Structure for actively controlling deformation of foundation pit and construction method
By combining the retaining wall, concrete support wall, support frame and loading device, along with the recycling channel and water-stop ring, the problem of poor deformation control of the pit bottom and pit wall was solved, the stability of the pit and the safety of the underground structure were guaranteed, and the cost was reduced.
Patent Information
- Application Number
- CN202511880709.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-13
- Publication Date
- 2026-02-24
AI Technical Summary
Existing structures for actively controlling the deformation of foundation pits have very limited effectiveness in controlling the deformation at and below the bottom of the pit.
The system employs a combined structure of retaining walls, concrete support walls, support frames, lower loading devices, and upper loading devices. Variable loads are applied using jacks, and combined with recovery channels and water-stop rings, active control of the pit bottom and walls is achieved.
It effectively controls the deformation of the pit bottom and walls, ensures the overall stability of the pit and the safety of existing underground structures, improves the reuse rate, and reduces costs.
Smart Images
Figure CN121556472A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of foundation pit engineering technology, and in particular to a structure and construction method for actively controlling foundation pit deformation. Background Technology
[0002] Excavation of foundation pits can cause settlement and displacement of the surrounding strata, thereby affecting the safety of existing underground structures such as tunnels, underground pipelines, overpass pile foundations, and building pile foundations.
[0003] Existing structures for actively controlling the deformation of foundation pits only have the function of actively controlling the deformation of the pit walls, while their effect on controlling the deformation of the pit bottom and below is very limited.
[0004] The existing technical solutions mentioned above have the following drawbacks: the existing structures for actively controlling the deformation of foundation pits have very limited effect on controlling the deformation of the bottom of the foundation pit and below. Summary of the Invention
[0005] In order to actively control the deformation of the pit wall, pit bottom and below the pit bottom, this application provides a structure and construction method for actively controlling the deformation of the pit.
[0006] The primary objective of this application is to provide a structure for actively controlling the deformation of a foundation pit, employing the following technical solution: A structure for actively controlling the deformation of a foundation pit includes: The retaining wall is formed on one side of the foundation pit, with its bottom end extending below the bottom of the pit. The concrete support wall is formed below the bottom of the foundation pit, and its surface is parallel to the surface of the retaining wall. Support frame, fixed inside the foundation pit; Multiple lower loading devices are evenly distributed between the concrete support wall and the retaining wall along the extension direction of the concrete support wall; one end of each lower loading device abuts against the concrete support wall and the other end abuts against the retaining wall, and is used to apply variable loads to the lower part of the retaining wall.
[0007] By adopting the above technical solution, one end of each loading device is connected to the concrete support wall, and the other end is connected to the retaining wall, which is used to apply variable loads to the lower part of the retaining wall. In this way, the deformation of the pit bottom and below can be actively controlled. This not only ensures the overall stability of the pit and the safety of operations inside the pit, but also ensures the safety of the existing underground structures.
[0008] The present application is further configured such that: a plurality of first wall-attached columns are uniformly formed along the extension direction on the side of the concrete support wall near the retaining wall; a groove is formed on each of the first wall-attached columns; the plurality of grooves correspond one-to-one with a plurality of lower loading devices; a plurality of second wall-attached columns are uniformly formed along the extension direction on the side of the retaining wall near the concrete support wall; the plurality of second wall-attached columns abut against each other in a one-to-one correspondence with the plurality of first wall-attached columns. Each downloading device includes: There are multiple jacks arranged in multiple layers; one end of each jack presses against the inner wall of the groove, and the other end presses against the side of the second wall-mounted column closest to the first wall-mounted column.
[0009] By adopting the above technical solution, the multiple jacks of each loading device are arranged in multiple vertical layers in the vertical direction, and they cooperate with each other to apply multiple layers of variable loads to the lower part of the retaining wall in the vertical direction, which greatly improves the ability to control the deformation of the pit bottom.
[0010] This application further includes: A concrete base slab is formed on the inner bottom surface of the foundation pit; multiple recycling channels are formed on the concrete base slab; the multiple recycling channels are connected to multiple grooves in a one-to-one correspondence; Multiple water-stop rings are installed at the connection points between the recycling channels and the grooves, corresponding one-to-one with the multiple recycling channels.
[0011] By adopting the above technical solution, after multiple loading devices actively control the deformation of the pit bottom, the concrete base plate replaces the multiple loading devices to support the lower part of the retaining wall. The loading devices in the groove can be retrieved through the recovery channel, improving the reuse rate of the loading devices and reducing costs. Multiple water-stop rings are correspondingly installed at the connection between the recovery channel and the groove, preventing water from flowing into the groove and the recovery channel.
[0012] This application further includes: A cushion layer is formed on the inner bottom surface of the foundation pit; multiple recycling channels are formed on the cushion layer; the multiple recycling channels are connected to multiple grooves one by one; Multiple water-stop rings are installed at the connection points between the recycling channels and the grooves, corresponding one-to-one with the multiple recycling channels.
[0013] A concrete base slab is formed above the top surface of the subbase.
[0014] By adopting the above technical solution, after multiple loading devices actively control the deformation of the pit bottom, the cushion layer replaces the multiple loading devices to support the lower part of the retaining wall. The loading devices within the groove can be retrieved through the recovery channel, improving the reuse rate of the loading devices and reducing costs. Multiple water-stop rings are correspondingly installed at the connection points between the recovery channel and the groove, preventing water from flowing into the groove and recovery channel. A concrete base slab is formed above the top surface of the cushion layer, providing reinforced support.
[0015] This application is further configured such that: after the multiple loading devices disengage from the corresponding grooves through the corresponding recycling channels, backfill material is filled into each groove and each recycling channel; The backfill body consists of a lower backfill layer, a partition, and an upper backfill layer, arranged sequentially from bottom to top; the partition is fixed inside the recycling channel; the thickness of the upper backfill layer is 3-5cm.
[0016] By adopting the above technical solution, the lower backfill layer, serving as the foundational load-bearing layer at the defect location, can be tightly connected to the groove / recycling channel. Baffles are fixed within the recycling channel to distribute vertical loads and prevent shear failure within the backfill. The upper backfill layer provides a smooth load-bearing surface at the defect location. Micro-expansion concrete compensates for shrinkage, ensuring a dense, crack-free surface.
[0017] This application further includes: Multiple linkage loading devices are evenly distributed between the concrete support wall and the retaining wall along the extension direction of the concrete support wall; multiple linkage loading devices are alternately set with multiple lower loading devices. Each linkage loading device includes: The first support member has one end abutting against the top of the concrete support wall on the side closest to the enclosure wall; The second support member has an axis perpendicular to the axis of the first support rod, and one side abuts against the lower part of the side of the enclosure wall closest to the concrete support wall. The force-applying component has one end abutting against the end of the first support component away from the concrete support wall, and the other end abutting against the side of the second support component away from the enclosure wall.
[0018] By adopting the above technical solution, multiple linkage loading devices and multiple lower loading devices are alternately set up to play a role in linking and balancing the load at the bottom of the pit.
[0019] This application further comprises: multiple upper loading devices, evenly distributed between the support frame and the retaining wall along the extension direction of the support frame; one end of each upper loading device abuts against the support frame and the other end abuts against the retaining wall, for applying a variable load to the upper part of the retaining wall; Multiple first reinforcing plates are pre-embedded inside the contact point between the retaining wall and each lower loading device from top to bottom; multiple second reinforcing plates are pre-embedded inside the contact point between the retaining wall and each upper loading device from top to bottom; multiple third reinforcing plates are pre-embedded inside the contact point between the concrete support wall and each lower loading device from top to bottom; and multiple fourth reinforcing plates are pre-embedded inside the contact point between the support frame and each upper loading device from top to bottom.
[0020] By adopting the above technical solution, one end of each upper loading device abuts against the support frame, and the other end abuts against the retaining wall, for applying variable loads to the upper part of the retaining wall. This allows for active control of the deformation of the pit wall. Multiple first and second reinforcing plates reinforce the retaining wall, preventing damage to its load-bearing components. Multiple third reinforcing plates reinforce the concrete support wall, preventing damage to its load-bearing components. Multiple fourth reinforcing plates reinforce the support frame, preventing damage to its load-bearing components.
[0021] The second objective of this application is to provide a construction method for actively controlling the deformation of a foundation pit, employing the following technical solution: A construction method for actively controlling the deformation of a foundation pit includes the following steps: S1. Construct a retaining wall on one side of the excavation pit and below the bottom of the pit; construct a concrete support wall below the bottom of the excavation pit; fix the support frame inside the excavation pit; S2. Make one end of each lower loading device abut against the top of one side of the concrete support wall and the other end abut against the lower part of one side of the retaining wall; and make one end of each upper loading device abut against one side of the support frame and the other end abut against the upper part of one side of the retaining wall. S3. Form a concrete base slab or cushion layer on the inner bottom surface of the foundation pit.
[0022] By adopting the above technical solutions, the deformation of the pit walls, bottom, and below the bottom can be actively controlled. This not only ensures the overall stability of the pit and the safety of operations inside, but also guarantees the safety of existing underground structures.
[0023] This application is further configured such that: in step S1, when forming the concrete support wall, multiple grooves are reserved in the concrete support wall; in step S3, when forming the concrete base plate or cushion layer, multiple recycling channels are reserved in the concrete base plate or cushion layer; the multiple recycling channels are connected to the multiple grooves one by one. It also includes the following steps: S4. Allow the multiple loading devices to disengage from their respective grooves through their corresponding recovery channels; S5. Fill each groove and each recycling channel with backfill material.
[0024] This application further specifies that step S5 includes: S51. Fill each groove and each recycling channel with micro-expansion concrete to form the lower backfill layer; S52. Install a baffle plate at the top of each recycling channel so that the bottom surface of the baffle plate contacts the top surface of the lower backfill layer; S53. Fill each recycling channel with micro-expansion concrete to form an upper backfill layer with a thickness of 3-5 cm above the top surface of the partition.
[0025] In summary, the beneficial technical effects of this application are as follows: 1. Each lower loading device has one end abutting against the concrete support wall and the other end abutting against the retaining wall, applying variable loads to the lower part of the retaining wall. This allows for proactive control of deformation at and below the pit bottom. Similarly, each upper loading device has one end abutting against the support frame and the other end abutting against the retaining wall, applying variable loads to the upper part of the retaining wall. This also allows for proactive control of pit wall deformation. This not only ensures the overall stability of the pit and the safety of operations within it, but also guarantees the safety of existing underground structures.
[0026] 2. The multiple jacks of each loading device are arranged in multiple vertical layers, working together to apply multiple layers of variable loads to the lower part of the retaining wall in the vertical direction, which greatly improves the ability to control the deformation of the pit bottom.
[0027] 3. After multiple loading devices complete the task of actively controlling the deformation of the pit bottom, the concrete base plate replaces the multiple loading devices to support the lower part of the retaining wall. The loading devices in the groove can be retrieved through the recovery channel, improving the reuse rate of the loading devices and reducing costs. Multiple water-stop rings are correspondingly installed at the connection between the recovery channel and the groove, preventing water from flowing into the groove and the recovery channel.
[0028] 4. After the multiple loading devices detach from their respective grooves through the corresponding recovery channels, backfill material is filled into each groove and each recovery channel. The backfill material consists of a lower backfill layer, a baffle plate, and an upper backfill layer, arranged sequentially from bottom to top. The lower backfill layer serves as the basic load-bearing layer at the defect location, ensuring a tight connection with the groove / recovery channel. The baffle plate is fixed within the recovery channel to distribute vertical loads and prevent shear failure within the backfill material. The upper backfill layer provides a smooth load-bearing surface at the defect location. Micro-expansion concrete compensates for shrinkage, ensuring a dense, crack-free surface. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of an embodiment of a structure for actively controlling the deformation of a foundation pit; Figure 2 yes Figure 1 The structure shown is a cross-sectional view along AA for actively controlling the deformation of the foundation pit. Figure 3 yes Figure 2 A magnified view of a portion of region B in the middle; Figure 4 yes Figure 2 A magnified view of a portion of region C in the middle; Figure 5 This is a schematic diagram of another embodiment of a structure for actively controlling the deformation of a foundation pit; Figure 6 yes Figure 5 The structure shown is a cross-sectional view along DD for actively controlling the deformation of the foundation pit; Figure 7 yes Figure 6 A magnified view of a portion of region E in the middle; Figure 8 This is a schematic diagram of the combined structure of the upper isolation cylinder and the water-stop ring; Figure 9 This is a schematic diagram of the structure after backfill material has been filled into the grooves and recycling channels; Figure 10 yes Figure 9 A magnified view of a portion of region F in the middle; Figure 11 This is a schematic diagram of another embodiment of a structure for actively controlling the deformation of a foundation pit; Figure 12 yes Figure 11 The structure shown is a cross-sectional view along GG of the structure for actively controlling the deformation of the foundation pit. Figure 13 yes Figure 12 A magnified view of a portion of region H in the middle; Figure 14 This is a schematic diagram of another embodiment of a structure for actively controlling the deformation of a foundation pit; Figure 15 yes Figure 14 The diagram shows a combined structure of a linkage loading device, a concrete support wall, and a retaining wall in a structure for actively controlling the deformation of an excavation pit. Figure 16 This is a structural schematic diagram of each linkage loading device; Figure 17 This is a schematic diagram of another embodiment of a structure for actively controlling the deformation of the foundation pit; Figure 18 yes Figure 17 The structure shown is a cross-sectional view along II for actively controlling the deformation of the foundation pit.
[0030] Reference numerals: 110, Enclosure wall; 111, Second attached column; 1111, First reinforcing plate; 1112, Second reinforcing plate; 120, Concrete support wall; 121, First attached column; 1211, Groove; 1212, Third reinforcing plate; 122, Lower isolation cylinder; 130, Support frame; 131, Insert rod; 132, Fourth reinforcing plate; 140, Lower loading device; 141, Jack; 150, Upper loading device; 160, Concrete 161. Soil base slab; 162. Recycling channel; 163. Upper isolation cylinder; 164. Water-stop ring; 170. Backfill body; 171. Lower backfill layer; 172. Partition plate; 173. Upper backfill layer; 180. Subbase layer; 190. Linkage loading device; 191. First support member; 192. Second support member; 193. Force application member; 200. Passive zone soil; 210. Excavation pit; 220. Insertion hole; 300. Active zone soil; 400. Existing underground structure. Detailed Implementation
[0031] It should be noted that existing underground structures can include tunnels, underground pipelines, overpass pile foundations, building pile foundations, and other objects to be protected.
[0032] The following is in conjunction with the appendix Figure 1-18 This application will be described in further detail.
[0033] Reference Figure 1 and Figure 2This application discloses a structure for actively controlling the deformation of a foundation pit, including a retaining wall 110, a concrete support wall 120, a support frame 130, multiple lower loading devices 140, and multiple upper loading devices 150. The retaining wall 110 is formed on one side of the foundation pit 210, with its bottom extending below the bottom of the foundation pit 210. It should be noted that the soil on the side of the retaining wall 110 away from the foundation pit 210 is the active zone soil 300, and the soil on the side of the retaining wall 110 close to the foundation pit 210 is the passive zone soil 200. The foundation pit 210 is formed on top of the passive zone soil 200. Existing underground structures 400, such as tunnels, underground pipelines, overpass pile foundations, and building pile foundations, are buried within the active zone soil 300. The concrete support wall 120 is formed below the bottom of the foundation pit 210, and its surface is parallel to the surface of the retaining wall 110. That is, a concrete support wall 120 is formed within the passive zone soil 200. A support frame 130 is fixed within the foundation pit 210. Multiple lower loading devices 140 are evenly distributed between the concrete support wall 120 and the retaining wall 110 along the extension direction of the concrete support wall 120. One end of each lower loading device 140 abuts against the concrete support wall 120, and the other end abuts against the retaining wall 110, for applying a variable load to the lower part of the retaining wall 110. In this way, the deformation of the bottom of the foundation pit 210 and below can be actively controlled. Multiple upper loading devices 150 are evenly distributed between the support frame 130 and the retaining wall 110 along the extension direction of the support frame 130. One end of each upper loading device 150 abuts against the support frame 130, and the other end abuts against the retaining wall 110, for applying a variable load to the upper part of the retaining wall 110. In this way, the deformation of the pit wall of the foundation pit 210 can be actively controlled. This not only ensured the overall stability of the foundation pit 210 and the safety of operations inside the pit, but also ensured the safety of the existing underground structure 400.
[0034] Preferably, the enclosure wall 110 is provided with a plurality of first wall panels along its extension direction. The adjacent sides of any two adjacent first wall panels abut against each other. The orthographic projection of each first wall panel from top to bottom is "L"-shaped or "T"-shaped.
[0035] Preferably, the concrete support wall 120 is provided with a plurality of second wall panels along its extension direction. The adjacent sides of every two adjacent second wall panels abut against each other. The orthographic projection of each second wall panel from top to bottom is "L"-shaped or "T"-shaped.
[0036] Preferably, such as Figure 2 As shown, multiple insertion holes 220 are formed within the passive zone soil 200. Multiple insertion rods 131 are provided along the extension direction of the support frame 130. The multiple insertion rods 131 are inserted into the insertion holes 220 one-to-one, to fix the support frame 130 within the foundation pit 210. The support frame 130 can be a steel frame, a wooden frame, or a precast concrete frame, etc.
[0037] Preferably, such as Figure 3 As shown, each upper loading device 150 is a jack.
[0038] In one embodiment, reference is made to Figure 1 , Figure 2 and Figure 4 Each first wall panel and each second wall panel, when projected downwards, forms a "T" shape. Multiple first wall-mounted columns 121 are uniformly formed along the extending direction on the side of the concrete support wall 120 near the retaining wall 110. Each first wall-mounted column 121 has a groove 1211. The multiple grooves 1211 correspond one-to-one with multiple lower loading devices 140. Each groove 1211 is used for the installation of its corresponding lower loading device 140. Multiple second wall-mounted columns 111 are uniformly formed along the extending direction on the side of the retaining wall 110 near the concrete support wall 120. The multiple second wall-mounted columns 111 abut against each other, corresponding one-to-one with the multiple first wall-mounted columns 121. Each lower loading device 140 includes multiple jacks 141. The multiple jacks 141 are arranged in multiple layers. One end of each jack 141 presses against the inner wall of the groove 1211, and the other end presses against the side of the second wall-mounted column 111 near the first wall-mounted column 121. Because the multiple jacks 141 of each lower loading device 140 are arranged vertically in multiple layers, they cooperate with each other to apply multiple layers of variable loads to the lower part of the retaining wall 110 in the vertical direction, greatly improving the ability to control the deformation of the pit bottom. It should be noted that each lower loading device 140 includes two, three, four, five, six or more jacks 141, arranged in two, three, four or more layers.
[0039] In another embodiment, the top-down orthographic projection of each first wall panel and each second wall panel forms a "T" shape. Multiple first wall-attached columns 121 are uniformly formed along the extension direction on the side of the concrete support wall 120 near the retaining wall 110. Each first wall-attached column 121 has a groove 1211. The multiple grooves 1211 correspond one-to-one with multiple lower loading devices 140. The multiple grooves 1211 are respectively used for the installation of the corresponding lower loading device 140. Multiple second wall-attached columns 111 are uniformly formed along the extension direction on the side of the retaining wall 110 near the concrete support wall 120. The multiple second wall-attached columns 111 abut against each other in a one-to-one correspondence with the multiple first wall-attached columns 121. Each lower loading device 140 is a hydraulic splitting rod, vertically installed in the corresponding groove 1211, applying multiple layers of variable loads to the lower part of the retaining wall 110 in the vertical direction, greatly improving the ability to control the deformation of the pit bottom.
[0040] It should be noted that the concrete support wall 120 is a cast-in-place concrete wall, and its formation process is as follows: First, a reinforcing cage is fabricated on site, and then concrete is poured on the reinforcing cage to form the concrete support wall 120. To ensure that each first attached column 121 has a groove 1211, multiple lower isolation cylinders 122 are installed on the reinforcing cage before the concrete is poured. After the concrete is poured, the interior of each lower isolation cylinder 122 is used as a groove 1211 for installing the lower loading device 140. The lower isolation cylinder 122 can be a steel cylinder, an iron cylinder, or a wooden cylinder.
[0041] Of course, the 120mm concrete support wall can also be a precast concrete wall, which saves on-site construction time, improves construction efficiency, and reduces construction costs.
[0042] Reference Figure 5 , Figure 6 , Figure 7 and Figure 8 In one embodiment, the structure for actively controlling the deformation of the foundation pit further includes a concrete base slab 160 and multiple water-stop rings 163. The concrete base slab 160 is formed on the inner bottom surface of the foundation pit 210. Multiple recovery channels 161 are formed on the concrete base slab 160. The multiple recovery channels 161 are connected to multiple grooves 1211 in a one-to-one correspondence. After the multiple loading devices 140 complete the task of actively controlling the deformation of the pit bottom, the concrete base slab 160 replaces the multiple loading devices 140 in supporting the lower part of the retaining wall 110. The loading devices 140 in the grooves 1211 can be recovered through the recovery channels 161, improving the reuse rate of the loading devices 140 and reducing costs. Multiple water-stop rings 163 are arranged at the communication points between the recovery channels 161 and the grooves 1211, corresponding to the multiple recovery channels 161, to prevent water from flowing into the grooves 1211 and the recovery channels 161.
[0043] It should be noted that the concrete base slab 160 is a cast-in-place concrete slab, and its formation process is as follows: First, the base slab reinforcement is tied on site, and then concrete is poured on the base slab reinforcement to form the concrete base slab 160. To ensure that multiple recovery channels 161 are formed on the concrete base slab 160, multiple upper isolation cylinders 162 are installed on the base slab reinforcement before the concrete is poured, and multiple water-stop rings 163 are fixed to the bottom end of the upper isolation cylinders 162 one-to-one. The connection can be made by welding or bolting. After the concrete is poured, the interior of each upper isolation cylinder 162 is used as a recovery channel 161. The upper isolation cylinder 162 can be a steel cylinder, iron cylinder, or wooden cylinder. After the cast-in-place concrete slab reaches the required strength, the lower loading device 140 is then recovered.
[0044] Of course, the 160mm concrete base slab can also be a precast concrete slab, which saves on-site construction time, improves construction efficiency, and reduces construction costs.
[0045] Reference Figure 6 , Figure 9 and Figure 10 After the multiple loading devices 140 disengage from their respective grooves 1211 through the corresponding recycling channels 161, they fill each groove 1211 and each recycling channel 161 with backfill material 170 to compensate for the local strength deficiencies in the concrete support wall 120 and the concrete base slab 160, thereby increasing the local load-bearing capacity. The backfill material 170 is provided with a lower backfill layer 171, a partition 172, and an upper backfill layer 173 sequentially from bottom to top. The partition 172 is fixed within the recycling channel 161; that is, the edge of the partition 172 is fixedly connected to the inner wall of the upper partition cylinder 162, further enhancing the strength of the backfill material 170. The lower backfill layer 171 is formed by the curing of micro-expansion concrete and serves as the basic load-bearing layer at the defect location, ensuring a tight connection with the groove 1211 / recycling channel 161. The partition 172, made of steel, iron, or wood, is horizontally positioned and fixed within the recycling channel 161 to distribute vertical loads and prevent shear failure within the backfill 170. The upper backfill layer 173, 3-5 cm thick, is formed by the curing of micro-expansion concrete and is located above the partition 172, providing a smooth load-bearing surface at defects. The micro-expansion concrete compensates for shrinkage, ensuring a dense, crack-free surface.
[0046] Reference Figure 11 , Figure 12 and Figure 13 In another embodiment, the structure for actively controlling the deformation of the foundation pit further includes a cushion layer 180, multiple water-stop rings 163, and a concrete base slab 160. The cushion layer 180 is formed on the inner bottom surface of the foundation pit 210. Multiple recovery channels 161 are formed on the cushion layer 180. The multiple recovery channels 161 are connected to multiple grooves 1211 in a one-to-one correspondence. After the multiple loading devices 140 complete the task of actively controlling the deformation of the pit bottom, the cushion layer 180 replaces the multiple loading devices 140 to support the lower part of the retaining wall 110. The loading devices 140 in the grooves 1211 can be recovered through the recovery channels 161, improving the reuse rate of the loading devices 140 and reducing costs. The multiple water-stop rings 163 are arranged at the communication points between the recovery channels 161 and the grooves 1211 in a one-to-one correspondence with the multiple recovery channels 161, serving to prevent water from flowing into the grooves 1211 and the recovery channels 161. The concrete base slab 160 is formed above the top surface of the subbase 180, serving to strengthen the support.
[0047] It should be noted that the foundation layer 180 is a cast-in-place concrete foundation layer, and multiple upper isolation cylinders 162 are used to form multiple recovery channels 161 on the foundation layer 180. After the cast-in-place concrete foundation layer reaches the required strength, the lower loading device 140 in the groove 1211 is recovered through the recovery channel 161. After the multiple lower loading devices 140 are respectively detached from the corresponding groove 1211 through the corresponding recovery channel 161, backfill material 170 is filled into each groove 1211 and each recovery channel 161 to compensate for the local strength of the concrete support wall 120 and the concrete base slab 160 and improve the local load-bearing capacity. Afterwards, the concrete base slab 160 is formed by casting concrete on the top surface of the foundation layer 180.
[0048] Of course, the 180mm subbase can also be a precast concrete subbase, which saves on-site construction time, improves construction efficiency, and reduces construction costs.
[0049] Reference Figure 14 , Figure 15 and Figure 16 In one embodiment, the structure for actively controlling the deformation of the foundation pit further includes multiple linked loading devices 190. These linked loading devices 190 are evenly distributed between the concrete support wall 120 and the retaining wall 110 along the extension direction of the concrete support wall 120. The multiple linked loading devices 190 are alternately arranged with multiple lower loading devices 140, serving to balance the load at the bottom of the pit. Each linked loading device 190 includes a first support member 191, a second support member 192, and a force-applying member 193. One end of the first support member 191 abuts against the top of the side of the concrete support wall 120 near the retaining wall 110. The axis of the second support member 192 is perpendicular to the axis of the first support member, and one side abuts against the lower part of the side of the retaining wall 110 near the concrete support wall 120, thus balancing the load. One end of the force-applying member 193 abuts against the end of the first support member 191 away from the concrete support wall 120, and the other end abuts against the side of the second support member 192 away from the enclosure wall 110, thus applying a variable load. It should be noted that, as... Figure 15 As shown, the first support member 191 of each linkage loading device 190 presses against the adjacent sides of each pair of adjacent second wall panels, and the second support member 192 presses against the adjacent sides of each pair of adjacent first wall panels, ensuring uniform load distribution.
[0050] Preferably, the first support rod and the second support rod can be steel pipes, structural steel, or precast piles.
[0051] Preferably, the force-applying component 193 is a jack or other linear actuator.
[0052] Reference Figure 3 and Figure 4Multiple first reinforcing plates 1111 are embedded from top to bottom inside the abutment of the retaining wall 110 with each lower loading device 140. Multiple second reinforcing plates 1112 are embedded from top to bottom inside the abutment of the retaining wall 110 with each upper loading device 150. The multiple first reinforcing plates 1111 and the multiple second reinforcing plates 1112 serve a reinforcing function, preventing damage to the stress-bearing parts of the retaining wall 110. Multiple third reinforcing plates 1212 are embedded from top to bottom inside the abutment of the concrete support wall 120 with each lower loading device 140. The multiple third reinforcing plates 1212 serve a reinforcing function, preventing damage to the stress-bearing parts of the concrete support wall 120. Multiple fourth reinforcing plates 132 are embedded from top to bottom inside the abutment of the support frame 130 with each upper loading device 150. The multiple fourth reinforcing plates 132 serve a reinforcing function, preventing damage to the stress-bearing parts of the support frame 130.
[0053] This application also discloses a construction method for actively controlling the deformation of the foundation pit 210, which is achieved by using a structure for actively controlling the deformation of the foundation pit, including the following steps: S1. A retaining wall 110 is formed on one side of the foundation pit 210 and below the bottom of the pit, and a concrete support wall 120 is formed below the bottom of the foundation pit 210, and the support frame 130 is fixed inside the foundation pit 210.
[0054] S2. One end of each lower loading device 140 abuts against the top of one side of the concrete support wall 120, and the other end abuts against the lower part of one side of the retaining wall 110. And one end of each upper loading device 150 abuts against one side of the support frame 130, and the other end abuts against the upper part of one side of the retaining wall 110.
[0055] S3. A concrete base slab 160 or a cushion layer 180 is formed on the inner bottom surface of the foundation pit 210.
[0056] Overall, it can actively control the deformation of the pit walls, pit bottom, and below the pit bottom of the foundation pit 210. This not only ensures the overall stability of the foundation pit 210 and the safety of operations inside the pit, but also ensures the safety of the existing underground structure 400.
[0057] In one embodiment, in step S1, when forming the concrete support wall 120, multiple grooves 1211 are pre-reserved on the concrete support wall 120 using multiple lower isolation cylinders 122. In step S3, when forming the concrete base slab 160 or the cushion layer 180, multiple recycling channels 161 are pre-reserved on the concrete base slab 160 or the cushion layer 180 using upper isolation cylinders 162. The multiple recycling channels 161 are connected to the multiple grooves 1211 in a one-to-one correspondence. The construction method for actively controlling the deformation of the foundation pit 210 further includes the following steps: S4. The multiple loading devices 140 are respectively disengaged from the corresponding grooves 1211 through the corresponding recycling channels 161.
[0058] S5. Fill each groove 1211 and each recycling channel 161 with backfill material 170.
[0059] Step S5 includes: S51. Fill each groove 1211 and each recycling channel 161 with micro-expansion concrete to form the lower backfill layer 171.
[0060] S52. Install a baffle 172 at the top of each recycling channel 161, such that the bottom surface of the baffle 172 contacts the top surface of the lower backfill layer 171.
[0061] S53. Fill each recycling channel 161 with micro-expansion concrete to form an upper backfill layer 173 with a thickness of 3-5 cm above the top surface of the partition 172.
[0062] It should be noted that the lower backfill layer 171, formed by the curing of micro-expansion concrete, serves as the foundational load-bearing layer at the defect location, ensuring a tight connection with the groove 1211 / recycling channel 161. The partition 172 is horizontally positioned and fixed within the recycling channel 161, distributing vertical loads and preventing internal shear failure of the backfill 170. The upper backfill layer 173, also formed by the curing of micro-expansion concrete, is located above the partition 172, providing a smooth load-bearing surface at the defect location. The micro-expansion concrete compensates for shrinkage, ensuring a dense, crack-free surface.
[0063] Reference Figure 17 and Figure 18 This application also discloses a construction method for actively controlling the deformation of a foundation pit, comprising the following steps: T1. A retaining wall 110 is formed on one side of the foundation pit 210 and below the bottom of the pit. The support frame 130 is fixed inside the foundation pit 210. A concrete support wall 120 is formed below the bottom end of the support frame 130.
[0064] T2. One end of each lower loading device 140 abuts against the middle of one side of the concrete support wall 120, and the other end abuts against the lower part of one side of the retaining wall 110. And one end of each upper loading device 150 abuts against one side of the support frame 130, and the other end abuts against the upper part of one side of the retaining wall 110.
[0065] T3. Excavate the earthwork to the bottom of the pit and remove the concrete support wall 120 located above the bottom of the pit.
[0066] T4. A concrete base slab 160 or a cushion layer 180 is formed on the inner bottom surface of the foundation pit 210.
[0067] T5. The multiple loading devices 140 are disengaged from their respective grooves 1211 through their respective recycling channels 161.
[0068] T6. Fill each groove 1211 and each recycling channel 161 with backfill material 170.
[0069] It should be noted that after the concrete support wall 120 located above the bottom of the pit was removed, the structure was as follows: Figure 2 As shown.
[0070] The implementation principle of this embodiment is as follows: Multiple lower loading devices 140 are evenly distributed between the concrete support wall 120 and the retaining wall 110 along the extension direction of the concrete support wall 120. One end of each lower loading device 140 abuts against the concrete support wall 120, and the other end abuts against the retaining wall 110, for applying a variable load to the lower part of the retaining wall 110. In this way, the deformation of the bottom of the pit 210 and below the bottom can be actively controlled. Multiple upper loading devices 150 are evenly distributed between the support frame 130 and the retaining wall 110 along the extension direction of the support frame 130. One end of each upper loading device 150 abuts against the support frame 130, and the other end abuts against the retaining wall 110, for applying a variable load to the upper part of the retaining wall 110. In this way, the deformation of the pit wall of the pit 210 can be actively controlled. This not only ensures the overall stability of the pit 210 and the safety of operations inside the pit, but also ensures the safety of the existing underground structure 400.
[0071] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A structure for actively controlling the deformation of a foundation pit, characterized in that, include: A retaining wall (110) is formed on one side of the foundation pit (210), with its bottom end extending below the bottom of the foundation pit (210); A concrete support wall (120) is formed below the bottom of the foundation pit (210), and its surface is parallel to the surface of the retaining wall (110). A support frame (130) is fixed inside the foundation pit (210); Multiple lower loading devices (140) are evenly distributed between the concrete support wall (120) and the retaining wall (110) along the extension direction of the concrete support wall (120); one end of each lower loading device (140) abuts against the concrete support wall (120) and the other end abuts against the retaining wall (110) to apply a variable load to the lower part of the retaining wall (110).
2. The structure for actively controlling the deformation of the foundation pit according to claim 1, characterized in that, On the side of the concrete support wall (120) near the enclosure wall (110), a plurality of first wall-attached columns (121) are uniformly formed along the extending direction; each first wall-attached column (121) has a groove (1211); the plurality of grooves (1211) correspond one-to-one with the plurality of lower loading devices (140); on the side of the enclosure wall (110) near the concrete support wall (120), a plurality of second wall-attached columns (111) are uniformly formed along the extending direction; the plurality of second wall-attached columns (111) abut against each other in a one-to-one correspondence with the plurality of first wall-attached columns (121); Each of the said loading devices (140) includes: There are multiple jacks (141) arranged in multiple layers; one end of each jack (141) presses against the inner wall of the groove (1211), and the other end presses against the side of the second wall-mounted column (111) near the first wall-mounted column (121).
3. The structure for actively controlling the deformation of the foundation pit according to claim 2, characterized in that, Also includes: A concrete base slab (160) is formed on the inner bottom surface of the foundation pit (210); a plurality of recycling channels (161) are formed on the concrete base slab (160); the plurality of recycling channels (161) are connected to the plurality of grooves (1211) in a one-to-one correspondence; Multiple water-stop rings (163) are provided at the connection between the recycling channel (161) and the groove (1211), corresponding one-to-one with the multiple recycling channels (161).
4. The structure for actively controlling the deformation of the foundation pit according to claim 2, characterized in that, Also includes: A cushion layer (180) is formed on the inner bottom surface of the foundation pit (210); a plurality of recycling channels (161) are formed on the cushion layer (180); the plurality of recycling channels (161) are connected to the plurality of grooves (1211) in a one-to-one correspondence; Multiple water-stop rings (163) are provided at the communication points between the recycling channels (161) and the grooves (1211), corresponding one-to-one with the multiple recycling channels (161). A concrete base slab (160) is formed above the top surface of the cushion layer (180).
5. The structure for actively controlling the deformation of the foundation pit according to claim 3 or 4, characterized in that, After the multiple loading devices (140) are disengaged from the corresponding grooves (1211) through the corresponding recycling channels (161), backfill material (170) is filled into each groove (1211) and each recycling channel (161); The backfill body (170) is provided with a lower backfill layer (171), a partition (172) and an upper backfill layer (173) from bottom to top; the partition (172) is fixed in the recycling channel (161); the thickness of the upper backfill layer (173) is 3-5cm.
6. The structure for actively controlling the deformation of the foundation pit according to claim 1, characterized in that, Also includes: Multiple linkage loading devices (190) are evenly distributed between the concrete support wall (120) and the enclosure wall (110) along the extension direction of the concrete support wall (120). Multiple linkage loading devices (190) and multiple lower loading devices (140) are alternately arranged; Each of the aforementioned linkage loading devices (190) includes: The first support member (191) abuts against the top of the concrete support wall (120) on the side near the enclosure wall (110) at one end; The second support member (192) has an axis perpendicular to the axis of the first support rod, and one side abuts against the lower part of the side of the enclosure wall (110) near the concrete support wall (120). The force-applying member (193) has one end abutting against the end of the first support member (191) away from the concrete support wall (120), and the other end abutting against the side of the second support member (192) away from the enclosure wall (110).
7. The structure for actively controlling the deformation of the foundation pit according to claim 1, characterized in that, Also includes: Multiple upper loading devices (150) are evenly distributed between the support frame (130) and the enclosure wall (110) along the extension direction of the support frame (130); one end of each upper loading device (150) abuts against the support frame (130) and the other end abuts against the enclosure wall (110), and is used to apply a variable load to the upper part of the enclosure wall (110); Multiple first reinforcing plates (1111) are pre-embedded inside the contact points between the retaining wall (110) and each of the lower loading devices (140) from top to bottom; multiple second reinforcing plates (1112) are pre-embedded inside the contact points between the retaining wall (110) and each of the upper loading devices (150) from top to bottom; multiple third reinforcing plates (1212) are pre-embedded inside the contact points between the concrete support wall (120) and each of the lower loading devices (140) from top to bottom; and multiple fourth reinforcing plates (132) are pre-embedded inside the contact points between the support frame (130) and each of the upper loading devices (150) from top to bottom.
8. A construction method for actively controlling the deformation of a foundation pit, characterized in that, The structure for actively controlling the deformation of the foundation pit, as described in any one of claims 1 to 7, is used to achieve this, and includes the following steps: S1. The retaining wall (110) is formed on one side of the foundation pit (210) and below the bottom of the pit; the concrete support wall (120) is formed below the bottom of the foundation pit (210); the support frame (130) is fixed inside the foundation pit (210); S2. One end of each of the lower loading devices (140) abuts against the top of one side of the concrete support wall (120), and the other end abuts against the lower part of one side of the enclosure wall (110); and one end of each of the upper loading devices (150) abuts against one side of the support frame (130), and the other end abuts against the upper part of one side of the enclosure wall (110); S3. A concrete base plate (160) or a cushion layer (180) is formed on the inner bottom surface of the foundation pit (210).
9. The construction method for actively controlling the deformation of a foundation pit according to claim 8, characterized in that, In step S1, when forming the concrete support wall (120), a plurality of grooves (1211) are reserved on the concrete support wall (120); in step S3, when forming the concrete base plate (160) or the cushion layer (180), a plurality of recycling channels (161) are reserved on the concrete base plate (160) or the cushion layer (180); the plurality of recycling channels (161) are connected to the plurality of grooves (1211) in a one-to-one correspondence; It also includes the following steps: S4. The plurality of loading devices (140) are disengaged from the corresponding grooves (1211) through the corresponding recycling channels (161); S5. Fill each of the grooves (1211) and each of the recycling channels (161) with backfill material (170).
10. The construction method for actively controlling the deformation of a foundation pit according to claim 9, characterized in that, Step S5 includes: S51. Fill each of the grooves (1211) and each of the recycling channels (161) with micro-expansion concrete to form a lower backfill layer (171); S52. Install a partition (172) on the upper part of each of the recycling channels (161) such that the bottom surface of the partition (172) contacts the top surface of the lower backfill layer (171); S53. Fill each of the recycling channels (161) with the micro-expansion concrete to form an upper backfill layer (173) with a thickness of 3-5 cm above the top surface of the partition (172).