Deep foundation pit displacement monitoring device and monitoring method

Abstract

The invention relates to the technical field of foundation pit monitoring, and provides a deep foundation pit displacement monitoring device which comprises an inhaul cable, a sleeve, a telescopic mechanism and a magnetostrictive displacement sensor, the two ends of the inhaul cable are anchored between the inner side wall of a foundation pit and the inner bottom wall of the foundation pit through anchoring mechanisms, and the inhaul cable is in a tightened state; the telescopic mechanism comprises a fixed seat and a telescopic assembly connected with the fixed seat, the fixed seat is fixed in the foundation pit, and the sleeve is fixed to the end, away from the fixed seat, of the telescopic assembly; the sleeve is provided with an axial through hole, and the inhaul cable is arranged in the through hole in a penetrating mode. The magnetostrictive displacement sensor comprises a sensor body and a movable magnetic ring, the sensor body is installed on the sleeve or the telescopic assembly, and the movable magnetic ring is correspondingly installed on the telescopic assembly or the sleeve. On the basis, the accuracy of monitoring operation can be effectively improved, and it is ensured that displacement of the side wall of the foundation pit can be known in time. In addition, the invention further provides a monitoring method based on the deep foundation pit displacement monitoring device.

Description

Technical Field

[0001] This application relates to the field of foundation pit monitoring technology, and in particular to a deep foundation pit displacement monitoring device and monitoring method. Background Technology

[0002] Deep foundation pits are temporary structures formed for the safe construction of underground structures. They are a prerequisite for the development of underground space, such as the construction of underground parking stations, subway stations, municipal integrated pipe corridors, and urban underground complexes.

[0003] The existing Chinese patent with publication number CN113309110A discloses an automatic monitoring system for foundation pit displacement, including a fixing mechanism, an anchoring mechanism, and a monitoring mechanism. The fixing mechanism is fixed to the inner sidewall of the foundation pit, and the anchoring mechanism is fixed to the inner bottom wall of the foundation pit. A cable is provided between the fixing mechanism and the anchoring mechanism. The cable is in a taut state, and the monitoring mechanism is fixed to the cable and is used to detect the tension change of the cable, thereby enabling the monitoring of the displacement of the foundation pit sidewall.

[0004] Specifically, the monitoring mechanism includes a monitoring base and a monitoring support, with the support fixed to the base. The support has a through-slot for the cable to pass through, and a pressure sensor is installed inside the through-slot. The pressure sensor is connected to an abutment roller via a buffer spring. By observing the pressure sensor readings, displacement of the pit sidewall can be detected. The monitoring base has open slots at both ends for the cable to pass through, and a slider is installed inside each slot. A limiting roller is located at the end of the slider closest to the cable. The combined action of the limiting roller and the abutment roller enhances the anti-sway performance of the monitoring base against the cable, making the base more stable and improving the effectiveness of pit displacement monitoring.

[0005] However, the force exerted by the limiting roller on the cable during monitoring operations requires a high level of precision. If the force exerted by the limiting roller on the cable is greater than the elastic force of the buffer spring, displacement of the pit sidewall may occur, but the cable section located inside the monitoring platform may remain taut, making it difficult to effectively monitor the displacement of the pit sidewall. Conversely, if the force exerted by the limiting roller on the cable is less than the force of the buffer spring, the monitoring mechanism may slide to the bottom of the cable under its own weight. The small change in tension at the bottom of the cable will also affect the accuracy of the pit sidewall displacement monitoring. Therefore, using the monitoring system described above for real-time monitoring of pit sidewall displacement carries the risk of inaccurate monitoring results, posing a safety hazard and requiring improvement. Summary of the Invention

[0006] Based on this, this application provides a deep foundation pit displacement monitoring device and monitoring method, which can effectively improve the accuracy of monitoring operations and ensure that displacement of the foundation pit sidewall can be detected in a timely manner.

[0007] Firstly, the deep foundation pit displacement monitoring device provided in this application adopts the following technical solution: A deep foundation pit displacement monitoring device includes a cable, a sleeve, a telescopic mechanism and a magnetostrictive displacement sensor. Anchoring mechanisms are provided at both ends of the cable. The cable is anchored between the inner side wall and the bottom wall of the foundation pit through the anchoring mechanisms, and the cable is in a taut state. The telescopic mechanism includes a fixed base and a telescopic component connected thereto. The fixed base is fixed inside the pit, and the sleeve is fixed at the end of the telescopic component away from the fixed base. The sleeve has an axially through hole through which the cable passes. The magnetostrictive displacement sensor includes a sensor body and a movable magnetic ring that cooperates with it. The sensor body is mounted on a sleeve or telescopic assembly, and the movable magnetic ring is correspondingly mounted on the telescopic assembly or sleeve.

[0008] By adopting the above technical solution, and by setting a cable anchored between the inner wall and the bottom wall of the foundation pit, the taut cable keeps the telescopic component extended. By calibrating and zeroing the magnetostrictive displacement sensor, the displacement value of the inner wall of the foundation pit can be measured. During construction, when the inner wall of the foundation pit shifts, the cable becomes slack, and the sleeve, under its own weight, forces the telescopic component to retract inward. This causes relative movement between the moving magnetic ring and the sensor body, resulting in a change in the measured value of the magnetostrictive displacement sensor. This change sends a numerical signal to the backend monitoring information processing unit, which processes the signal and displays it or issues an alarm to alert construction personnel to the occurrence of foundation pit displacement. Therefore, the monitoring device of this application effectively improves the accuracy of monitoring operations and has the advantage of rapid response, ensuring timely detection of foundation pit sidewall displacement.

[0009] Optionally, the telescopic assembly includes a first connecting post and a second connecting post that are nested together, and an anti-detachment structure is provided between the first connecting post and the second connecting post; The first connecting post is connected to the sleeve, and the second connecting post is rotatably connected to the fixed base; the sensor body is mounted on the sleeve or the second connecting post, and the movable magnetic ring is correspondingly mounted on the second connecting post or the sleeve; A steering retaining structure is provided between the second connecting column and the fixed seat to position the rotation angle between the telescopic component and the fixed seat.

[0010] By adopting the above technical solution, and by setting the first and second connecting columns that are nested together, the distance between the sleeve and the fixed seat can be adjusted. Furthermore, by rotating the telescopic component and the fixed seat to maintain the rotation angle between them, the cable and the telescopic component can be kept perpendicular to each other. This allows for monitoring of foundation pit displacement at different depths or at different heights of the inner wall of the foundation pit, thereby further improving the accuracy of the monitoring operation.

[0011] Optionally, the anti-detachment structure includes a sliding member and a sliding groove adapted to it, wherein the sliding member is disposed on the first connecting post or the second connecting post, and the sliding groove is correspondingly opened on the second connecting post or the first connecting post.

[0012] By adopting the above technical solution, the movement of the sliding member in the sliding groove can cause the first connecting column and the second connecting column to expand or contract with each other. When the sliding member abuts against the inner wall of the sliding groove, it can bring the first connecting column and the second connecting column to the limit position, thereby reducing the occurrence of the first connecting column and the second connecting column separating from each other.

[0013] Optionally, the steering retaining structure includes two sliding seats that are slidably connected to the fixed seat, and the two sliding seats are respectively located on two opposite sides of the second connecting column; The sliding seat has a first toothed portion on its side facing the second connecting column, and the second connecting seat has a second toothed portion on its side that cooperates with and limits the first toothed portion. The fixed base is also equipped with a positioning structure for positioning the sliding base to move.

[0014] By adopting the above technical solution, the sliding seat is positioned by the positioning structure. When the sliding seat is against the second connecting column, the rotation direction of the second connecting column can be maintained by the cooperation and limiting between the first toothed part and the second toothed part. This ensures that the cable and the telescopic component remain perpendicular, so that when the inner wall of the pit is displaced, the sleeve can smoothly force the telescopic component to retract inward under the action of gravity, and monitor the occurrence of pit displacement.

[0015] Optionally, the top surface of the fixed base is provided with a mounting groove, and the positioning structure includes a fixed rod fixedly mounted in the mounting groove and a limiting arm plate rotatably disposed inside the mounting groove. The limiting arm plate has a hook part that cooperates with the fixed rod for positioning. The end of the limiting arm plate is provided with a limiting part. When the hook part cooperates with the fixed rod, the limiting part forces the first toothed part and the second toothed part to cooperate and limit each other.

[0016] By adopting the above technical solution, and by placing the positioning structure on the fixed seat, the construction personnel can easily force the hook part to hook and position with the fixed rod by applying force to the positioning structure with their feet. At this time, the limiting part forces the first toothed part and the second toothed part to cooperate and limit the movement, which can quickly complete the turning positioning of the telescopic component. It has the advantages of simple and quick operation. Furthermore, when there is an angular deviation between the telescopic component and the cable, which affects the accuracy of monitoring, the position of the telescopic component can be easily adjusted, making it highly operable.

[0017] Optionally, the anchoring mechanism anchored to the inner wall of the foundation pit is equipped with a first positioning roller, and the fixed base is equipped with a second positioning roller, with the second positioning roller located below the first positioning roller; the cable is wound around the first and second positioning rollers multiple times and then anchored to the inner wall of the foundation pit through the anchoring mechanism.

[0018] By adopting the above technical solution, the length of the cable can be effectively extended by wrapping the cable multiple times around the first and second positioning rollers before anchoring it to the inner wall of the pit. When the inner wall of the pit shifts, the first positioning roller moves closer to the second positioning roller, and all sections of the cable are in a relaxed state. Under its own gravity, the sleeve forces the telescopic component to naturally contract and then straighten the cable again between the first and second positioning rollers. At this time, the displacement value monitored by the magnetostrictive displacement sensor can be amplified, which can provide a rapid early warning when the inner wall of the pit shifts, further improving the accuracy of the monitoring operation.

[0019] Optionally, the anchoring mechanism anchored to the bottom wall of the pit is rotatably connected to a pressure plate, and an elastic component is provided between the pressure plate and the anchoring mechanism to force the pressure plate to press against the cable and keep the cable taut.

[0020] By adopting the above technical solution, and by setting up elastic components to always generate elastic force acting on the pressure plate, even after the inner wall of the pit shifts and the cable becomes loose, the pressure plate always presses against the cable. This helps to bring the cable wound between the first and second positioning rollers back to a tensioned state, so that the magnetostrictive displacement sensor can successfully monitor the occurrence of pit displacement and ensure the accuracy of the monitoring operation.

[0021] Optionally, the elastic component includes an arc-shaped column and a second spring, the arc-shaped column being fixed to the anchoring mechanism; the arc-shaped column passes through the pressure plate, and the arc axis of the arc-shaped column coincides with the rotation axis of the pressure plate; The arc-shaped column has an end head at the end away from the anchoring mechanism. A second spring is sleeved on the arc-shaped column, with one end of the second spring pressed against the end head and the other end pressed against the pressure plate. The second spring is used to force the pressure plate to flip downward.

[0022] By adopting the above technical solution, the elastic force of the second spring acting on the pressure plate can force the pressure plate to flip downward and press against the cable, which is beneficial to keep the cable in a taut state under normal conditions, so that the magnetostrictive displacement sensor can be successfully monitored when the foundation pit displacement occurs.

[0023] Optionally, the monitoring device is provided in multiple sets, with each set of monitoring devices arranged at intervals on the inner wall of the foundation pit.

[0024] By adopting the above technical solution, multiple sets of monitoring devices can be deployed at intervals on the inner wall of the foundation pit to measure the displacement of the foundation pit at different locations. At the same time, by changing the height of the anchorage between the cable and the inner wall of the foundation pit, the displacement of the entire foundation pit can be effectively monitored to ensure the safety of construction and reduce safety hazards.

[0025] Secondly, the monitoring method provided in this application adopts the following technical solution: A monitoring method includes the following steps: Step S1: Set up multiple foundation pit displacement monitoring points on the inner side wall of the foundation pit, fix a monitoring device at each monitoring point, and automatically monitor the overall foundation pit displacement. Step S2: Fix the telescopic mechanism inside the pit so that the cable passes through the perforation of the sleeve; Step S3: Connect the two ends of the cable to two sets of anchoring mechanisms respectively, and anchor one set of anchoring mechanisms to the bottom wall of the pit; stretch the cable to keep it taut, and then anchor the other set of anchoring mechanisms to the bottom wall of the pit. Step S4: Connect the magnetostrictive displacement sensor to the monitoring information processing unit and calibrate and zero the magnetostrictive displacement sensor to monitor the displacement of the inner wall of the pit.

[0026] By adopting the above technical solution, when the inner wall of the foundation pit is displaced, the cable is in a slack state, and the sleeve moves downward under its own gravity, which can change the monitoring value of the magnetostrictive displacement sensor, and then send a signal to the monitoring information processing unit, so that the signal can be processed and displayed or an alarm can be issued. It has the advantage of rapid response, ensuring that the displacement of the foundation pit sidewall can be detected in time, and effectively improving the accuracy of monitoring operations.

[0027] In summary, this application includes at least one of the following beneficial technical effects: 1. By setting up cables anchored between the inner wall and the bottom wall of the pit, when the inner wall of the pit shifts, the cables will become loose. At this time, the sleeve can force the telescopic component to retract inward under its own weight. The measurement value of the magnetostrictive displacement sensor changes, which can alert the construction personnel to the occurrence of pit displacement. It has the advantages of high accuracy and fast response. 2. By setting a positioning structure to position the sliding seat, when the sliding seat abuts against the second connecting column, the rotation direction of the second connecting column can be maintained by the cooperation and limiting between the first toothed part and the second toothed part, so as to keep the cable and the telescopic component in a perpendicular state and monitor the generation of pit displacement. 3. By winding the cable around the first and second positioning rollers and then anchoring it to the inner wall of the pit, the length of the cable can be effectively extended. This allows the displacement value monitored by the magnetostrictive displacement sensor to be amplified when the inner wall of the pit shifts, enabling rapid early warning when displacement occurs and further improving the accuracy of monitoring operations. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the monitoring device in Example 1; Figure 2 This is a schematic diagram of the telescopic mechanism in Example 1; Figure 3 This is a cross-sectional view of the telescopic component in Embodiment 1, mainly showing the specific structure of the anti-detachment structure; Figure 4 yes Figure 2 Enlarged view of point A in the middle; Figure 5 This is a schematic diagram of the structure in Embodiment 1 when the first toothed part and the second toothed part cooperate to limit the movement and keep the telescopic component at the rotation angle; Figure 6 This is a schematic diagram of the monitoring device installed inside the foundation pit in Example 1; Figure 7 This is a schematic diagram of the overall structure of the monitoring device in Example 2; Figure 8 yes Figure 7 Enlarged view of point B in the middle.

[0029] Explanation of reference numerals in the attached drawings: 1. Cable; 2. Sleeve; 21. Perforation; 3. Telescopic mechanism; 31. Fixed seat; 311. Mounting groove; 32. First connecting post; 33. Second connecting post; 331. Second toothed part; 34. Anti-detachment structure; 341. Sliding part; 342. Sliding groove; 35. Steering and holding structure; 351. Sliding seat; 352. First toothed part; 36. Positioning structure; 37. Fixed rod; 38. Limiting arm plate; 381. Hook connection; 382. Limiting part; 383. Foot pedal; 39. Rotating shaft; 4. Magnetostrictive displacement sensor; 41. Sensor body; 42. Moving magnetic ring; 5. Anchoring mechanism; 51. Anchor seat; 52. Anchor rod; 53. Hook and ring; 54. First anchoring mechanism; 55. Second anchoring mechanism; 6. First positioning roller; 7. Second positioning roller; 8. Pressure plate; 9. Elastic component; 91. Arc-shaped column rod; 911. End head; 92. Second spring. Detailed Implementation

[0030] The following is in conjunction with the appendix Figure 1-8 This application will be described in further detail.

[0031] Example 1 This application discloses a deep foundation pit displacement monitoring device.

[0032] Reference Figure 1 A deep foundation pit displacement monitoring device includes a cable 1, a sleeve 2, a telescopic mechanism 3, and a magnetostrictive displacement sensor 4. Anchoring mechanisms 5 are provided at both ends of the cable 1. One anchoring mechanism 5 is used to anchor the cable 1 to the bottom wall of the foundation pit, and the other anchoring mechanism 5 is used to anchor the cable 1 to the inner side wall of the foundation pit. The anchored cable 1 is taut. Specifically, the anchoring mechanism 5 includes an anchor seat 51 and an anchor rod 52. The side of the anchor seat 51 is integrally formed with a hook 53 for binding the cable 1. When the anchor seat 51 abuts against the inner side wall of the foundation pit, the anchor rod 52 passes through the anchor seat 51 and is anchored to the inner side wall of the foundation pit, thereby firmly fixing the anchor seat 51.

[0033] Reference Figure 2 The telescopic mechanism 3 includes a fixed base 31 and a telescopic assembly. The fixed base 31 is anchored inside the foundation pit. In this embodiment, the anchoring position of the fixed base 31 is located at the corner inside the foundation pit. The telescopic mechanism 3 includes a first connecting column 32 and a second connecting column 33. The second connecting column 33 is slidably sleeved on the first connecting column 32. The second connecting column 33 is rotatably connected to the fixed base 31, and the sleeve 2 is welded and fixed to the end of the first connecting column 32 away from the second connecting column 33. The sleeve 2 is provided with an axially penetrating through hole 21, and refers to... Figure 1 The cable 1 is inserted inside the perforation 21; when the cable 1 is taut, the sleeve 2 can be pulled by the cable 1 so that the first connecting post 32 and the second connecting post 33 can be in the unfolded state.

[0034] Back Figure 2The magnetostrictive displacement sensor 4 includes a sensor body 41 and a movable magnetic ring 42. In this embodiment, the sensor body 41 is fixedly connected to the sleeve 2, and the axial direction of the sensor body 41 is the same as the length direction of the telescopic assembly. The movable magnetic ring 42 is fixedly connected to the second connecting post 33 of the telescopic assembly, and the movable magnetic ring 42 is always slidably sleeved on the sensor body 41 and does not directly contact the sensor body 41. This enables the magnetostrictive displacement sensor 4 to maintain a good mechanical life and reduces the frequency of maintenance and replacement of the magnetostrictive displacement sensor 4.

[0035] Back Figure 1 When the inner wall of the foundation pit is displaced, the cable 1 becomes slack, and the sleeve 2 can force the telescopic component to retract naturally under its own gravity. At this time, the moving magnetic ring 42 moves along the axis of the sensor body 41, and the measurement value of the magnetostrictive displacement sensor 4 changes, so as to successfully monitor the occurrence of displacement of the inner wall of the foundation pit.

[0036] It should also be noted that in another feasible embodiment, the sensor body 41 can also be fixedly connected to the second connecting post 33 of the telescopic component, and the movable magnetic ring 42 is correspondingly fixed to the sleeve 2, so that the movable magnetic ring 42 slides and is sleeved on the sensor body 41, which can also successfully monitor the occurrence of displacement of the inner sidewall of the foundation pit, and is not limited to the method provided in this embodiment.

[0037] Reference Figure 3 An anti-detachment structure 34 is provided between the first connecting post 32 and the second connecting post 33 to prevent the first connecting post 32 and the second connecting post 33 from detaching from each other. The anti-detachment structure 34 includes a sliding member 341 and a sliding groove 342 adapted to slide therethrough. In this embodiment, the sliding member 341 is fixed to the outer peripheral surface of the first connecting post 32, while the sliding groove 342 is opened on the inner peripheral surface of the second connecting post 33. When the sliding member 341 moves in the sliding groove 342, it can abut against the two end walls of the sliding groove 342, thereby keeping the first connecting post 32 and the second connecting post 33 in a sliding fit.

[0038] It should also be noted that, in another feasible embodiment, the sliding member 341 can also be fixed to the inner circumferential surface of the second connecting post 33, and the sliding groove 342 is correspondingly opened on the outer circumferential surface of the first connecting post 32, which can also enable the first connecting post 32 and the second connecting post 33 to maintain a sliding fit, and is not limited to the method provided in this embodiment.

[0039] Reference Figure 4A steering retaining structure 35 is provided between the second connecting post 33 and the fixed base 31 to position the rotation angle between the telescopic component and the fixed base 31. The steering retaining structure 35 includes two sliding seats 351, each sliding seat 351 being slidably connected to the fixed base 31, and the two sliding seats 351 being located on two opposite sides of the second connecting post 33. In addition, a first toothed portion 352 is integrally formed on the side of the sliding seat 351 facing the second connecting post 33, and a second toothed portion 331 is integrally formed on the side of the second connecting post 33. When the sliding seat 351 abuts against the second connecting post 33, the rotation of the second connecting post 33 can be restricted through the cooperation between the first toothed portion 352 and the second toothed portion 331, so that the rotation angle between the second connecting post 33 and the fixed base 31 can be maintained.

[0040] In addition, the top surface of the fixed base 31 is provided with a mounting groove 311, and a positioning structure 36 for positioning the moving position of the sliding seat 351 is provided in the mounting groove 311. The positioning structure 36 in this embodiment includes a fixing rod 37 and a limiting arm plate 38. The fixing rod 37 is fixedly mounted in the mounting groove 311, and the axis of the fixing rod 37 is horizontal. There are two limiting arm plates 38, which are used to control the two sliding seats 351 respectively. A rotating shaft 39 is fixedly connected between the two limiting arm plates 38. The two limiting arm plates 38 can be rotated together in the mounting groove 311 through the rotating shaft 39, and the two limiting arm plates 38 can rotate simultaneously.

[0041] The limiting arm plate 38 has an integrally formed hook part 381 in the middle. By rotating the limiting arm plate 38, the hook part 381 is engaged with the fixing rod 37 for positioning, thus maintaining the position of the limiting arm plate 38. One end of the limiting arm plate 38 has an integrally formed limiting part 382. The limiting part 382 has a guide surface facing the side of the other limiting arm plate 38. When the limiting arm plate 38 rotates, the limiting part 382 can abut against the side of the sliding seat 351. At this time, the guide surface guides the sliding seat 351, automatically forcing the sliding seat 351 to move closer to the second connecting post 33. Finally, the limiting part 382 can abut against the side of the sliding seat 351 away from the second connecting post 33, and then the rotation angle of the second connecting post 33 is positioned by the engagement of the first toothed part 352 and the second toothed part 331.

[0042] In addition, a foot pedal 383 is provided at the other end of the limiting arm plate 38. The foot pedal 383 and the limiting part 382 are located at the two ends of the limiting arm plate 38, respectively. The foot pedal 383 is normally exposed on the top surface of the fixed seat 31, so that the construction personnel can step on the foot pedal 383 to control the rotation of the limiting arm plate 38 and hook the hook connection 381 to the fixed rod 37 for positioning. This helps to improve the convenience of operation for construction personnel and reduce labor intensity.

[0043] See also Figure 6 The monitoring device of this application consists of multiple sets, all of which are arranged at intervals along the inner wall of the foundation pit, specifically within a range of 30-40 meters, to monitor the displacement of the entire deep foundation pit's sidewalls in real time. Furthermore, by changing the anchorage height between the cable 1 and the inner wall of the foundation pit, the displacement of the entire foundation pit can be further detected to ensure construction safety and reduce potential safety hazards. Each set of monitoring devices' magnetostrictive displacement sensors 4 is electrically connected to the back-end monitoring information processing unit, enabling the transmission of measured numerical signals to the unit for unified processing, display, or alarm issuance to alert construction personnel to the occurrence of foundation pit displacement phenomena.

[0044] The implementation principle of a deep foundation pit displacement monitoring device according to an embodiment of this application is as follows: After the cable 1 is threaded through the sleeve 2 and kept taut, the magnetostrictive displacement sensor 4 is calibrated and zeroed to measure the displacement value of the inner wall of the foundation pit. When the inner wall of the foundation pit shifts, the cable 1 becomes slack, and the sleeve 2, under its own weight, forces the telescopic component to retract inward, causing relative displacement between the moving magnetic ring 42 and the sensor body 41. At this time, the measured value of the magnetostrictive displacement sensor 4 changes, and the numerical information is sent to the monitoring information processing unit for display or alarm to alert construction personnel of the occurrence of foundation pit displacement. It has the advantages of high accuracy and fast response, ensuring that the displacement of the foundation pit sidewall can be detected in a timely manner.

[0045] Example 2 This application discloses a deep foundation pit displacement monitoring device.

[0046] Reference Figure 7 This application discloses a deep foundation pit displacement monitoring device. The remaining components are the same as in Embodiment 1, and will not be described in detail here. The difference from Embodiment 1 is that the monitoring device in this embodiment further includes a first positioning roller 6 and a second positioning roller 7. The anchoring mechanism 5 anchored to the inner wall of the foundation pit is set as a first anchoring mechanism 54, and the first positioning roller 6 is mounted on the first anchoring mechanism 54. The second positioning roller 7 is mounted on a fixed base 31, and the second positioning roller 7 is located below the first positioning roller 6. When installing the cable 1, the cable 1 is first wound around the first positioning roller 6 and the second positioning roller 7 multiple times, and then hooked and fixed with the hook 53 of the first anchoring mechanism 54, so that the cable 1 is anchored between the inner wall and the bottom wall of the foundation pit and remains taut.

[0047] Additionally, refer to Figure 8The anchoring mechanism 5, which is anchored to the bottom wall of the pit, is set as the second anchoring mechanism 55. The second anchoring mechanism 55 is rotatably connected to the pressure plate 8. After the cable 1 passes through the area between the pressure plate and the anchor seat 51, it is fixed to the hook 53 of the second anchoring mechanism 55. An elastic component 9 is provided between the pressure plate 8 and the second anchoring mechanism 55. The elastic component 9 can always generate an elastic force acting on the pressure plate 8, thereby forcing the pressure plate 8 to press against the cable 1, so that the cable 1 remains taut.

[0048] The elastic component 9 includes an arc-shaped column 91 and a second spring 92. The arc-shaped column 91 is fixed to the anchor seat 51 of the second anchoring mechanism 55, and the arc axis of the arc-shaped column 91 coincides with the rotation axis of the abutment plate. The pressure plate 8 has an insertion hole, and the arc-shaped column 91 passes through the insertion hole, allowing the pressure plate 8 to rotate freely along the arc-shaped column 91. The end of the arc-shaped column 91 away from the connected anchor seat 51 has an integrally formed end head 911, the outer diameter of which is larger than the outer diameter of the arc-shaped column 91. The second spring 92 is sleeved on the arc-shaped column 91, one end of which abuts against the end head 911, and the other end of which abuts against the pressure plate 8. The second spring 92 can always generate an elastic force acting on the pressure plate 8, thereby forcing the pressure plate 8 to rotate downward and press the cable 1, keeping the cable 1 taut.

[0049] The implementation principle of a deep foundation pit displacement monitoring device according to an embodiment of this application is as follows: By winding the cable 1 multiple times around the first positioning roller 6 and the second positioning roller 7 before anchoring it to the inner wall of the pit, the length of the cable 1 can be effectively extended. After the inner wall of the pit shifts, the first positioning roller 6 moves closer to the second positioning roller 7, and each winding section of the cable 1 is in a relaxed state. Under its own gravity, the sleeve 2 forces the telescopic component to naturally contract and then straighten the cable 1 between the first positioning roller 6 and the second positioning roller 7. The displacement value monitored by the magnetostrictive displacement sensor 4 can be amplified, which can provide a rapid early warning when the inner wall of the pit shifts, further improving the accuracy of the monitoring operation.

[0050] Example 3 This application also discloses a monitoring method.

[0051] A monitoring method, based on the deep foundation pit displacement monitoring device in Example 1, specifically includes the following steps: Step S1: Set up multiple foundation pit displacement monitoring points on the inner sidewall of the foundation pit, with the distance between adjacent foundation pit displacement monitoring points being within 30-40 meters; fix a monitoring device on each monitoring point to automatically monitor the overall foundation pit displacement.

[0052] Step S2: Fix the fixed seat 31 of the telescopic mechanism 3 to the corner position inside the pit, so that the cable 1 passes through the through hole 21 of the sleeve 2.

[0053] Step S3: Hook the two ends of the cable 1 to the hooks 53 of the two sets of anchoring mechanisms 5 respectively, place the anchor seat 51 of one set of anchoring mechanisms 5 against the bottom wall of the pit, and anchor the anchor seat 51 to the bottom wall of the pit through the anchor rod 52; stretch the cable 1 to keep it taut, and then place the anchor seat 51 of the other set of anchoring mechanisms 5 against the inner wall of the pit, and anchor the anchor seat 51 to the inner wall of the pit through the anchor rod 52.

[0054] Step S4: Connect the magnetostrictive displacement sensor 4 to the monitoring information processing unit, and calibrate and zero the magnetostrictive displacement sensor 4 to monitor the displacement of the inner wall of the pit.

[0055] Example 4 This application also discloses a monitoring method.

[0056] A monitoring method based on the deep foundation pit displacement monitoring device in Example 2, differs from Example 3 in step S3.

[0057] Step S3: Connect one end of the cable 1 to the hook 53 of a set of anchoring mechanisms 5, and fix the anchor seat 51 to the bottom wall of the pit through the anchor rod 52; wrap the free end of the cable 1 around the first positioning roller 6 and the second positioning roller 7 multiple times, and then connect the cable 1 to the hook 53 of another set of anchoring mechanisms 5, and press the anchor seat 51 of the set of anchoring mechanisms 5 against the inner wall of the pit, and anchor the anchor seat 51 to the inner wall of the pit through the anchor rod 52.

[0058] The above are preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A deep foundation pit displacement monitoring device, characterized in that: The cable (1), sleeve (2), telescopic mechanism (3) and magnetostrictive displacement sensor (4) are included. Anchoring mechanisms (5) are provided at both ends of the cable (1). The cable (1) is anchored between the inner side wall and the bottom wall of the pit through the anchoring mechanism (5), and the cable (1) is in a taut state. The telescopic mechanism (3) includes a fixed seat (31) and a telescopic component connected thereto. The fixed seat (31) is fixed inside the pit, and the sleeve (2) is fixed at the end of the telescopic component away from the fixed seat (31). The sleeve (2) is provided with an axially penetrating hole (21), and the cable (1) passes through the hole (21). The magnetostrictive displacement sensor (4) includes a sensor body (41) and a movable magnetic ring (42) that cooperates with it. The sensor body (41) is installed on the sleeve (2) or the telescopic assembly, and the movable magnetic ring (42) is installed on the telescopic assembly or the sleeve (2).

2. The deep foundation pit displacement monitoring device according to claim 1, characterized in that: The telescopic assembly includes a first connecting post (32) and a second connecting post (33) that are nested together, and an anti-detachment structure (34) is provided between the first connecting post (32) and the second connecting post (33). The first connecting post (32) is connected to the sleeve (2), and the second connecting post (33) is rotatably connected to the fixed base (31); the sensor body (41) is installed on the sleeve (2) or the second connecting post (33), and the movable magnetic ring (42) is correspondingly installed on the second connecting post (33) or the sleeve (2). A steering retaining structure (35) is provided between the second connecting column (33) and the fixed seat (31) for positioning the rotation angle between the telescopic component and the fixed seat (31).

3. The deep foundation pit displacement monitoring device according to claim 2, characterized in that: The anti-detachment structure (34) includes a sliding member (341) and a sliding groove (342) adapted to slide therethrough. The sliding member (341) is disposed on the first connecting post (32) or the second connecting post (33), and the sliding groove (342) is correspondingly opened on the second connecting post (33) or the first connecting post (32).

4. The deep foundation pit displacement monitoring device according to claim 2, characterized in that: The steering holding structure (35) includes two sliding seats (351) slidably connected to the fixed seat (31), and the two sliding seats (351) are respectively located on two opposite sides of the second connecting column (33); The sliding seat (351) has a first toothed portion (352) on the side facing the second connecting post (33), and the side of the second connecting seat has a second toothed portion (331) that cooperates with and limits the first toothed portion (352). The fixed base (31) is also provided with a positioning structure (36) for positioning the moving position of the sliding base (351).

5. The deep foundation pit displacement monitoring device according to claim 4, characterized in that: The top surface of the fixed base (31) is provided with an installation groove (311), and the positioning structure (36) includes a fixed rod (37) fixedly mounted on the installation groove (311) and a limiting arm plate (38) rotatably disposed inside the installation groove (311). The limiting arm plate (38) has a hook part (381) that cooperates with the fixed rod (37) for positioning. The end of the limiting arm plate (38) is provided with a limiting part (382). When the hook part (381) cooperates with the fixed rod (37), the limiting part (382) forces the first toothed part (352) and the second toothed part (331) to cooperate and limit each other.

6. The deep foundation pit displacement monitoring device according to claim 1, characterized in that: The anchoring mechanism (5) anchored to the inner wall of the foundation pit is provided with a first positioning roller (6), and the fixed seat (31) is provided with a second positioning roller (7). The second positioning roller (7) is located below the first positioning roller (6). The cable (1) is wound around the first positioning roller (6) and the second positioning roller (7) and then anchored to the inner wall of the foundation pit through the anchoring mechanism (5).

7. The deep foundation pit displacement monitoring device according to claim 6, characterized in that: The anchoring mechanism (5) anchored to the bottom wall of the pit is rotatably connected to a pressure plate (8). An elastic component (9) is provided between the pressure plate (8) and the anchoring mechanism (5) to force the pressure plate (8) to press against the cable (1) and keep the cable (1) taut.

8. The deep foundation pit displacement monitoring device according to claim 7, characterized in that: The elastic component (9) includes an arc-shaped column (91) and a second spring (92). The arc-shaped column (91) is fixed to the anchoring mechanism (5). The arc-shaped column (91) passes through the pressure plate (8), and the arc axis of the arc-shaped column (91) coincides with the rotation axis of the pressure plate. The arc-shaped column (91) has an end head (911) at one end away from the anchoring mechanism (5). The second spring (92) is sleeved on the arc-shaped column (91). One end of the second spring (92) abuts against the end head (911), and the other end abuts against the pressure plate (8). The second spring (92) is used to force the pressure plate (8) to flip downward.

9. The deep foundation pit displacement monitoring device according to claim 1, characterized in that: The monitoring device is provided in multiple groups, and each group of monitoring devices is arranged at intervals on the inner wall of the foundation pit.

10. A monitoring method, based on the deep foundation pit displacement monitoring device according to any one of claims 1-9, characterized in that, Includes the following steps: Step S1: Set up multiple foundation pit displacement monitoring points on the inner side wall of the foundation pit, fix a monitoring device at each monitoring point, and automatically monitor the overall foundation pit displacement. Step S2, fix the telescopic mechanism (3) inside the pit so that the cable (1) passes through the hole (21) of the sleeve (2). Step S3: Connect the two ends of the cable (1) to two sets of anchoring mechanisms (5) respectively, and anchor one set of anchoring mechanisms (5) to the bottom wall of the pit; stretch the cable (1) to keep it taut, and then anchor the other set of anchoring mechanisms (5) to the bottom wall of the pit. Step S4: Connect the magnetostrictive displacement sensor (4) to the monitoring information processing unit and calibrate and zero the magnetostrictive displacement sensor (4) to monitor the displacement of the inner wall of the pit.

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