A foundation pit deformation monitoring device

Abstract

The application discloses a kind of foundation pit deformation monitoring equipment, including fixed plate and mounting plate, the fixed plate and mounting plate cooperate anchor rod support structure cooperation use, the fixed plate one side is fixedly arranged with measuring tube, the measuring tube inside is fixedly arranged with telescopic mechanism, the telescopic mechanism one side upper end is fixedly connected with transmission rod, the measuring tube inside upper end is fixedly arranged with measuring mechanism, the measuring mechanism lower end is slidably arranged with one electrically-conductive slider.The application carries out real-time monitoring to the deformation of soil body by two measuring tubes and the mechanism connected therewith, according to the ratio of the difference between the deformation amounts of different positions and the spacing therebetween, combined with the deformation amount of soil body at close range of fixed tube measured, the deformation degree of soil body and the supporting effect of supporting structure are comprehensively evaluated, and the deformed soil body is conveniently reinforced again according to the evaluation result.

Description

A foundation pit deformation monitoring device Technical Field

[0001] This invention belongs to the field of engineering monitoring technology, and specifically relates to a foundation pit deformation monitoring device. Background Technology

[0002] With the continuous construction and development of cities, more and more deep foundation pit projects have emerged. In the construction of deep foundation pit projects, the excavation of soil is a process in which soil is continuously removed from the construction area, and the soil pressure inside the deep foundation pit continuously decreases. Due to the stress release caused by soil excavation, the surrounding soil shifts laterally and the deep foundation pit deforms, eventually reaching a new stress equilibrium. Soil deformation during construction can affect the foundation pit retaining structure and surrounding buildings and facilities, and in severe cases, can affect the normal use of the structure, easily causing casualties and financial losses. For example, subway pipelines located below the side of the excavated foundation pit will exhibit an upward inclined movement trend. Therefore, foundation pit deformation monitoring devices are typically used to continuously and actively monitor the deformation of the foundation pit, and the construction plan is adjusted based on the real-time monitoring results.

[0003] Typically, foundation pit deformation monitoring devices include a sliding mechanism to reflect soil deformation and displacement, and a laser rangefinder to measure the displacement. In use, the device is installed on the deformed surface. Soil deformation causes a sliding block within the sliding mechanism to slide, and the laser rangefinder measures the displacement. However, traditional foundation pit deformation monitoring devices usually monitor the soil and the supporting structure of the retaining soil separately. Due to differences in measurement accuracy and relative measurement positions, the data results have low integration, making it difficult to fully utilize the measured data to evaluate the effectiveness of the support and the degree of deformation when the data volume is small. Summary of the Invention

[0004] In view of the shortcomings of existing foundation pit deformation monitoring devices mentioned in the background art, the present invention provides a foundation pit deformation monitoring device, which has the advantages of making full use of monitoring data and real-time monitoring, and solves the technical problems mentioned in the background art.

[0005] This invention provides the following technical solution: a foundation pit deformation monitoring device, comprising a fixed plate and an mounting plate, the fixed plate and the mounting plate being used in conjunction with an anchor bolt support structure, a measuring tube being fixedly installed on one side of the fixed plate, a telescopic mechanism being fixedly installed inside the measuring tube, a transmission rod being fixedly connected to the upper end of one side of the telescopic mechanism, a measuring mechanism being fixedly installed at the upper end of the inner side of the measuring tube, a conductive slider being slidably installed at the lower end of the measuring mechanism, and a current sensor being fixedly installed on one side inside the measuring tube.

[0006] A fixing tube is fixedly connected to one side of the mounting plate. A second resistance rod is fixedly connected to one side of the inner wall of the fixing tube. A second conductive block is fixedly connected to the other end of the second resistance rod. A second conductive slider is slidably sleeved on the body of the second resistance rod. A fixing rod is fixedly connected to the upper end of the second conductive slider. Equal voltages are applied to both ends of the second conductive slider and the second conductive block. A second current sensor is fixedly installed inside one side of the fixing tube.

[0007] Furthermore, a connector is fixedly connected to the lower end of the fixing plate, and the connector is fixedly installed on the slide plate by bolts. The slide plate is sleeved on the outside of the anchor rod and fixed by nuts. A No. 1 battery is fixedly installed on one side inside the measuring tube, and there are two measuring tubes.

[0008] Furthermore, the telescopic mechanism includes a limiting plate, the lower end of which is fixedly connected to the inner wall of the measuring tube. A spring is fixedly connected to one side of the limiting plate, and a sliding plate is fixedly connected to the other end of the spring. A connecting rod is fixedly connected to the midpoint of the other side of the sliding plate. The upper end of one side of the sliding plate is fixedly connected to a transmission rod, and a first contact plate is fixedly connected to the other end of the connecting rod.

[0009] Furthermore, the measuring mechanism includes two No. 1 fixing blocks, the upper ends of the two No. 1 fixing blocks are fixedly connected to the inner wall of the measuring tube, a No. 1 resistance rod is fixedly connected to one side of the two No. 1 fixing blocks, and a No. 1 conductive block is fixedly connected to one end of the No. 1 resistance rod. A contact switch is fixedly installed on the side of the No. 1 conductive block closer to the No. 1 fixing block. The outer side of the No. 1 resistance rod is slidably sleeved with the No. 1 conductive slider.

[0010] Furthermore, the mounting plate is fixedly installed on the outside of the soil by positioning pins, the mounting plate is close to the drag plate, and a No. 2 battery is fixedly installed on one side of the inside of the fixing tube.

[0011] Furthermore, two electric push rods are fixedly installed on one side of the fixed plate, and baffles are fixedly connected to the output ends of the two electric push rods. The first conductive slider is fixedly connected to the transmission rod.

[0012] Furthermore, the anchor bolt includes a free section and an anchoring section. The free section is located outside the soil, and the anchoring section is located inside the soil. A fixing rod is fixedly connected to the lower end of the free section. Beneficial Effects

[0013] 1. This invention uses a telescopic mechanism to move a transmission rod, causing the first conductive sliding block to slide relative to the first resistance rod. By changing the length of the first resistance rod connected to the circuit, the current changes. The deformation of the soil is monitored in real time based on the change in current. By calculating the ratio of the difference in deformation measured by the two measuring tubes to the distance between them, and combining this with the amount of relative sliding of the second conductive slider in the fixed tube relative to the second resistance rod, the deformation of the soil within the anchor support structure can be evaluated even with a small amount of data. This is helpful in determining whether the anchoring of the support structure is effective and facilitates secondary reinforcement of the deformed soil based on the monitoring results.

[0014] 2. The present invention connects the contact switch in the measuring mechanism to two electric push rods. When the soil undergoes significant deformation, the first conductive slider contacts the contact switch, the two electric push rods start and push the baffle to press against the soil, and the fixing plate is installed on the slide plate through the connector, so that the device will not lose its temporary support function due to the fixing point collapsing with the soil deformation because it is fixed to the soil. Attached Figure Description

[0015] Figure 1 is a schematic diagram of the structure of the present invention;

[0016] Figure 2 is a partial structural schematic diagram of the present invention as shown in Figure 1;

[0017] Figure 3 is a partial cross-sectional view of the structure of the present invention shown in Figure 1;

[0018] Figure 4 is a schematic cross-sectional view of the measuring tube structure of the present invention as shown in Figure 1.

[0019] In the diagram: 1. Fixed plate; 2. Measuring tube; 3. Telescopic mechanism; 301. Contact plate; 302. Connecting rod; 303. Sliding plate; 304. Spring; 305. Limiting plate; 4. Measuring mechanism; 401. Fixed block No. 1; 402. Resistance rod No. 1; 403. Contact switch; 404. Conductive block No. 1; 5. Conductive slider No. 1; 6. Transmission rod; 7. Mounting plate; 8. Positioning pin; 9. Anchor rod; 901. Free section; 902. Anchoring section; 10. Fixed rod; 11. Fixed tube; 12. Conductive block No. 2; 13. Resistance rod No. 2; 14. Conductive slider No. 2; 15. Battery No. 2; 16. Current sensor No. 2; 17. Baffle; 18. Connector; 19. Slide plate; 20. Battery No. 1; 21. Current sensor No. 1; 22. Electric push rod. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please refer to Figures 1-3. A foundation pit deformation monitoring device includes a fixed plate 1 and a mounting plate 7. A connector 18 is fixedly connected to the lower end of the fixed plate 1. The connector 18 is fixedly mounted on the sliding plate 19 by bolts. A measuring tube 2 is fixedly installed on one side of the fixed plate 1. A first current sensor 21 is fixedly installed on one side inside the measuring tube 2. A first battery 20 is fixedly installed on one side inside the measuring tube 2. The first battery 20 is used to supply power to the current sensor 21 and the detection component inside the measuring tube 2. A telescopic mechanism 3 is fixedly installed inside the measuring tube 2. A transmission rod 6 is fixedly connected to the upper end of one side of the telescopic mechanism 3. The telescopic mechanism 3 includes a limiting plate 305. The lower end of the limiting plate 305 is fixedly connected to the inner wall of the measuring tube 2. A spring 304 is fixedly connected to one side of the limiting plate 305. A sliding plate 303 is fixedly connected to the other end of the spring 304. A connecting rod 302 is fixedly connected to the midpoint of the other side of the sliding plate 303. The upper end of one side of the sliding plate 303 is fixedly connected to the transmission rod 6. A contact plate 301 is fixedly connected to the other end of the connecting rod 302.

[0022] Two electric push rods 22 are fixedly installed on one side of the fixed plate 1. The output ends of the two electric push rods 22 are fixedly connected to baffles 17. The baffles 17 are movably sleeved on the outside of the measuring tube 2 and can slide relative to the measuring tube 2. A measuring mechanism 4 is fixedly installed on the upper end of the inner side of the measuring tube 2. A first conductive slider 5 is slidably installed on the lower end of the measuring mechanism 4. The first conductive slider 5 is fixedly connected to the transmission rod 6. The measuring mechanism 4 includes two first fixing blocks 401. The upper ends of the two first fixing blocks 401 are fixedly connected to the inner wall of the measuring tube 2. A first resistance rod 402 is fixedly connected to one side of the two first fixing blocks 401. A first conductive block 404 is fixedly connected to one end of the first resistance rod 402. A contact switch 403 is fixedly installed on one side of the first conductive block 404 near the first conductive block 404. The outer side of the first resistance rod 402 is slidably sleeved with the first conductive slider 5. There are two measuring tubes 2 and the distance between the two measuring tubes 2 is M.

[0023] When spring 304 is compressed, after the device is installed, contact plate 301 contacts and adheres to the soil surface. The deformation of the soil relative to fixed plate 1 will push contact plate 301 to move, which in turn drives connecting rod 302 to slide, causing sliding plate 303 to slide. Sliding plate 303 drives transmission rod 6 to move, and transmission rod 6 drives conductive slider 5 to slide relative to resistor rod 402. Resistivity of resistor rod 402 is ρ, and cross-sectional area is S. Conductive block 404, conductive slider 5, current sensor 21 and battery 20 are electrically connected. Let L be the length of the resistance between conductive slider 5 and conductive block 404. From the circuit resistance R=ρ·L / S, it can be seen that L and R are directly proportional.

[0024] Since the voltage U across the first conductive slider 5 and the first conductive block 404 remains constant, it can be deduced that the current measured by the first current sensor 21 across the first conductive slider 5 and the first conductive block 404 is inversely proportional to the distance between them, specifically I = U·S / (ρ·L). The operator can obtain the value of L at the measurement moment based on the current. The fixed plate 1 moves with the sliding plate 19, similarly causing the first resistance rod 402 to slide relative to the first conductive slider 5. Let the initial current be I1, and the measured current... Let I2 be the initial time L, N1 be the initial time L, and N2 be the measurement time L. We can obtain I1 = U·S / (ρ·N1) and I2 = U·S / (ρ·N2). Then, the displacement of the contact plate 301 relative to the fixed plate 1 is S1 = N1 - N2 = U·S(I1 - I2) / (I1·I2·ρ). The contact switch 403 is electrically connected to the two electric push rods 22. When the first conductive slider 5 slides to contact the contact switch 403, the two electric push rods 22 are activated, pushing the baffle 17 against the soil for temporary support.

[0025] Referring to Figure 4, the drag plate 19 is sleeved on the outside of the anchor rod 9 and fixed with a nut. The anchor rod 9 includes a free section 901 and an anchoring section 902. The free section 901 is located on the outside of the soil, and the anchoring section 902 is located inside the soil. A fixing rod 10 is fixedly connected to the lower end of the free section 901. A second conductive slider 14 is fixedly connected to the lower end of the fixing rod 10. The mounting plate 7 is fixedly installed on the outside of the soil by a positioning pin 8. The mounting plate 7 is close to the drag plate 19. A fixing tube 11 is fixedly connected to one side of the mounting plate 7. A second battery 15 is fixedly installed on one side inside the fixing tube 11. A second current sensor 16 is fixedly installed on one side inside the fixing tube 11. A second resistance rod 13 is fixedly connected to one side of the inner wall of the fixing tube 11. A second conductive block 12 is fixedly connected to the other end of the second resistance rod 13. The second resistance rod 13 and the second conductive slider 14 are slidably sleeved together.

[0026] The second conductive slider 14, the second conductive block 12, the second current sensor 16, and the second battery 15 are electrically connected. The voltage U across the second conductive slider 14 and the second conductive block 12 remains constant. The length of the second resistor rod 13 between them is L, the resistivity is ρ, and the cross-sectional area is S. Let the current through the second resistor rod 13 at the initial moment be I3, and the current at the measurement moment be I4. Let L at the initial moment be N3 and L at the measurement moment be N4. We can obtain I3 = U·S / (ρ·N3) and I4 = U·S / (ρ·N4). Then, the displacement S2 of the second conductive slider 14 relative to the second resistor rod 13 is S2 = N3 - N4 = U·S(I3 - I2) / (I3·I4·ρ). The changes in the relative position of the second conductive slider 14 relative to the second resistor rod 13 can be in the following ways.

[0027] The position of the second conductive slider 14 relative to the second resistance rod 13 does not change, i.e., S2=0. At this time, the displacement S1 of the contact plate 301 corresponding to the two measuring tubes 2 relative to the fixed plate 1 is recorded as M1 and M2 respectively. The safe deformation degree A is set as (M1-M2) / M×100%. A is calculated. If A is lower than the rated value, the anchoring effect of the anchor rod 9 is good, and the soil at the mounting plate 7 and the drag plate 19 does not deform. Conversely, if A is higher than the rated value, it means that the soil at the mounting plate 7 and the drag plate 19 deforms and the deformation amount is the same. At this time, the soil may deform in a large range, and secondary reinforcement measures should be taken.

[0028] When the position of the second conductive slider 14 relative to the second resistance rod 13 changes (i.e., S2≠0), the soil at the mounting plate 7 and the drag plate 19 deforms, and the deformation amounts are inconsistent. This causes the fixed rod 10, which is fixedly connected to the free section 901, to move relative to the fixed pipe 11, causing the second conductive slider 14 to slide relative to the second resistance rod 13. At this time, the anchoring effect of the anchor rod 9 fails, and secondary reinforcement measures should be taken.

[0029] The method of use (working principle) of this invention is as follows: The fixing plate 1 is installed on the sliding plate 19 through the connector 18. The contact plates 301 of the two measuring tubes 2 are pressed against the soil. The mounting plate 7 is installed on the soil near the sliding plate 19 through the positioning pin 8. The fixing rod 10 is fixed to the free section 901 of the anchor rod 9. At this time, the current in the two measuring tubes 2 and the fixing tube 11 is recorded. When the soil deforms, the soil pushes the contact plate 301 to move, so that the first conductive slider 5 slides relative to the first resistance rod 402. The first current sensor 21 measures the current passing through the first resistance rod 402 at this time and calculates the amount of soil deformation at the measuring tube 2. At the same time, based on the amount of relative sliding of the second conductive slider 14 relative to the second conductive block 12, and combined with the ratio of the deformation measured by the two measuring tubes 2 to the distance between them, it is determined whether the anchor rod 9 has failed.

Claims

1. A foundation pit deformation monitoring device, comprising a fixing plate (1) and an mounting plate (7), wherein the fixing plate (1) and the mounting plate (7) are used in conjunction with an anchor bolt (9) support structure, characterized in that: A measuring tube (2) is fixedly installed on one side of the fixed plate (1). A telescopic mechanism (3) is fixedly installed inside the measuring tube (2). A transmission rod (6) is fixedly connected to the upper end of one side of the telescopic mechanism (3). A measuring mechanism (4) is fixedly installed at the upper end of the inner side of the measuring tube (2). A first conductive slider (5) is slidably installed at the lower end of the measuring mechanism (4). A first current sensor (21) is fixedly installed on one side inside the measuring tube (2). A fixed tube (11) is fixedly connected to one side of the mounting plate (7). A second resistance rod (13) is fixedly connected to one side of the inner wall of the fixed tube (11). A second conductive block (12) is fixedly connected to the other end of the second resistance rod (13). The second resistance rod (13) has a rod body... A second conductive slider (14) is slidably connected to a fixed rod (10) at the upper end of the second conductive slider (14). Equal voltages are applied to both ends of the second conductive slider (14) and the second conductive block (12). A second current sensor (16) is fixedly installed on one side inside the fixed tube (11). A connector (18) is fixedly connected to the lower end of the fixed plate (1). The connector (18) is fixedly installed on the slide plate (19) by bolts. The slide plate (19) is sleeved on the outside of the anchor rod (9) and fixed by nuts. A first battery (20) is fixedly installed on one side inside the measuring tube (2). There are two measuring tubes (2). The telescopic mechanism (3) includes a limiting plate (305). 05) The lower end is fixedly connected to the inner wall of the measuring tube (2). A spring (304) is fixedly connected to one side of the limiting plate (305). A sliding plate (303) is fixedly connected to the other end of the spring (304). A connecting rod (302) is fixedly connected to the midpoint of one side of the sliding plate (303). The upper end of the other side of the sliding plate (303) is fixedly connected to the transmission rod (6). One end of the connecting rod (302) is fixedly connected to a first contact plate (301). The measuring mechanism (4) includes two first fixing blocks (401). The upper ends of the two first fixing blocks (401) are fixedly connected to the inner wall of the measuring tube (2). A first resistance rod (402) is fixedly connected to the opposite side of the two first fixing blocks (401). One end of the first resistance rod (402) is fixedly connected to the first conductive block (404). The outer side of the first resistance rod (402) is slidably sleeved with the first conductive slider (5). A second battery (15) is fixedly installed on one side inside the fixed tube (11). The first conductive slider (5) is fixedly connected to the transmission rod (6). The anchor rod (9) includes a free section (901) and an anchoring section (902). The free section (901) is located outside the soil, and the anchoring section (902) is located inside the soil. The fixed rod (10) is fixedly connected to the lower end of the free section (901). The first conductive block (404), the first conductive slider (5), the first current sensor (21), and the first battery (20) are electrically connected.The second conductive slider (14), the second conductive block (12), the second current sensor (16), and the second battery (15) are electrically connected.

2. The foundation pit deformation monitoring device according to claim 1, characterized in that: A contact switch (403) is fixedly installed on one side of the first fixed block (401) which is closer to the first conductive block (404).

3. The foundation pit deformation monitoring device according to claim 1, characterized in that: The mounting plate (7) is fixedly installed on the outside of the soil by positioning pins (8), and the mounting plate (7) is close to the drag plate (19).

4. The foundation pit deformation monitoring device according to claim 1, characterized in that: Two electric push rods (22) are fixedly installed on one side of the fixed plate (1), and baffles (17) are fixedly connected to the output ends of the two electric push rods (22).

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