiments, to facilitate the assembly and disassembly of the main support member 2 and the secondary support member 3, a connector 4 is used to hinge them together.

[0074] In some specific designs, the connector 4 can be directly hinged between the main support 2 and the secondary support 3 using a hinge connection.

[0075] Refer to the attached diagram. Figures 8-9 In other specific designs, the connector 4 includes a connecting rod 41, a fixed plate 42 fixedly disposed at both ends of the connecting rod 41, and a fixing block 43 with a slot 431. The shape of the slot 431 matches the fixed plate 42, and the fixed plate 42 slides against the inner wall of the slot 431. Two fixing blocks 43 are provided, one of which is connected to the main support member 2, and the other is connected to the secondary support member 3. Thus, the connector 4 is hinged between the main support member 2 and the secondary support member 3. The hinged connection method, using the cooperation of the fixed plate 42 and the slot 431, better improves the load limit of the connector 4 and avoids the risk of breakage or other damage caused by the large force of traditional hinge or shaft connections during use.

[0076] Refer to the attached diagram. Figures 9-10The fixed plate 42 has protrusions 44 at both ends, which are rods protruding outwards from the fixed plate 42. The fixed block 43 has limiting holes 432, and the protrusions 44 are located within these holes, with a movable gap between the outer wall of the protrusions 44 and the inner wall of the limiting holes 432. This movable gap is designed to prevent the limiting holes 432 from completely disengaging from the fixed plate 42 and the slot 431. Therefore, in actual use, the fixed plate 42 can be easily installed into the slot 431. Specifically, the slot 431 is a semi-circular groove, and the fixed plate 42 is directly inserted into it for easy installation. Additionally, the fixed plate 42 has through holes into which the protrusions 44 are inserted. This better ensures the stable support of the connecting member 4 for the secondary support member 3 while reducing installation difficulty.

[0077] More specifically, multiple rollers or balls are provided on the outer wall of the fixed plate 42 or the inner wall of the slot 431 to increase the smoothness of the sliding fit between the fixed plate 42 and the slot 431.

[0078] Refer to the attached diagram. Figure 7 , Figure 11 In some embodiments, a tapered rod 33 and a foot pedal 34 are provided at the lower part of the secondary support member 3. The tapered rod 33 is located below the foot pedal 34 and is used to insert into the bottom of the pit, increasing the stability of the secondary support member 3. The foot pedal 34 is used to apply a downward force to the secondary support member 3 using the weight of the operator, making it easier for the tapered rod 33 on the secondary support member 3 to be inserted into the bottom of the pit. In addition, the foot pedal 34 is located on the side of the secondary support member 3. When the tapered rod 33 is inserted into the bottom of the pit, the foot pedal 34 contacts the bottom of the pit, and the foot pedal 34 is located on the side of the secondary support member 3 closer to the main support member 2, which helps to prevent the secondary support member 3 from tipping over. Specifically, both the tapered rod 33 and the foot pedal 34 are fixed to the bearing rod 31.

[0079] Refer to the attached diagram. Figure 11 In some embodiments, the secondary support member 3 further includes a connecting block 35, with mounting grooves 351 formed at its upper and lower ends. A fixing block 43 is fixedly connected to the connecting block 35, which can be secured with bolts. A bearing rod 31 is inserted into the mounting groove 351. Each secondary support member 3 has two bearing rods 31, one inserted into the mounting groove 351 at the upper end of the connecting block 35, and the other inserted into the mounting groove 351 at the lower end of the connecting block 35, thus facilitating the installation of the bearing rods 31. This makes the components easier to transport and assemble during the construction of the support structure. Furthermore, the fixing block 43 and the connecting block 35 can also be integrally formed.

[0080] A groove is formed in the tapered rod 33, which is then embedded into the support rod 31. The pedal 34 can be fixed to either the support rod 31 or the tapered rod 33. Threaded holes are formed on both the tapered rod 33 and the connecting block 35. Bolts are screwed into these threaded holes, and the bolts tighten against the support rod 31, thus fixing the support rod 31 to the connecting pipe and to the tapered rod 33.

[0081] Refer to the attached diagram. Figure 12 In some embodiments, the flexible stop 5 further includes a rigid space frame 8. Multiple rigid space frames 8 are provided and fixed to the flexible body 51. Gaps exist between the multiple rigid space frames 8, allowing them to rotate relative to each other. The rigid space frames 8 are located on the side of the flexible body 51 facing away from the inner wall of the pit. When the flexible body 51 is installed onto the auxiliary support 3, the rigid space frame 8 contacts the bottom surface of the pit. The rigid space frame 8 is designed to ensure that the flexible body 51 expands uniformly when it expands, preventing the lower part of the flexible body 51 from expanding more than the upper part under gravity. Therefore, the flexible body 51 can make uniform contact with the inner wall of the pit.

[0082] Refer to the attached diagram. Figure 13 In some embodiments, multiple insert rods 52 are disposed between the two sides of the flexible body 51, and the insert rods 52 are located on the outer wall of the flexible body 51. Multiple support rods 31 are disposed along the contour trajectory of the foundation pit, and multiple insert rods 52 are respectively inserted into the slots 321 of the multiple support rods 31. A pair of insert rods 52 at both ends of the flexible body 51 are fixedly connected so that the flexible body 51 forms an annular closed wall area. The annular closed wall area allows the flexible body 51 to completely fit against the inner wall of the foundation pit, and also serves as a waterproofing function, or prevents soil from the inner wall of the foundation pit from seeping into the gap between the support rods 31 and the flexible body 51, thus better supporting and protecting the foundation pit. The lower end face of the insert rod 52 is provided with a cone, which can be a conical rod. Part of the insert rod 52 is inserted into the slot 321, and part of the insert rod 52 is inserted into the bottom surface of the foundation pit through the cone, which better maintains the trajectory arrangement of the flexible body 51 and better fits the closed wall area against the inner wall of the foundation pit.

[0083] Refer to the attached diagram. Figure 14Specifically, the lower part of the flexible body 51 is provided with an elastic extension 53; the extension 53 is connected to the outer wall of the flexible body 51; the extension 53 has an elastic chamber, and the driving member 6 is also used to inject water into the elastic chamber; the outer wall of the extension 53 is provided with multiple protruding cones for insertion into the bottom surface of the pit. The driving member 6 injects water into the elastic chamber, causing the extension 53 to expand, thereby allowing the protruding cones on the extension 53 to insert into the bottom surface of the pit and limit or fix the position of the extension 53. The extension 53 can limit and fix the lower part of the flexible body 51, thus better preventing the flexible body 51 from moving inward. In addition, after the elastic chamber is filled with water, the weight of the extension 53 itself can help to fix its position. Specifically, the extension 53 is made of elastic rubber material.

[0084] In addition, an interface is provided at the lower end of the flexible body 51, and the extension body 53 is directly connected to the interface to connect the water storage chamber and the elastic chamber, or a hose is provided at the interface to connect the water storage chamber and the elastic chamber through the hose.

[0085] Refer to the attached diagram. Figures 1-3 In some embodiments, the driving component 6 includes: a water pump 61, a water storage bag 62, a first connecting pipe 63 connecting the water pump 61 and the water storage bag 62, and a second connecting pipe 64 connecting the water storage bag 62 and the water storage chamber. The water storage bag 62 has an annular shape. The main support component 2 includes: a fixed rod 21 and a pressure plate 22 slidably disposed on the fixed rod 21. The water storage bag 62 is sleeved on the fixed rod 21. The connecting component 4 is hinged between the pressure plate 22 and the secondary support component 3, that is, one fixed block 43 is fixed to the connecting block 35, and the other fixed block 43 is fixed to the pressure plate 22. Therefore, since the bearing rod 31 is inserted into the bottom surface of the pit, the pressure plate 22 moves downward, which can subject the bearing rod 31 to an external force moving towards the inner wall of the pit, allowing the bearing rod 31 to press against the inner wall of the pit, and allowing the flexible body 51 to get closer to or press against the inner wall of the pit. A water storage bag 62 is positioned above the pressure plate 22. The water storage bag 62 is connected to the second connecting pipe 64 via a pressure relief valve. This allows the water storage bag 62 to fill with water before it is added to the injection chamber, giving it a certain weight. This weight exerts a downward force on the pressure plate 22, which in turn exerts an external force on the bearing rod 31 near the inner wall of the pit through the connector 4. This achieves the simultaneous injection of water into the flexible body 51 and the application of an external force to the inner wall of the pit onto the bearing rod 31. The overall structure is simpler, and installation is more convenient. The second connecting pipe 64 also connects the water storage chamber and the elastic chamber, allowing for simultaneous injection of water into the flexible body 51 and the extension body 53. Both the first connecting pipe 63 and the second connecting pipe 64 are equipped with quick-release connectors for easy installation and disassembly.

[0086] Refer to the attached diagram. Figures 3-4 , Figure 15 In other embodiments, a fixing plate 9 is provided at the top of the fixing rod 21. The fixing plate 9 has a groove 91 in the middle and multiple retaining grooves 92 on its edge. Each retaining groove 92 contains a retaining chamber 93. The end of the connecting rope 7 connected to the main support member 2 has a connecting knot, which is a knot protruding from the connecting rope 7. The connecting rope 7 is located in the retaining groove 92, and the connecting knot is located in the retaining chamber 93, thus enabling quick connection between the connecting rope 7 and the fixing rod 21, facilitating installation and disassembly. In another embodiment, a canopy is provided at the top of the fixing rod 21, resting on top of the fixing rod 21. Alternatively, a threaded hole is opened on the canopy, and a screw is screwed into the threaded hole. The canopy rests on top of the fixing rod 21, and the screw is recessed into the groove 91, achieving positioning of the canopy. Connecting ropes 7 are also provided between the fixing plates 9 on any two fixing rods 21 to connect the two fixing rods 21.

[0087] Refer to the attached diagram. Figures 1-15 The implementation principle of a foundation pit support system for foundation pit construction according to an embodiment of this application is as follows: Install the pressure plate 22 on the fixing rod 21, put the water storage bag 62 onto the fixing rod 21, and then insert the fixing rod 21 into the bottom of the middle of the pit.

[0088] Insert the bearing rod 31 into the mounting groove 351 of the connecting block 35, embed the tapered rod 33 into the bearing rod 31, install the clamp 32 onto the bearing rod 31, and then insert the bearing rod into the bottom surface of the edge of the pit.

[0089] Insert the insert rod 52 on the flexible body 51 into the slot 321 of the clamp 32, so that the flexible body 51 is located between two adjacent bearing rods 31.

[0090] The fixing plate 42 is embedded into the slot 431 of the fixing block 43, and the protrusion is positioned in the limiting hole 432. Then, one of the fixing blocks 43 is fixed together with the pressure plate 22, and the other fixing block 43 is fixed together with the connecting block 35.

[0091] Connect the extension body 53 to the flexible body 51.

[0092] Water is injected into the water storage bag 62 using the water pump 61 and the first connecting pipe 63. The weight of the water storage bag 62 increases, which applies a downward external force to the pressure plate 22. The pressure plate 22, through the connector 4, makes the bearing rod 31 press against the inner wall of the pit.

[0093] Water in the water storage bag 62 is injected into the flexible body 51 and the elastic body through the pressure relief valve and the second connecting pipe 64. The flexible body 51 expands and completely fits the inner wall of the pit. The elastic body expands and the cone on the elastic body is embedded into the bottom of the pit. The elastic body blocks the lower part of the flexible body 51 to provide support to prevent the flexible body 51 from deflecting.

[0094] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A foundation pit support system for foundation pit construction, comprising: Multiple mixing piles and precast sheet piles installed on the multiple mixing piles; Multiple mixing piles are connected end to end to form a waterproof construction area; The foundation pit is located in the waterproofing construction area; Or multiple high-pressure jet grouting piles and precast concrete sheet piles set on the high-pressure jet grouting piles; multiple high-pressure jet grouting piles and precast concrete sheet piles are connected end to end to form the waterproof construction area, and the foundation pit is located in the waterproof construction area; Its features are: The enclosure system also includes: The main support component is located in the middle of the foundation pit; Multiple secondary support components are provided and evenly distributed along the edge of the foundation pit; A connector is disposed between the main support member and the secondary support member; A flexible baffle is connected between any two secondary support members and has a baffle surface that mates with the inner wall of the pit; the flexible baffle has a water storage chamber. A drive unit is used to inject and extract water into the water storage chamber so that the flexible baffle expands until the baffle surface fits against the inner wall of the pit.

2. The foundation pit support system for foundation pit construction according to claim 1, characterized in that: The secondary support includes: a support rod and a slot disposed on the support rod; The flexible stop includes: a flexible body having the water storage chamber and a pair of insert rods fixedly disposed on both sides of the flexible body; the insert rods are inserted into the slot.

3. A foundation pit support system for foundation pit construction according to claim 2, characterized in that: Both the slot and the insert have polygonal cross-sections; the insert is smaller than the slot, and the circumcircle diameter of the insert is larger than the incircle diameter of the slot. The insertion rod is also provided with a groove, which communicates with the slot; The insert or the insert and part of the flexible body are located in the slot, and the flexible body part is located in the groove; When the insert and part of the flexible body are located in the slot, the flexible body portion is wrapped around the insert.

4. The foundation pit support system for foundation pit construction according to claim 1, characterized in that: The connector includes: a connecting rod, a fixing plate fixedly disposed at both ends of the connecting rod, and a fixing block having a slot, wherein the shape of the slot matches the fixing plate; The fixed plate slides in conjunction with the inner wall of the slot; Two fixing blocks are provided, one of which is connected to the main support member, and the other is connected to the auxiliary support member.

5. A foundation pit support system for foundation pit construction according to claim 4, characterized in that: The fixed disk has protrusions at both ends; The fixing block is provided with a limiting hole, the protrusion is located in the limiting hole, and there is an movable gap between the outer wall of the protrusion and the inner wall of the limiting hole.

6. A foundation pit retaining system for foundation pit construction according to claim 4, characterized in that: Multiple rollers or balls are provided on the outer wall of the fixed plate or the inner wall of the slot.

7. A foundation pit support system for foundation pit construction according to claim 2 or 3, characterized in that: A plurality of insert rods are disposed between the two sides of the flexible body, and the insert rods are located on the outer wall of the flexible body; The plurality of bearing rods are arranged along the contour trajectory of the foundation pit; the plurality of insert rods are respectively inserted into the slots of the plurality of bearing rods; The flexible body is fixedly connected to a set of inserts at both ends so that the flexible body forms a ring-shaped closed wall area.

8. A foundation pit retaining system for foundation pit construction according to claim 2 or 3, characterized in that: The lower part of the flexible body is provided with an elastic extension; the extension is connected to the outer wall of the flexible body. The extension has an elastic chamber, and the drive is also used to inject water into the elastic chamber; The outer wall of the extension is provided with multiple protruding cones for insertion into the bottom surface of the foundation pit.

9. A foundation pit retaining system for foundation pit construction according to claim 8, characterized in that: The driving component includes: a water pump, a water storage bag, a first connecting pipe connecting the water pump to the water storage bag, and a second connecting pipe connecting the water storage bag to the water storage chamber; The main support component includes: a fixed rod and a pressure plate slidably disposed on the fixed rod; The connector is hinged between the pressure plate and the secondary support; the water storage bag is positioned above the pressure plate; the water storage bag is connected to the second connecting pipe via a pressure relief valve.

10. A foundation pit retaining system for foundation pit construction according to claim 8, characterized in that: The foundation pit retaining system also includes: connecting ropes; multiple connecting ropes are provided, and the multiple connecting ropes are tensioned between the main support and the mixing pile.

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