Multi-section linkage soil retaining protection device in deep foundation pit excavation

Abstract

The invention relates to the technical field of foundation pit protection, in particular to a multi-section linkage soil retaining protection device in deep foundation pit excavation, which comprises foundation pit soil and an L-shaped support plate, the top end of the support plate is fixedly connected with a plurality of second connecting seats, upper hydraulic support rods are hinged between the second connecting seats and the first connecting seats at the upper end, and lower hydraulic support rods are hinged between the first connecting seats and the second connecting seats at the lower end. A lower hydraulic supporting rod is hinged between the second connecting base located at the lower end and the first connecting base, a rotating shaft is fixedly connected to the inner end of the first connecting base, an upper outer steel rope and a lower outer steel rope penetrate through and are fixedly inserted into the supporting plate and the mounting steel frame, and corrugated pipes are clamped to the inner ends of the upper outer steel rope and the lower outer steel rope; a plurality of inner steel cable ropes are fixedly inserted into the inner ends of the corrugated pipes, and one ends of the inner steel cable ropes are fixedly connected with second rotating seats rotationally connected with the rotating shafts. Damping liquid slowly flows through holes of the piston blocks, instantaneous impact force is gradually released, and the situation that the upper outer steel cable rope and the lower outer steel cable rope are damaged due to too large instantaneous tension force is avoided.

Description

Technical Field

[0001] This invention relates to the field of foundation pit protection technology, specifically to a multi-segment linkage retaining and protection device for deep foundation pit excavation. Background Technology

[0002] In the fields of building construction (such as underground parking garages of super high-rise buildings and basements of large complexes), municipal engineering (such as open-cut sections of subway tunnels and underground integrated pipe corridors) and underground space development (such as underground commercial buildings and civil defense projects), deep foundation pit excavation is the core construction link connecting the above-ground structure and the underground foundation, and its excavation depth usually exceeds 5m. In the field of deep foundation pit excavation protection, traditional retaining devices often face the core pain points of "insufficient impact resistance and high maintenance risk": for sudden impacts such as the sudden surge of quicksand in the upper loose layer, existing protection relies mostly on rigid support or single steel cable tension, lacking an effective buffer structure. The instantaneous impact force can easily cause the steel cable to break due to the sudden increase in tension, leading to support failure. Therefore, it is necessary to propose a multi-segment linkage retaining protection device for deep foundation pit excavation. Summary of the Invention

[0003] To address the problems in the prior art, this invention provides a multi-segment linkage retaining and protection device for deep foundation pit excavation.

[0004] The technical solution adopted by the present invention to solve its technical problem is: a multi-segment linkage retaining and protection device for deep foundation pit excavation, including foundation pit soil and support plates arranged in an L shape, wherein the foundation pit soil includes an upper layer and a lower layer respectively; The side wall of the support plate is fixedly connected to several installation steel frames arranged in a crisscross pattern. Several first connecting seats are fixedly connected at the intersection of the installation steel frames. Several second connecting seats are fixedly connected to the top of the support plate. An upper hydraulic support rod is hinged between the second connecting seat and the first connecting seat at the upper end. A lower hydraulic support rod is hinged between the second connecting seat and the first connecting seat at the lower end. The first connecting seat has a rotating shaft fixedly connected to its inner end. The support plate and the mounting steel frame are fixedly connected to an upper outer steel cable and a lower outer steel cable. The inner ends of the upper outer steel cable and the lower outer steel cable are clamped with corrugated pipes. The inner ends of the corrugated pipes are fixedly inserted with several inner steel cables. One end of each of the several inner steel cables is fixedly connected to a second rotating seat that is rotatably connected to the rotating shaft. The inner ends of the corrugated pipes are slidably clamped with piston blocks, and the piston blocks are slidably connected to the inner steel cables. The outer walls of the piston blocks are perforated with holes.

[0005] Specifically, the upper layer and the lower layer are respectively the upper loose layer and the lower base layer, and both the upper layer and the lower layer are provided with a number of grouting holes with a diameter larger than that of the upper outer steel cable and the lower outer steel cable.

[0006] Specifically, the upper hydraulic support rod and the lower hydraulic support rod correspond to the upper layer and the lower layer, and the upper hydraulic support rod and the lower hydraulic support rod have different lengths.

[0007] Specifically, the upper hydraulic support rod and the lower hydraulic support rod are both fixedly connected to the top of the output end of the first rotating seat, and the first rotating seat is rotatably connected to the rotating shaft.

[0008] Specifically, the upper outer steel cable, the lower outer steel cable, and the grouting hole are all distributed in an inclined manner, and the outer ends of the upper outer steel cable, the lower outer steel cable, and the inner steel cable are fitted with nitrile rubber sleeves, and the corrugated pipe is made of nitrile rubber.

[0009] Specifically, a damping fluid inlet pipe is embedded at the other end of the bellows, and the inlet of the damping fluid inlet pipe is fitted with a sealing cap.

[0010] Specifically, the upper outer steel cable and the lower outer steel cable have different overall tilt angles and heights.

[0011] The first beneficial effect of this invention is that the upper and lower hydraulic support rods have different lengths, respectively adapting to the upper layer (upper loose layer) and the lower layer (lower base layer), enabling targeted transmission of support force—the former quickly suppresses the collapse and displacement of the loose layer, while the latter maintains the long-term bearing capacity of the base layer to prevent the support plate from tilting. Combined with upper and lower outer steel cables of different tilt angles and heights, along with nitrile rubber sleeves for corrosion protection and grouting hole anchoring, the inclined tension of the steel cables enhances the impact resistance of the loose layer while simultaneously offsetting the settlement pressure of the base layer, forming a dual protection of "layered support + tension," significantly improving the stability of protection in complex geological formations. The second beneficial effect of this invention is that the innovative integrated damping and buffer structure composed of a bellows and a piston block, combined with the linkage force design of the hydraulic rod and steel cable, effectively solves the pain points of traditional protection such as "insufficient impact resistance and high maintenance risk". When a sudden impact such as a sudden surge of quicksand occurs in the upper layer, the inner steel cable drives the piston block to slide inside the bellows, and the damping fluid flows slowly through the holes of the piston block, gradually releasing the instantaneous impact force and preventing damage to the upper and lower outer steel cables due to excessive instantaneous tension. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0013] Figure 1 A schematic diagram of the multi-segment linkage retaining and protection device for deep foundation pit excavation provided by the present invention. Figure 2 This is a schematic cross-sectional view of the multi-segment linkage retaining and protection device for deep foundation pit excavation provided by the present invention. Figure 3 The multi-segment linkage retaining wall protection device for deep foundation pit excavation provided by the present invention Figure 2Enlarged structural diagram at point A in the middle; Figure 4 A cross-sectional schematic diagram of the corrugated pipe structure of the multi-segment linkage retaining and protection device for deep foundation pit excavation provided by the present invention. Figure 5 A cross-sectional plan view of the corrugated pipe structure of the multi-segment linkage retaining wall protection device for deep foundation pit excavation provided by the present invention.

[0014] In the diagram: 1. Excavation pit soil; 2. Support plate; 10. Upper layer; 11. Lower layer; 21. Installation steel frame; 22. First connecting seat; 220. Rotating shaft; 23. Second connecting seat; 24. Upper hydraulic support rod; 240. Lower hydraulic support rod; 3. Upper outer steel cable; 4. Lower outer steel cable; 31. Corrugated pipe; 32. Inner steel cable; 33. Second rotating seat; 320. Piston block; 301. Hole; 101. Grouting hole; 241. First rotating seat; 310. Damping fluid inlet pipe; 311. Sealing sleeve cover. Detailed Implementation

[0015] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0016] like Figures 1-5 As shown, the present invention provides the following technical solution: Example 1: A multi-segment linkage retaining wall protection device for deep foundation pit excavation, including foundation pit soil 1 and L-shaped support plate 2. The foundation pit soil 1 includes an upper layer 10 and a lower layer 11. The side wall of the support plate 2 is fixedly connected with several crisscrossing installation steel frames 21. Several first connecting seats 22 are fixedly connected at the intersection of the installation steel frames 21. Several second connecting seats 23 are fixedly connected to the top of the support plate 2. An upper hydraulic support rod 24 is hinged between the upper second connecting seat 23 and the first connecting seat 22. A lower hydraulic support rod 240 is hinged between the lower second connecting seat 23 and the first connecting seat 22. The upper layer 10 and the lower layer 11 are the upper loose layer and the lower base layer, respectively. Several grouting holes 101 with a diameter larger than that of the upper outer steel cable 3 and the lower outer steel cable 4 are opened on the upper layer 10 and the lower hydraulic support rod 240. The upper hydraulic support rod 24 and the lower hydraulic support rod 240 correspond to the upper layer 10 and the lower layer 11, and the upper hydraulic support rod 24 and the lower hydraulic support rod 240 have different lengths.

[0017] Among them, by setting grouting holes 101 (with a diameter larger than the upper outer steel cable 3 and the lower outer steel cable 4), a channel is provided for the steel cable to be laid, and it is also convenient to inject grout into the stratum through the grouting holes 101 to reinforce the foundation pit soil 1 and improve the stability of the foundation pit sidewall. The upper hydraulic support rod 24 and the lower hydraulic support rod 240 correspond to the upper layer 10 and the lower layer 11 and have different lengths. They can be adapted to the height and stress requirements of different strata to ensure accurate transmission of support force to the upper layer 10 and the lower layer 11 and enhance the overall load-bearing capacity of the support plate 2. The first rotating seat 241 at the output top of the upper hydraulic support rod 24 and the lower hydraulic support rod 240 is rotatably connected to the rotating shaft 220, so that the hydraulic rod can adaptively adjust its angle with the slight displacement of the support plate 2, avoiding damage to the rod or connecting seat caused by rigid connection.

[0018] When using it, first determine the installation benchmark of L-shaped support plate 2 based on the excavation depth of the deep foundation pit. Then, attach the vertical section of support plate 2 to the side wall of the foundation pit and the horizontal section to the compacted foundation at the bottom of the foundation pit. Fix the bottom of support plate 2 to the bottom of the foundation pit with expansion bolts (which can be reinforced by backfilling soil later) to ensure that support plate 2 does not shake and provides a stable load-bearing carrier for the subsequent support structure.

[0019] Then, cement grout is injected into the pit sidewall through the pre-set grouting holes 101 in the upper layer 10 and lower layer 11 (the diameter is larger than that of the upper outer steel cable 3 and the lower outer steel cable 4, leaving space for subsequent steel cable installation). The cement grout fills the gaps between the loose layer particles, initially reinforcing the stratum until the support plate 2 is tightly attached to the pit sidewall, forming a stable retaining and protection system. When fixing the upper outer steel cable 3 and the lower outer steel cable 4 later, cement grout needs to be injected into their grouting holes 101. Before this, the upper outer steel cable 3 and the lower outer steel cable 4 need to be connected and fixed to avoid instability during grouting.

[0020] Example 2: The technical solution of this example, which differs from Example 1, includes: a rotating shaft 220 is fixedly connected to the inner end of the first connecting seat 22; an upper outer steel cable 3 and a lower outer steel cable 4 are fixedly inserted through the support plate 2 and the mounting steel frame 21; a corrugated pipe 31 is clamped to the inner end of the upper outer steel cable 3 and the lower outer steel cable 4; several inner steel cables 32 are fixedly inserted to the inner end of the corrugated pipe 31; a second rotating seat 33, which is rotatably connected to the rotating shaft 220, is fixedly connected to one end of each inner steel cable 32; a piston block 320 is slidably clamped to the inner end of each corrugated pipe 31, and the piston block 320 is slidably connected to the inner steel cable 32; and the outer wall of the piston block 320 is penetrated through... The upper hydraulic support rod 24 and the lower hydraulic support rod 240 are fixedly connected to the output top of the hole 301. The first rotating seat 241 is rotatably connected to the rotating shaft 220. The upper outer steel cable 3, the lower outer steel cable 4 and the grouting hole 101 are all distributed in an inclined manner. The outer ends of the upper outer steel cable 3, the lower outer steel cable 4 and the inner steel cable 32 are fitted with nitrile rubber sleeves. The corrugated pipe 31 is made of nitrile rubber. The other end of the corrugated pipe 31 is embedded with a damping liquid inlet pipe 310. The opening of the damping liquid inlet pipe 310 is fitted with a sealing cap 311. The upper outer steel cable 3 and the lower outer steel cable 4 have different overall inclination angles and heights.

[0021] Among them, the first rotating seat 241 at the output top of the upper hydraulic support rod 24 and the lower hydraulic support rod 240 is rotatably connected to the rotating shaft 220, so that the hydraulic rod can adaptively adjust the angle with the slight displacement of the support plate 2, avoiding damage to the rod or connecting seat caused by rigid connection; The damping fluid inlet pipe 310 on the bellows 31 is used to inject damping fluid, and the sealing cap 311 can ensure that the bellows 31 is sealed to prevent damping fluid leakage, ensure the normal operation of the damping buffer structure, and achieve effective buffering against sudden impacts. The upper outer steel cable 3 and the lower outer steel cable 4 have different inclination angles and heights, which can be adapted to the different geological characteristics and stress conditions of the upper layer 10 and the lower layer 11, so that the direction and force of the steel cable pull are more in line with the actual soil pressure distribution.

[0022] When in use, first open the sealing sleeve 311 of the damping fluid inlet pipe 310 on the bellows 31, inject damping fluid into the bellows 31, and after filling, tighten the sealing sleeve 311 to ensure that the inside of the bellows 31 is completely sealed. The inner steel cable 32 with a nitrile rubber sleeve is inserted into the bellows 31, so that the piston block 320 on the inner steel cable 32 fits tightly against the inner wall of the bellows 31, and the hole 301 on the outer wall of the piston block 320 is left as a flow channel for the damping fluid. The assembled corrugated pipe 31 is respectively clamped to the inner ends of the upper outer steel cable 3 and the lower outer steel cable 4. The upper outer steel cable 3 and the lower outer steel cable 4 are inclined to pass through the support plate 2 and the installation steel frame 21, and the other end is anchored into the stable stratum of the foundation pit soil 1 through the grouting hole 101. At the same time, the second rotating seat 33 at one end of the inner steel cable 32 is rotatably connected to the rotating shaft 220 at the inner end of the first connecting seat 22. The first rotating seat 241 at the output end of the upper hydraulic support rod 24 and the lower hydraulic support rod 240 is also sleeved on the rotating shaft 220 to form a cooperative force.

[0023] When a sudden impact such as a quicksand surge occurs in the upper layer 10 (loose layer), the impact load pushes the support plate 2 to shift, which in turn pulls the inner steel cable 32. The inner steel cable 32 drives the piston block 320 to move inside the corrugated pipe 31. The damping fluid inside the corrugated pipe 31 is squeezed and can only flow slowly through the holes 301 of the piston block 320, forming a damping force that "holds" the inner steel cable 32, slowly releasing the impact force and preventing the upper outer steel cable 3 and the lower outer steel cable 4 from breaking due to excessive instantaneous tension. Moreover, the corrugated pipe 31 is completely sealed, and cement slurry will not enter the pipe during grouting, thus not affecting the operation of the buffer structure.

[0024] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-segment linkage retaining and protection device for deep foundation pit excavation, comprising foundation pit soil (1) and support plate (2) arranged in an L shape, wherein the foundation pit soil (1) comprises an upper layer (10) and a lower layer (11). Its features are, The side wall of the support plate (2) is fixedly connected to a number of installation steel frames (21) arranged in a crisscross pattern. A number of first connecting seats (22) are fixedly connected at the intersection of the installation steel frames (21). A number of second connecting seats (23) are fixedly connected to the top of the support plate (2). An upper hydraulic support rod (24) is hinged between the second connecting seat (23) and the first connecting seat (22) at the upper end. A lower hydraulic support rod (240) is hinged between the second connecting seat (23) and the first connecting seat (22) at the lower end. The first connecting seat (22) is fixedly connected to the inner end of the rotating shaft (220). The support plate (2) and the mounting steel frame (21) are fixedly connected to the upper outer steel cable (3) and the lower outer steel cable (4). The inner ends of the upper outer steel cable (3) and the lower outer steel cable (4) are clamped with the corrugated pipe (31). The inner ends of the corrugated pipe (31) are fixedly connected with several inner steel cables (32). One end of several inner steel cables (32) is fixedly connected to a second rotating seat (33) that is rotatably connected to the rotating shaft (220). The inner ends of the corrugated pipe (31) are slidably clamped with piston blocks (320), and the piston blocks (320) are slidably connected to the inner steel cables (32). The outer wall of the piston blocks (320) is provided with holes (301).

2. The multi-segment linkage retaining wall protection device for deep foundation pit excavation according to claim 1, characterized in that: The upper layer (10) and the lower layer (11) are respectively the upper loose layer and the lower base layer. Both the upper layer (10) and the lower layer (11) have several grouting holes (101) with a diameter larger than that of the upper outer steel cable (3) and the lower outer steel cable (4).

3. The multi-segment linkage retaining wall protection device for deep foundation pit excavation according to claim 1, characterized in that: The upper hydraulic support rod (24) and the lower hydraulic support rod (240) correspond to the upper layer (10) and the lower layer (11), and the upper hydraulic support rod (24) and the lower hydraulic support rod (240) have different lengths.

4. The multi-segment linkage retaining wall protection device for deep foundation pit excavation according to claim 1, characterized in that: The upper hydraulic support rod (24) and the lower hydraulic support rod (240) are both fixedly connected to the top of the output end of the first rotating seat (241), and the first rotating seat (241) is rotatably connected to the rotating shaft (220).

5. The multi-segment linkage retaining wall protection device for deep foundation pit excavation according to claim 1, characterized in that: The upper outer steel cable (3), the lower outer steel cable (4), and the grouting hole (101) are all distributed in an inclined manner. The outer ends of the upper outer steel cable (3), the lower outer steel cable (4), and the inner steel cable (32) are fitted with nitrile rubber sleeves, and the corrugated pipe (31) is made of nitrile rubber.

6. The multi-segment linkage retaining wall protection device for deep foundation pit excavation according to claim 1, characterized in that: The other end of the bellows (31) is embedded with a damping fluid inlet pipe (310), and the inlet of the damping fluid inlet pipe (310) is fitted with a sealing cap (311).

7. The multi-segment linkage retaining and protection device for deep foundation pit excavation according to claim 1, characterized in that: The upper outer steel cable (3) and the lower outer steel cable (4) have different overall tilt angles and heights.

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