Civil construction foundation pit anti-collapse supporting device and installation adjusting method

Abstract

The application provides a civil construction foundation pit anti-collapse supporting device and a mounting and adjusting method. The supporting device is composed of multiple supporting units. Each supporting unit comprises two oppositely arranged supporting plates. An electric telescopic cylinder is horizontally arranged between the two supporting plates. One end of the electric telescopic cylinder is connected with one of the supporting plates. A first pressure sensor is arranged on the connecting surface. A second pressure sensor is arranged on the other supporting plate near the outer side of the foundation pit wall. A siphon drainage device is arranged on the top of one of the supporting plates. Two adjacent supporting units are connected through a tensioning mechanism. The application can make two adjacent supporting plates tightly abut together through the tensioning mechanism, avoid the generation of gaps, and cause the unevenness of the foundation pit sidewall and the seepage. The siphon effect can realize the rapid drainage of the foundation pit. During installation, the supporting force of the two supporting plates can be automatically adjusted according to the real-time collected foundation pit sidewall pressure, displacement and underground water level data.

Description

A collapse prevention support device for foundation pits in civil construction and its installation and adjustment method Technical Field

[0001] This invention relates to the field of foundation pit collapse prevention technology, and in particular to a foundation pit collapse prevention support device and its installation and adjustment method in civil engineering construction. Background Technology

[0002] When excavating a foundation pit, it is necessary to support it to ensure the safety of underground structure construction and the surrounding environment. This involves the use of retaining, reinforcement, and protection measures for the sidewalls and surrounding environment of the foundation pit.

[0003] Existing foundation pit support devices all include support plates and support frames. The support plates are tightly attached to the foundation pit wall, and the support frames support the support plates. However, the stability of the support plates in existing support devices is poor, resulting in unsatisfactory support effects. Furthermore, the operation of disassembly and assembly is extremely cumbersome, which is not conducive to the transportation and reuse of the support frames. In order to improve the support effect of the support plates and solve the problem of easy disassembly and assembly, patent publication number CN216586587U discloses a foundation pit anti-collapse support device for civil construction, which includes a left support plate, a right support plate, an adjustable support structure, and a first fixing bolt. The left and right support plates are respectively tightly attached to the opposite foundation pit wall, and the two support plates are supported simultaneously by adjusting the support structure. This support device has the advantages of stable support and convenient installation and operation.

[0004] However, the aforementioned support devices cannot effectively drain water during use, which can easily lead to a large amount of water accumulating inside the foundation pit during rainy weather. This is not conducive to subsequent construction and can also cause instability in the foundation pit structure, posing a risk of foundation pit collapse. Secondly, the lack of reinforcement devices between adjacent support devices can easily lead to gaps between adjacent support plates, causing the sidewalls of the foundation pit to become misaligned due to pressure, resulting in unevenness of the foundation pit sidewalls.

[0005] In addition, the adjustment support structure of the above-mentioned support device cannot be controlled during adjustment, and the adjustment effect cannot be guaranteed. The support force of the two support plates cannot be controlled, which can easily lead to over-support or under-support. Both over-support and under-support can cause the pit wall to collapse. Summary of the Invention

[0006] This invention provides a support device for preventing collapse of foundation pits in civil construction and an installation and adjustment method. The support device can ensure the stability of the support and effectively achieve drainage in the foundation pit. Through calculation and adjustment, it can avoid the problems of over-support or under-support during installation.

[0007] To solve the above-mentioned technical problems, the present invention provides a support device for preventing collapse of foundation pits in civil construction. The support device is composed of multiple support units. Each support unit includes two support plates arranged opposite each other. An electric telescopic cylinder is horizontally arranged between the two support plates. One end of the electric telescopic cylinder is connected to one of the support plates and a first pressure sensor is provided on the connection surface. A second pressure sensor is provided on the outer side of the other support plate near the foundation pit wall. A siphon drainage device is provided on the top of one of the support plates. Adjacent support units are connected by a tensioning mechanism.

[0008] The siphon drainage device includes an air suction box fixedly connected to the top of one of the support plates. The bottom of the air suction box is fixedly connected to a liquid suction pipe and a liquid outlet pipe. The liquid suction pipe is located between the two support plates, and its bottom end extends vertically downward to the lower part of the support plate. A filter screen is provided at the bottom end of the liquid suction pipe. The liquid outlet pipe is located on the outside of the support plate away from the liquid suction pipe. The air suction box is equipped with a liquid suction device.

[0009] The tensioning mechanism includes a fastening threaded cylinder and two fixing plates. Both ends of the fastening threaded cylinder are threadedly connected to fastening threaded rods. The two fixing plates are respectively fixed to two adjacent support plates on the same side. The ends of the two fastening threaded rods away from the fastening threaded cylinder are connected to the fixing plates on the corresponding sides.

[0010] A preferred technical solution of the present invention: The support device further includes a controller, wherein a laser displacement sensor and a liquid level sensor are installed on the inner side of one of the support plates away from the pit wall, and the signal output terminals of the first pressure sensor, the second pressure sensor, the laser displacement sensor, and the liquid level sensor are all connected to the signal input terminal of the controller, and the signal output terminal of the controller is connected to the control terminal of the electric telescopic cylinder; the controller is provided with a support force adjustment unit, which controls the extension and retraction of the electric telescopic cylinder according to the real-time collected data of pit sidewall pressure, displacement, and groundwater level, and automatically adjusts the support force of the two support plates.

[0011] A preferred technical solution of the present invention: The liquid aspiration device includes a piston plate, which is slidably connected inside the suction box. A rubber ring is provided on the outer side wall of the piston plate. A sliding rod is fixedly connected to the upper side of the piston plate. The sliding rod passes through the upper side wall of the suction box. A top plate is fixedly connected to the upper end of the sliding rod. A spring is sleeved on the sliding rod. The two ends of the spring abut against the top plate and the side wall of the suction box, respectively. The outlet pipe has a detachable sealing cap at its port. The lower end of the liquid aspiration pipe extends to the bottom end of the support plate.

[0012] The preferred technical solution of the present invention is as follows: the other end of each fastening threaded rod is fixedly connected to an insert plate, and the top of each fixed plate is provided with a slot adapted to the shape of the insert plate. A strip groove is provided on the side wall of the slot, and the width of the strip groove is adapted to the diameter of the fastening threaded rod. The two fastening threaded rods are respectively inserted into the slots on the corresponding side fixed plates through the insert plates at their ends.

[0013] The preferred technical solution of the present invention is as follows: each of the support plates has a rubber layer at both ends, and each of the support plates has a plurality of insert rods fixedly connected to its bottom end, and the bottom end of each insert rod is tapered.

[0014] A preferred technical solution of the present invention is as follows: the controller is equipped with a foundation pit collapse risk assessment unit, which is used to assess the foundation pit collapse risk according to the risk assessment formula.

[0015] To achieve the above-mentioned technical objectives, the present invention also provides an installation and adjustment method for a foundation pit anti-collapse support device in civil engineering construction, characterized by the following steps:

[0016] S1. Install multiple support units in the foundation pit. The two support plates of each support unit are attached to the two opposite side walls of the foundation pit. The two adjacent support plates on the same side of two adjacent support units are connected by a tensioning mechanism.

[0017] S2. The support pressure of the two support plates is collected in real time by first and second pressure sensors installed on the support plates. and the stress on the sidewalls of the foundation pit The relative displacement increment of the two support plates is collected in real time by a laser displacement sensor. The extension and retraction of the electric telescopic cylinder are controlled by a dynamic adjustment formula for support stiffness, thereby dynamically adjusting the support strength of the two support plates. The dynamic adjustment formula for support stiffness is as follows:

[0018]

[0019] In the formula: To provide support at the current moment; Initial support strength; This represents the current stress on the sidewall of the foundation pit. This represents the ultimate stress of the support plate material. This represents the relative displacement increment between the two support plates; The allowable displacement threshold for the two support plates; These are the weighting coefficients;

[0020] S3. When water accumulates in the foundation pit, the water in the foundation pit is first introduced into the suction pipe through the suction device. Then, under the siphon effect, the water in the foundation pit will be discharged from the outlet pipe along the suction pipe and the air suction box, so as to realize the rapid drainage of the foundation pit.

[0021] The preferred technical solution of the present invention is as follows: In step S1, the tightening connection process of two adjacent support plates on the same side is as follows: The insert plates at both ends of the fastening threaded cylinder are respectively inserted into the fixing plates on the two adjacent support plates on the same side. After the insert plates are inserted into the slots on the fixing plates, the fastening threaded rods can slide along the strip groove to the bottom. Then, the fastening threaded cylinder is grasped and twisted so that the two fastening threaded rods are close to each other and aligned, thereby making the two adjacent support plates press tightly together and improving the sealing between the two adjacent support plates.

[0022] A further technical solution of the present invention: In step S2, when adjusting the support strength of the two support plates, the water level in the foundation pit is collected in real time by a liquid level sensor. The risk of foundation pit collapse is assessed using a risk assessment formula based on the foundation pit collapse risk assessment unit. The risk assessment formula is as follows:

[0023]

[0024] As a risk assessment index, ; This represents the current water level within the foundation pit. This is the dangerous water level threshold. These are the weighting coefficients.

[0025] The preferred technical solution of the present invention is as follows: In step S3, the liquid suction device includes a piston plate, a sliding rod, a top plate, and a spring; the working process of the liquid suction device is as follows: the top plate is grasped and the piston plate is driven to descend by the sliding rod. The descent of the piston plate can discharge the air in the suction box through the liquid suction pipe. Afterwards, the piston plate rises back under the action of the spring, and the liquid suction pipe sucks the water in the foundation pit into the suction box. Then, the sealing cap at the bottom of the liquid outlet pipe can be unscrewed. At this time, the water in the foundation pit will be continuously discharged from the liquid outlet pipe along the liquid suction pipe and the suction box under the siphon effect, realizing the rapid drainage of the foundation pit.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. This invention not only allows two adjacent support plates to be tightly pressed together, improving the sealing between the two adjacent support plates and avoiding gaps that could cause unevenness of the pit sidewalls and water seepage, but also allows the water accumulated in the pit to be continuously discharged from the outlet pipe along the suction pipe and air suction box through the siphon effect, thus achieving rapid drainage of the pit.

[0028] 2. This invention can dynamically adjust the support strength of the two support plates to avoid over-support or under-support; at the same time, the controller also assesses the risk of foundation pit collapse through the foundation pit collapse risk assessment unit. If the foundation pit collapse risk assessment index exceeds the preset threshold, the controller can issue an alarm.

[0029] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Specific embodiments of the present invention are given in detail below with reference to the accompanying drawings. Attached Figure Description

[0030] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0031] Figure 1 is a schematic diagram of the structure of the civil engineering foundation pit anti-collapse support device in this invention;

[0032] Figure 2 is a schematic diagram of the structure of a single support unit in this invention;

[0033] Figure 3 is a schematic diagram of the structure between the two fixing plates in this invention;

[0034] Figure 4 is a schematic diagram of the fastening threaded cylinder and two fastening threaded rods in this invention.

[0035] Figure 5 is a schematic diagram of the structure of the fixing plate in this invention;

[0036] Figure 6 is a top view cross-sectional structural diagram of a single support unit in this invention;

[0037] Figure 7 is a frontal cross-sectional structural diagram of the present invention;

[0038] Figure 8 is a frontal cross-sectional view of the intake box in this invention.

[0039] In the attached image:

[0040] 1. Fixed plate; 2. Fastening threaded rod; 3. Fastening threaded cylinder; 4. Electric telescopic cylinder; 5. First pressure sensor; 6. Top plate; 7. Suction box; 8. Support plate; 9. Insert rod; 10. Rubber layer; 11. Insert plate; 12. Strip groove; 13. Slot; 14. Suction tube; 15. Sliding rod; 16. Spring; 17. Piston plate; 18. Discharge tube; 19. Sealing cap; 20. Laser displacement sensor; 21. Liquid level sensor; 22. Second pressure sensor. Detailed Implementation

[0041] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0042] Please refer to Figures 1 to 8. The civil engineering foundation pit anti-collapse support device provided in this embodiment is composed of multiple support units. Each support unit includes two support plates 8 arranged opposite each other. Each support plate 8 has a rubber layer 10 at both ends. Multiple insertion rods 9 are fixedly connected to the bottom end of each support plate 8. The bottom end of each insertion rod 9 is tapered to facilitate insertion into the bottom of the foundation pit to fix the support plate 8. An electric telescopic cylinder 4 is horizontally arranged between the two support plates 8. One end of the electric telescopic cylinder 4 is connected to one of the support plates 8 and a first pressure sensor 5 is provided on the connection surface. A second pressure sensor 22 is provided on the outer side of the other support plate 8 near the foundation pit wall. A siphon drainage device is provided on the top of one of the support plates 8. Adjacent support units are connected by a tensioning mechanism.

[0043] In this embodiment, as shown in Figures 7 and 8, the siphon drainage device includes an air intake box 7 fixedly connected to the top of one of the support plates 8. A suction pipe 14 and an outlet pipe 18 are fixedly connected to the bottom of the air intake box 7. The suction pipe 14 is located between the two support plates 8, with its bottom end extending vertically downwards to the lower part of the support plate. A filter screen is provided at the bottom end of the suction pipe 14. The outlet pipe 18 is located on the outer side of the support plate 8 away from the suction pipe 14. A suction device is provided inside the air intake box 7; the suction device includes a piston plate 17. The piston plate 17 is slidably connected inside the suction box 7. A rubber ring is provided on the outer side wall of the piston plate 17. A sliding rod 15 is fixedly connected to the upper side of the piston plate 17. The sliding rod 15 passes through the upper side wall of the suction box 7. A top plate 6 is fixedly connected to the upper end of the sliding rod 15. A spring 16 is sleeved on the sliding rod 15. The two ends of the spring 16 abut against the top plate 6 and the side wall of the suction box 7, respectively. The port of the liquid outlet pipe 18 is provided with a detachable sealing cap 19. The lower end of the liquid suction pipe 14 extends to the bottom end of the support plate 8.

[0044] In the embodiment, as shown in Figures 3 to 6, the tensioning mechanism includes a fastening threaded cylinder 3 and two fixing plates 1. Both ends of the fastening threaded cylinder 3 are threadedly connected to fastening threaded rods 2. The two fixing plates 1 are respectively fixed to two adjacent support plates 8 on the same side. The ends of the two fastening threaded rods 2 away from the fastening threaded cylinder 3 are connected to the corresponding fixing plates 1. The other end of each fastening threaded rod 2 is fixedly connected to an insert plate 11, and each fixing plate 1 has a slot 13 on its top that matches the shape of the insert plate 11. A strip groove 12 is formed on the side wall of the slot 13, and the width of the strip groove 12 matches the diameter of the fastening threaded rod 2. The two fastening threaded rods 2 are inserted into the slots 13 on the corresponding fixing plates 1 through the insert plates 11 at their ends.

[0045] In this embodiment, the support device further includes a controller. A laser displacement sensor 20 and a liquid level sensor 21 are installed on the inner side of one of the support plates 8 away from the pit wall. The signal output terminals of the first pressure sensor 5, the second pressure sensor 22, the laser displacement sensor 20, and the liquid level sensor 21 are all connected to the signal input terminal of the controller. The signal output terminal of the controller is connected to the control terminal of the electric telescopic cylinder 4. The controller is equipped with a support force adjustment unit, which controls the extension and retraction of the electric telescopic cylinder 4 based on real-time collected data on the pit sidewall pressure, displacement, and groundwater level, automatically adjusting the support force of the two support plates 8. The controller is also equipped with a pit collapse risk assessment unit, which is used to assess the pit collapse risk according to a risk assessment formula.

[0046] The support force adjustment unit collects the support pressure of the two support plates 8 in real time through the first pressure sensor 5, the second pressure sensor 22, the laser displacement sensor 20, and the liquid level sensor 21. stress on the sidewalls of the foundation pit The relative displacement increment of the two support plates 8 Groundwater level The extension and retraction of the electric telescopic cylinder 4 is controlled by the dynamic adjustment formula of the support stiffness, so as to dynamically adjust the support force of the two support plates 8 and avoid over-support or under-support. The controller is equipped with a foundation pit collapse risk assessment unit, which is used to assess the foundation pit collapse risk according to the risk assessment formula.

[0047] The installation and adjustment method of the civil engineering foundation pit anti-collapse support device in the embodiment includes the following steps:

[0048] S1. First, the two opposing support plates 8 can be placed in the pit so that the two opposing support plates 8 adapt to the width of the pit and abut against the two side walls of the pit. The two adjacent support plates on the same side of the two adjacent support units are connected by a tensioning mechanism. Specifically, the insert plates 11 at both ends of the fastening threaded cylinder 3 are inserted into the fixing plates 1 on the two adjacent support plates 8 respectively. After the insert plates 11 are inserted into the slots 13 on the fixing plates 1, the fastening threaded rods 2 can slide along the strip grooves 12 to the bottom. Then, the fastening threaded cylinder 3 is grasped and twisted so that the two fastening threaded rods 2 are close to each other and aligned, thereby making the two adjacent support plates 8 press tightly together and improving the sealing between the two adjacent support plates 8.

[0049] S2. The support pressure of the two support plates is collected in real time by first and second pressure sensors installed on the support plates. and the stress on the sidewalls of the foundation pit The relative displacement increment of the two support plates is collected in real time by a laser displacement sensor. The extension and retraction of the electric telescopic cylinder are controlled by a dynamic adjustment formula for support stiffness, thereby dynamically adjusting the support strength of the two support plates. The dynamic adjustment formula for support stiffness is as follows:

[0050]

[0051] In the formula: To provide support at the current moment; Initial support strength; This represents the current stress on the sidewall of the foundation pit. This represents the ultimate stress of the support plate material. This represents the relative displacement increment between the two support plates; The allowable displacement threshold for the two support plates; These are the weighting coefficients;

[0052] While adjusting the support strength of the two support plates, the controller simultaneously assesses the risk of foundation pit collapse through the foundation pit collapse risk assessment unit.

[0053] In step S2, while adjusting the support strength of the two support plates, the controller simultaneously assesses the risk of foundation pit collapse through the foundation pit collapse risk assessment unit. If the foundation pit collapse risk assessment index... If the threshold is exceeded, the controller can issue an alarm to facilitate the dispatch of personnel to investigate the risk. The risk assessment formula is as follows:

[0054]

[0055] As a risk assessment index, ; This represents the current water level within the foundation pit. This is the dangerous water level threshold. These are the weighting coefficients.

[0056] S3. When water accumulates in the foundation pit, grasp the top plate 6 and use the sliding rod 15 to drive the piston plate 17 down. The piston plate 17 descends and discharges the air in the suction box 7 through the suction pipe 14. After the piston plate 17 rises under the action of the spring 16, the suction pipe 14 can suck the water in the foundation pit into the suction box 7. Then, the sealing cap 19 at the bottom of the outlet pipe 18 can be unscrewed. At this time, the water in the foundation pit will be continuously discharged from the outlet pipe 18 along the suction pipe 14 and the suction box 7 under the siphon effect, realizing the rapid drainage of the foundation pit.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any equivalent changes, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A foundation pit anti-collapse support device for civil engineering construction, characterized in that: The support device is composed of multiple support units. Each support unit includes two opposing support plates (8). An electric telescopic cylinder (4) is horizontally arranged between the two support plates (8). One end of the electric telescopic cylinder (4) is connected to one of the support plates (8), and a first pressure sensor (5) is provided on the connection surface. A second pressure sensor (22) is provided on the outer side of the support plate (8) near the pit wall. A siphon drainage device is provided on the top of one of the support plates (8). Adjacent support units are connected by a tensioning mechanism. The siphon drainage device includes an air suction box (7) fixedly connected to the top of one of the support plates (8). A suction pipe (14) is fixedly connected to the bottom of the air suction box (7). The liquid outlet pipe (18) and the liquid suction pipe (14) are located between the two support plates (8), with their bottom ends extending vertically downwards to the lower part of the support plates. A filter screen is provided at the bottom end of the liquid suction pipe (14). The liquid outlet pipe (18) is located on the outside of the support plate (8) away from the liquid suction pipe (14). The suction box (7) is equipped with a liquid suction device. The tensioning mechanism includes a fastening threaded cylinder (3) and two fixing plates (1). Both ends of the fastening threaded cylinder (3) are threadedly connected to fastening threaded rods (2). The two fixing plates (1) are respectively fixed on two adjacent support plates (8) on the same side. The ends of the two fastening threaded rods (2) away from the fastening threaded cylinder (3) are connected to the fixing plates (1) on the corresponding side. The support device also includes a controller, in which one A laser displacement sensor (20) and a liquid level sensor (21) are installed on the inner side of the side support plate (8) away from the foundation pit wall. The signal output terminals of the first pressure sensor (5), the second pressure sensor (22), the laser displacement sensor (20), and the liquid level sensor (21) are all connected to the signal input terminal of the controller. The signal output terminal of the controller is connected to the control terminal of the electric telescopic cylinder (4). The controller is equipped with a support force adjustment unit. The support force adjustment unit controls the extension and retraction of the electric telescopic cylinder (4) based on the real-time collected data of foundation pit side wall pressure, displacement, and groundwater level, and automatically adjusts the support force of the two support plates (8). The controller is equipped with a foundation pit collapse risk assessment unit. The foundation pit collapse risk assessment unit is used to assess the foundation pit collapse risk. The risk of pit collapse is assessed according to the risk assessment formula; the liquid suction device includes a piston plate (17), which is slidably connected in the suction box (7). A rubber ring is provided on the outer side wall of the piston plate (17). A sliding rod (15) is fixedly connected to the upper side of the piston plate (17). The sliding rod (15) passes through the upper side wall of the suction box (7). A top plate (6) is fixedly connected to the upper end of the sliding rod (15). A spring (16) is sleeved on the sliding rod (15). The two ends of the spring (16) abut against the top plate (6) and the side wall of the suction box (7) respectively; the port of the liquid outlet pipe (18) is provided with a detachable sealing cap (19). The lower end of the liquid suction pipe (14) extends to the bottom end of the support plate (8);Each threaded rod (2) is fixedly connected to an insert plate (11) at its other end, and each fixed plate (1) has a slot (13) on its top that matches the shape of the insert plate (11). A strip groove (12) is formed on the side wall of the slot (13), and the width of the strip groove (12) matches the diameter of the threaded rod (2). Two threaded rods (2) are respectively inserted into the slots (13) on the corresponding side fixed plates (1) through the insert plates (11) at their ends.

2. The anti-collapse support device for foundation pits in civil construction according to claim 1, characterized in that: Each of the support plates (8) has a rubber layer (10) at both ends, and a plurality of insert rods (9) are fixedly connected to the bottom end of each support plate (8), with the bottom end of each insert rod (9) being tapered.

3. A method for installing and adjusting a civil engineering foundation pit anti-collapse support device as described in claim 1 or 2, characterized in that, Specifically, the following steps are included: S1. Multiple support units are installed in the foundation pit. The two support plates of each support unit are pressed against the two opposite side walls of the foundation pit. Adjacent support plates on the same side of two adjacent support units are connected by a tensioning mechanism. S2. The support pressure of the two support plates is collected in real time by a first pressure sensor and a second pressure sensor installed on the support plates. and the stress on the sidewalls of the foundation pit The relative displacement increment of the two support plates is collected in real time by a laser displacement sensor. The extension and retraction of the electric telescopic cylinder are controlled by a dynamic adjustment formula for support stiffness, thereby dynamically adjusting the support strength of the two support plates. The dynamic adjustment formula for support stiffness is as follows: In the formula: To provide support at the current moment; Initial support strength; This represents the current stress on the sidewall of the foundation pit. This represents the ultimate stress of the support plate material. This represents the relative displacement increment between the two support plates; The allowable displacement threshold for the two support plates; S3. When water accumulates in the foundation pit, the water in the foundation pit is first introduced into the suction pipe through the suction device. Then, under the siphon effect, the water in the foundation pit will be discharged from the outlet pipe along the suction pipe and the air suction box, so as to realize the rapid drainage of the foundation pit.

4. The installation and adjustment method of the foundation pit anti-collapse support device for civil construction according to claim 3, characterized in that, In step S1, the tightening connection process of two adjacent support plates on the same side is as follows: insert the insert plates at both ends of the fastening threaded cylinder into the fixing plates on the two adjacent support plates on the same side respectively. After the insert plates are inserted into the slots on the fixing plates, the fastening threaded rod slides along the strip groove to the bottom. Then, grasp the fastening threaded cylinder and twist it so that the two fastening threaded rods come closer to each other and align, thereby making the two adjacent support plates press tightly together and improving the sealing between the two adjacent support plates.

5. The installation and adjustment method of a civil engineering foundation pit anti-collapse support device according to claim 3, characterized in that: In step S2, when adjusting the support strength of the two support plates, the water level in the pit is collected in real time using a liquid level sensor. The risk of foundation pit collapse is assessed using a risk assessment formula based on the foundation pit collapse risk assessment unit. The risk assessment formula is as follows: ； As a risk assessment index, ； This represents the current water level within the foundation pit. This is the dangerous water level threshold. These are the weighting coefficients.

6. The installation and adjustment method of the foundation pit anti-collapse support device for civil construction according to claim 3, characterized in that: In step S3, the working process of the liquid suction device is as follows: Grasp the top plate and drive the piston plate down through the sliding rod. The piston plate descends and discharges the air in the suction box through the liquid suction pipe. After that, the piston plate rises back under the action of the spring, and the liquid suction pipe sucks the water in the pit into the suction box. Then, unscrew the sealing cap at the bottom of the liquid outlet pipe. At this time, the water in the pit will be continuously discharged from the liquid outlet pipe along the liquid suction pipe and the suction box under the siphon effect, realizing the rapid drainage of the pit.

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