Waterproof curtain-metro structure surrounding rock seepage pressure stress coordination monitoring device and method

Abstract

The present application belongs to the technical field of water-blocking curtain monitoring, and particularly relates to a water-blocking curtain-metro structure surrounding rock seepage pressure stress cooperative monitoring device and method. The device comprises two groups of first optical fibers arranged on the side close to the high water level of the two water-blocking curtains, and the number of the first optical fibers in each group is eight. The first optical fibers are embedded in the adjacent mixing piles on the side close to the high water level. The side close to the low water level of the mixing piles is provided with eight first stress sensors distributed at equal intervals. The chamber is provided with two groups of second optical fibers and two groups of second stress sensors symmetrically distributed. The present application improves the accuracy of the data during the specific construction by detecting the experimental data in advance. The first optical fibers, the first stress sensors, the second optical fibers and the second stress sensors cooperatively monitor the water-blocking curtain and the adjacent chamber surrounding rock under the seepage-stress coupling effect, thereby improving the safety of the underground tunnel construction process.

Description

Technical Field

[0001] This invention relates to the field of water-blocking curtain monitoring technology, and in particular to a device and method for coordinated monitoring of seepage pressure stress in the surrounding rock of a water-blocking curtain and a subway structure. Background Technology

[0002] During the construction of underground tunnels, strong aquifers may be encountered. To prevent the aquifers from affecting the safe and normal construction of the tunnel, water-blocking curtains composed of cement columns and mixing piles are generally set up on both sides of the tunnel to block water from the aquifer. The water-blocking curtains are laid in the Quaternary gravel layer, with a thickness of about 40-42m. Below the Quaternary gravel layer is Tertiary weakly cemented mudstone with a thickness of more than 10m. The water level is high on both sides of the water-blocking curtain (18-20m) and low on the middle side (2-3m). The water-blocking curtains are 2m higher than the side with the high water level. The lower side of the water-blocking curtains is located 3-5m below the Tertiary weakly cemented mudstone.

[0003] During the dewatering process (i.e., before the tunnel is excavated for subway construction), the water level difference on both sides of the water-blocking curtain changes continuously, causing deformation of the water-blocking curtain. In addition, after the tunnel is excavated, both the water-blocking curtain and the outside of the tunnel will deform under the action of water pressure difference. Although existing monitoring technology can independently measure seepage pressure or stress, it lacks a means to coordinate the monitoring of the water-blocking curtain and the surrounding rock of the adjacent tunnel under the coupling effect of seepage and stress. This makes it impossible for operators to obtain stress data of the water-blocking curtain and the outside of the tunnel in a timely manner, affecting the construction process of the underground tunnel. Summary of the Invention

[0004] To overcome the shortcomings of existing monitoring technologies that lack collaborative monitoring methods for the seepage-stress coupling effect between water-blocking curtains and surrounding rock of adjacent chambers, this invention provides a multi-detection-point water-blocking curtain-subway structure surrounding rock seepage pressure stress collaborative monitoring device and method.

[0005] The technical solution is as follows: A water-blocking curtain-subway structure surrounding rock seepage pressure stress collaborative monitoring device includes two sets of first optical fibers respectively set on the side of the two water-blocking curtains near the high water level. The water-blocking curtain is composed of cement columns and mixing piles with equal spacing. The cement columns and the mixing piles with equal spacing are staggered. Each set of first optical fibers contains eight fibers. The first optical fibers are embedded in the side of the adjacent mixing piles near the high water level. Eight first stress sensors with equal spacing are set on the side of the mixing piles near the low water level. The first optical fibers are used to monitor the stress change on the side of the water-blocking curtain with high water level, and the first stress sensors are used to monitor the stress change on the side of the water-blocking curtain with low water level. The chamber is equipped with two sets of second optical fibers and two sets of second stress sensors with symmetrical distribution.

[0006] More preferably, each group of second optical fibers contains eight fibers, each group of second stress sensors contains sixty-four fibers, the second optical fibers in the same group are evenly distributed around the outside of the tunnel, and the second stress sensors in the same group are evenly distributed around the outside of the tunnel and are staggered with the second optical fibers in adjacent groups.

[0007] More preferably, a protective tube is provided on the outer side of the first optical fiber.

[0008] More preferably, a push plate is fixedly connected to the lower end of the first optical fiber, the push plate is provided with a fixing plate, and the fixing plate is fixedly connected with symmetrically distributed arc-shaped plates.

[0009] More preferably, the curved plate is made of a deformable material.

[0010] More preferably, the push plate is fixedly connected to a slide rod, the fixing plate is fixedly connected to a sleeve that is slidably connected to the adjacent slide rod, and a spring is fixedly connected between the slide rod and the adjacent sleeve.

[0011] More preferably, the protective tube is hinged with an L-shaped plate, the push plate is provided with a first limiting groove, the fixing plate is provided with a second limiting groove, the L-shaped plate slides in the adjacent first limiting groove and second limiting groove, and the L-shaped plate is used to limit the adjacent push plate.

[0012] More preferably, the L-shaped plate is fixedly connected to a limiting block, the first limiting groove and the second limiting groove have the same shape, the first limiting groove is composed of an arc-shaped part and a rectangular part that are interconnected, and the rectangular parts of the first limiting groove and the second limiting groove are both used for adjacent limiting blocks to pass through.

[0013] More preferably, a pressure plate is fixed between the L-shaped plate and the adjacent protective tube, and the pressure plate is made of an elastic material.

[0014] A monitoring method for the water-blocking curtain-subway structure surrounding rock seepage pressure stress collaborative monitoring device, based on the water-blocking curtain-subway structure surrounding rock seepage pressure stress collaborative monitoring device, includes the following specific steps:

[0015] S1: Based on the three laws of similarity, experimental simulations were conducted to carry out distribution experiments under the conditions of no excavation and excavation of the chamber, respectively, to monitor the deformation of the water-blocking curtain under the continuous change of water level difference and the stress change process under the water pressure difference between the inside and outside.

[0016] S2: Install a first stress sensor and a first optical fiber on the inner and outer sides of the water-blocking curtain, respectively, and monitor the stress changes on the inner and outer sides of the water-blocking curtain through the first stress sensor and the first optical fiber.

[0017] S3: Install a second optical fiber and a second stress sensor in sequence outside the chamber to monitor the distribution characteristics of soil stress between the water-blocking curtain and the chamber, as well as the stress outside the chamber.

[0018] S4: During the installation of the first optical fiber, the first optical fiber is first placed between two adjacent cement pillars through the protective tube. After the cement grout between the two cement pillars is poured, the protective tube is removed and the first optical fiber is brought close to the Quaternary gravel layer through the L-shaped plate.

[0019] S5: Once the protective tube is removed, the installation of the first optical fiber is complete.

[0020] The beneficial effects of this invention are as follows: By conducting experimental data testing in advance, this invention improves the accuracy of data during actual construction. Furthermore, by using a first optical fiber, a first stress sensor, a second optical fiber, and a second stress sensor to collaboratively monitor the water-blocking curtain and the surrounding rock of the adjacent chamber under the coupling effect of seepage and stress, the safety of the underground tunnel construction process is improved. The protective pipe prevents direct contact between cement slurry and the first optical fiber, avoiding damage to the first optical fiber from the impact of cement slurry during the grouting process. As the protective pipe moves upward, the L-shaped plate sequentially attaches the first optical fiber to the Tertiary weakly cemented mudstone and the Quaternary gravel layer from bottom to top, ensuring that the first optical fiber is located between the Quaternary gravel layer and the Tertiary weakly cemented mudstone and the mixing pile, thus guaranteeing the accuracy of stress monitoring data on the outside of the water-blocking curtain. Attached Figure Description

[0021] Figure 1 A schematic diagram showing the installation location of the water-blocking curtain;

[0022] Figure 2 This is a schematic diagram showing the positions of the second optical fiber and the second stress sensor relative to the chamber in this invention;

[0023] Figure 3 This is a three-dimensional structural diagram of the second optical fiber and the second stress sensor of the present invention;

[0024] Figure 4 This is a three-dimensional structural diagram of the cement column and arc-shaped plate of the present invention;

[0025] Figure 5 This is a three-dimensional structural diagram of the first optical fiber and the push plate of the present invention;

[0026] Figure 6 This is a three-dimensional structural diagram of the slide bar and sleeve of the present invention;

[0027] Figure 7 This is an exploded view of the three-dimensional structure of the push plate, fixing plate, and L-shaped plate of the present invention.

[0028] The markings in the attached diagram are as follows: 1-First optical fiber, 101-Water-blocking curtain, 102-Cement column, 103-Mixing pile, 2-First stress sensor, 3-Second optical fiber, 4-Second stress sensor, 5-Protective pipe, 6-Push plate, 601-First limiting groove, 7-Fixing plate, 701-Second limiting groove, 8-Arc plate, 9-Sliding rod, 10-Sleeve, 11-L-shaped plate, 12-Limiting block, 13-Pressure plate. Detailed Implementation

[0029] The following description is only a preferred embodiment of the present invention and does not limit the scope of protection of the present invention.

[0030] Example 1

[0031] Water-blocking curtain - a collaborative monitoring device for seepage pressure stress in the surrounding rock of subway structures, such as Figures 1-3 As shown, the system includes two sets of first optical fibers 1 respectively installed on the high water level side of two water-blocking curtains 101. Each water-blocking curtain 101 consists of cement columns 102 and mixing piles 103 distributed at equal intervals. The cement columns 102 and adjacent mixing piles 103 are staggered. Each set of first optical fibers 1 contains eight fibers. The first optical fibers 1 are embedded in adjacent mixing piles 103 on the high water level side. Eight first stress sensors 2 are installed on the low water level side of the mixing piles 103. The first optical fibers 1 are used to monitor stress changes on the high water level side of the water-blocking curtain 101, and the first stress sensors 2 are used to monitor stress changes on the low water level side of the water-blocking curtain 101. Figure 1 The Quaternary gravel layer is located above the Tertiary weakly cemented mudstone. The lower end of the water-blocking curtain 101 is inserted into the Tertiary weakly cemented mudstone. The high water level line is represented by two shorter double-dotted lines, and the low water level line is represented by one longer double-dotted line. The outer side of the two water-blocking curtains 101 is the high water level zone, and the inner side of the two water-blocking curtains 101 is the low water level zone. A through chamber is opened in the part of the inner side of the two water-blocking curtains 101 that is higher than the low water level line.

[0032] The chamber is equipped with two symmetrically distributed sets of second optical fibers 3 and two symmetrically distributed sets of second stress sensors 4. Each set of second optical fibers 3 contains eight fibers, and each set of second stress sensors 4 contains sixty-four sensors. The second optical fibers 3 in the same set are evenly distributed around the outside of the chamber, and the second stress sensors 4 in the same set are evenly distributed around the outside of the chamber and are interspersed with the second optical fibers 3 in adjacent sets. The second optical fibers 3 are used to monitor the deformation characteristics of different locations in the chamber under the action of water level difference, and the second stress sensors 4 are used to monitor the stress change process of the chamber and surrounding rock when the water level changes continuously.

[0033] This device monitors and analyzes the deformation and stress changes of the water-blocking curtain 101 under constantly changing water level differences in the case of an unexcavated tunnel, as well as the distribution characteristics of the deformation and stress on both sides of the water-blocking curtain 101, and the stress in the surrounding rock outside and in the middle of the tunnel under the action of water level differences after the tunnel is excavated. This provides a theoretical basis and scientific guidance for the safe construction and normal operation of tunnel engineering. Experimental simulations should be conducted before the formal construction of this device to ensure the accuracy of actual construction data. Its theoretical basis is the three laws of similarity, which are the fundamental theories for studying various problems in geotechnical engineering using similar material simulation tests.

[0034] The first law of similarity states that the similarity index of similar systems is equal to one, or the similarity criteria are equal. In mining applications, the model and the prototype should satisfy geometric similarity, kinematic similarity, and dynamic similarity, and the physical quantities should be proportional.

[0035] The second law of similarity states that the fundamental physical equations of two similar phenomena can be expressed as a comprehensive equation composed of similarity criteria. This law more accurately summarizes the similarity conditions of two systems.

[0036] The Third Law of Similarity states that for two phenomena to be similar, their single-valued conditions must be similar, and the similarity criteria composed of these single-valued conditions must be numerically equal. This law is a necessary and sufficient condition for phenomena to be similar.

[0037] Single-valued conditions are the conditions that all specific phenomena in a group of phenomena must satisfy, including geometric conditions, time conditions, physical conditions, boundary conditions, and initial conditions. The first and second laws of similarity are necessary conditions for phenomena to be similar, while the third law of similarity is a criterion that two phenomena must follow to be similar. All single-valued conditions in the group of phenomena must be satisfied for phenomena to be similar. It is worth noting that for some complex engineering problems, it is difficult to determine all single-valued conditions. We can only judge what the most important parameters are based on experience. This makes it difficult to truly realize the third law of similarity, and the model experimental results have approximate properties.

[0038] Specifically, in this research, the model and the physical object must be similar in the following four aspects: geometric similarity, temporal similarity, density similarity, and strength similarity. The similarity conditions used in this similarity material test are as follows:

[0039] (1) Geometric similarity ratio

[0040] Geometric similarity refers to the fact that the spatial dimensions of the model and the prototype are in a fixed proportion.

[0041]

[0042] In the formula: C l It is the geometric similarity ratio;

[0043] (2) Time similarity ratio

[0044] The experiment simulates the stress and displacement of the water-blocking curtain 101 during the piping process. As the piping develops and changes, the stress and displacement of the water-blocking curtain 101 are in a dynamic process and need to meet the time similarity requirement.

[0045]

[0046] In the formula: C t This represents the time similarity ratio.

[0047] (3) Rock bulk density similarity ratio

[0048]

[0049] In the formula: C γ γ is the bulk density similarity ratio; γ′ is the prototype bulk density, g / m³ 3 γ″ is the model bulk density, g / m³ 3 .

[0050] (4) Stress and strength similarity ratio

[0051] According to the basic formula of the similarity principle, the similarity ratio of elastic modulus, stress, and strength is:

[0052] C p =C γ ·C l =30

[0053] In the formula: C p It represents the similarity ratio of elastic modulus, stress, and strength.

[0054] The specific experiment is divided into two parts:

[0055] Experiment 1: Without excavation of the chamber, water was drawn into the water-blocking curtain 101. The deformation of the water-blocking curtain 101 and the stress change under the water pressure difference between the inside and outside were observed as the water level difference changed continuously.

[0056] (1) Deformation monitoring

[0057] On the surface of the water-blocking curtain 101 on the high water level side, eight first optical fibers 1 are vertically arranged (the first optical fibers 1 are in contact with the Quaternary gravel layer and the Tertiary weakly cemented mudstone). Each first optical fiber 1 has eight optical fiber grids, totaling sixty-four optical fiber grids (the optical fiber grids are not shown in the figure; the optical fiber grid is a periodic microstructure device manufactured inside the optical fiber through a special process). The deformation of the water-blocking curtain 101 at different heights during the test is monitored, and the deformation characteristics of the water-blocking curtain 101 at different depths after being subjected to hydraulic action are analyzed by fitting.

[0058] (2) Stress monitoring

[0059] Sixty-four first stress sensors 2 are installed on the surface of the water-blocking curtain 101 on the low water level side, respectively, to monitor the stress changes of the surrounding rock of the water-blocking curtain 101 as the water pressure difference increases.

[0060] (3) After the water-blocking curtain 101 is dewatered, continue to monitor for a period of time to observe whether the deformation and stress of the water-blocking curtain 101 will change further due to the deformation of the surrounding rock or the delay of stress.

[0061] Experiment 2: After the excavation of the chamber, the deformation of the water-blocking curtain 101 and the stress on both sides under the action of water pressure difference were monitored, as well as the distribution characteristics of the surrounding rock stress between the water-blocking curtain 101 and the chamber and the stress on the outside of the chamber.

[0062] (1) Stress monitoring

[0063] Eight sets of second stress sensors 4 are installed along the left side of the tunnel wall from the top to the bottom of the tunnel, for a total of sixty-four second stress sensors 4, to monitor the stress change process of the tunnel wall and the surrounding rock near the tunnel wall when the water level difference changes continuously.

[0064] (2) Displacement monitoring

[0065] Eight second optical fibers 3 are laid along the left side of the chamber wall. Each second optical fiber 3 has eight optical fiber grids engraved on it, for a total of sixty-four optical fiber grids. These are used to monitor the deformation characteristics of the chamber wall at different locations under the influence of water level difference.

[0066] By conducting experimental data testing in advance, the accuracy of data during actual construction is improved. Furthermore, the coordinated monitoring of the water-blocking curtain 101 and the surrounding rock of the adjacent chamber under the coupling effect of seepage and stress enhances the safety of the underground tunnel construction process.

[0067] Example 2

[0068] After the cement columns are poured, the optical fiber is placed vertically between two adjacent cement columns. Then, cement grout is poured between the two cement columns. During the pouring of cement grout, the cement grout will impact the optical fiber and cause damage to the surface of the optical fiber. At the same time, the cement grout will cause the position of the optical fiber to change, making it impossible for the optical fiber to be placed vertically between the two cement columns, thus affecting the subsequent stress monitoring process on the outside of the water-blocking curtain.

[0069] Based on Example 1, a water-blocking curtain-subway structure surrounding rock seepage pressure stress collaborative monitoring device, such as... Figure 2 and Figures 4-7As shown, a protective tube 5 is provided on the outer side of the first optical fiber 1. A push plate 6 is fixed to the lower end of the first optical fiber 1. The lower surface of the protective tube 5 contacts the upper surface of the push plate 6. A fixing plate 7 is provided on the lower side of the push plate 6. Two sets of arc-shaped plates 8 are symmetrically distributed front and back on the fixing plate 7. There are three arc-shaped plates 8 in each set. The three arc-shaped plates 8 in the same set are distributed at equal intervals. The arc-shaped plates 8 are made of deformable material and can be deformable steel plates. The fixing plate 7 drives the arc-shaped plates 8 to move downward between the two cement columns 102. The arc-shaped plates 8 deform and the fixing plate 7 can no longer drive the arc-shaped plates 8 to move upward between the two cement columns 102. A sliding rod 9 is fixed to the push plate 6. A sleeve 10 is fixed to the fixing plate 7 and is slidably connected to the adjacent sliding rod 9. The sliding connection between the sliding rod 9 and the adjacent sleeve 10 is not sealed. A spring is fixed between the sliding rod 9 and the adjacent sleeve 10 and is located inside the sleeve 10. In the initial state, the spring inside the sleeve 10 is in a charged state. The protective tube 5 is hinged with an L-shaped plate 11. The push plate 6 is provided with a first limiting groove 601, and the fixing plate 7 is provided with a second limiting groove 701. The first limiting groove 601 and the second limiting groove 701 are the same shape and aligned vertically. The L-shaped plate 11 slides within the adjacent first limiting groove 601 and second limiting groove 701. The L-shaped plate 11 is used to limit the adjacent push plate 6. The L-shaped plate 11 is fixedly connected to a limiting block 12. The first limiting groove 601 consists of an arc-shaped part and interconnected rectangular parts. The components are arranged in the following manner: In the initial state, the limiting block 12 is misaligned with the rectangular portion of the first limiting groove 601 and the rectangular portion of the second limiting groove 701. When the limiting block 12 is vertically aligned with the rectangular portion of the first limiting groove 601, the limiting block 12 can pass through the rectangular portion of the first limiting groove 601 and the rectangular portion of the second limiting groove 701. A pressure plate 13 is fixed between the L-shaped plate 11 and the adjacent protective pipe 5. The pressure plate 13 is made of elastic material and is in a compressed state in the initial state.

[0070] Figure 2 The right-side water-blocking curtain 101 is completed, while the left-side water-blocking curtain 101 is not. Only the cement columns 102 of the left-side water-blocking curtain 101 are completed; the mixing piles 103 located between adjacent cement columns 102 are not poured. The first optical fiber 1 is installed within the mixing pile 103. Therefore, the first optical fiber 1 needs to be placed between two adjacent cement columns 102 beforehand, and cement slurry needs to be poured between the two cement columns 102 to form the mixing pile 103. The mixing pile 103 enhances the connection strength between the two adjacent cement columns 102. The process of placing the first optical fiber 1 between the two adjacent cement columns 102 is as follows: In the initial state, the friction between the L-shaped plate 11 and the push plate 6 and the fixed plate 7 prevents the L-shaped plate 11 from rotating relative to the push plate 6 and the fixed plate 7. Figure 5 As shown, the limiting block 12 is located behind the rectangular portion of the first limiting groove 601 and the rectangular portion of the second limiting groove 701. The operator first arranges the first optical fiber 1, the protective tube 5, the fixing plate 7, and the arc-shaped plate 8 according to... Figure 3As shown, the curved plate 8 is gradually inserted between the two cement pillars 102. As it moves downwards, it comes into contact with and deforms the cement pillars 102. When the state is as described... Figure 4 As shown, the operator no longer moves the protective pipe 5 downwards. At this time, the fixing plate 7 is stuck between the two cement columns 102 by the six arc plates 8 and cannot move upwards or rotate. At the same time, the push plate 6, the slide rod 9 and the sleeve 10 cannot move upwards or rotate. Then, cement slurry is poured between the two cement columns 102. During the process of pouring cement slurry, the protective pipe 5 prevents the cement slurry from directly contacting the first optical fiber 1, so as to avoid the first optical fiber 1 being damaged by the impact of cement slurry during the process of pouring cement slurry.

[0071] After the cement grout is poured, the first optical fiber 1 needs to be tightly attached to the Quaternary gravel layer and the Tertiary weakly cemented mudstone on its left side. This ensures that after the cement grout solidifies, the first optical fiber 1 is located between the Quaternary gravel layer and the Tertiary weakly cemented mudstone and the mixing pile 103, allowing the first optical fiber 1 to monitor the stress changes between the Quaternary gravel layer and the Tertiary weakly cemented mudstone and the water-blocking curtain 101. The specific operation is as follows: The operator rotates the protective pipe 5 clockwise ( Figure 5 (Top view) The protective tube 5 drives the L-shaped plate 11 and the limiting block 12 to rotate clockwise. When the limiting block 12 is aligned with the rectangular portion of the second limiting groove 701, the operator stops rotating the protective tube 5. Then, the operator pulls the protective tube 5 upward, which drives the L-shaped plate 11 and the limiting block 12 to move upward. The limiting block 12 passes through the rectangular portion of the second limiting groove 701 and the rectangular portion of the first limiting groove 601 in sequence. The L-shaped plate 11 moves along the arc-shaped portion of the second limiting groove 701 and the first limiting groove in sequence. The arc-shaped part of 601 moves upward. After the L-shaped plate 11 moves out of the arc-shaped part of the first limiting groove 601, the elastic force of the spring inside the sleeve 10 is released. The sleeve 10 pushes the slide rod 9 to drive the push plate 6 to move to the left. The push plate 6 drives the lower end of the first optical fiber 1 to move to the left and stick to the tertiary weakly cemented mudstone. After the L-shaped plate 11 moves out of the first limiting groove 601, the limiting of the L-shaped plate 11 is released. The elastic force of the pressure plate 13 is released, causing the L-shaped plate 11 to rotate clockwise around the hinge point between the L-shaped plate 11 and the protective tube 5. Figure 5 (Based on the front view perspective), the lower side of the L-shaped plate 11 gradually contacts the right side of the first optical fiber 1 and pushes the first optical fiber 1 to the left. It moves upward through the protective tube 5. The L-shaped plate 11 presses the first optical fiber 1 tightly against the Tertiary weakly cemented mudstone and the Quaternary gravel layer from bottom to top, so that the first optical fiber 1 is located between the Quaternary gravel layer and the Tertiary weakly cemented mudstone and the mixing pile 103, ensuring the accuracy of the stress monitoring data on the outside of the water-blocking curtain 101. When the protective tube 5 is separated from the first optical fiber 1, the installation process of one first optical fiber 1 is completed. The protective tube 5, L-shaped plate 11, limiting block 12 and pressure plate 13 can all be recycled. Then the operator continues to repeat the above steps to install other first optical fibers 1.

[0072] Example 3

[0073] Based on Example 2, the monitoring method of the water-blocking curtain-subway structure surrounding rock seepage pressure stress collaborative monitoring device is as follows: Figures 1-7 As shown, the specific steps of the collaborative monitoring device for seepage pressure stress in the surrounding rock of the subway structure based on the water-blocking curtain are as follows:

[0074] S1: Based on the three laws of similarity, experimental simulations were conducted to carry out distribution experiments under the conditions of no excavation and excavation of the chamber, respectively, to monitor the deformation of the water-blocking curtain 101 under the continuous change of water level difference and the stress change process under the water pressure difference between the inside and outside.

[0075] S2: Install a first stress sensor 2 and a first optical fiber 1 on the inner and outer sides of the water-blocking curtain 101, respectively, and monitor the stress changes on the inner and outer sides of the water-blocking curtain 101 through the first stress sensor 2 and the first optical fiber 1.

[0076] S3: Install the second optical fiber 3 and the second stress sensor 4 in sequence outside the chamber to monitor the distribution characteristics of soil stress between the water-blocking curtain 101 and the chamber, as well as the stress outside the chamber.

[0077] S4: During the installation of the first optical fiber 1, the first optical fiber 1 is first placed between two adjacent cement pillars 102 through the protective tube 5. After the cement grout between the two cement pillars 102 is poured, the protective tube 5 is removed and the first optical fiber 1 is brought close to the fourth-order gravel layer through the L-shaped plate 11.

[0078] S5: After the protective tube 5 is removed, the installation of the first optical fiber 1 is completed.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A water-blocking curtain-subway structure surrounding rock seepage pressure stress co-monitoring device, characterized in that, It includes two sets of first optical fibers (1) respectively set on the side of the two water-blocking curtains (101) near the high water level. The water-blocking curtain (101) is composed of cement columns (102) and mixing piles (103) distributed at equal intervals. The cement columns (102) and the mixing piles (103) distributed at equal intervals are staggered. Each set of first optical fibers (1) contains eight fibers. The first optical fibers (1) are embedded in the side of the adjacent mixing piles (103) near the high water level. Eight first stress sensors (2) are set on the side of the mixing piles (103) near the low water level. The first optical fibers (1) are used to monitor the stress change on the side of the water-blocking curtain (101) near the high water level. The first stress sensors (2) are used to monitor the stress change on the side of the water-blocking curtain (101) near the low water level. The chamber is equipped with two sets of second optical fibers (3) and two sets of second stress sensors (4) symmetrically distributed. The number of the second optical fibers (3) in each group is eight, and the number of the second stress sensors (4) in each group is sixty-four. The second optical fibers (3) in the same group are evenly distributed around the outside of the tunnel, and the second stress sensors (4) in the same group are evenly distributed around the outside of the tunnel and are interleaved with the second optical fibers (3) in the adjacent groups. A protective tube (5) is provided on the outside of the first optical fiber (1); The lower end of the first optical fiber (1) is fixedly connected to a push plate (6), the push plate (6) is provided with a fixing plate (7), and the fixing plate (7) is fixedly connected to symmetrically distributed arc plates (8). The protective tube (5) is hinged with an L-shaped plate (11), the push plate (6) is provided with a first limiting groove (601), the fixing plate (7) is provided with a second limiting groove (701), the L-shaped plate (11) slides in the adjacent first limiting groove (601) and second limiting groove (701), and the L-shaped plate (11) is used to limit the adjacent push plate (6). A pressure plate (13) is fixed between the L-shaped plate (11) and the adjacent protective tube (5), and the pressure plate (13) is made of elastic material.

2. The water-blocking curtain-subway structure surrounding rock seepage pressure stress co-monitoring device according to claim 1, characterized in that, The arc-shaped plate (8) is made of a deformable material.

3. The water-blocking curtain-subway structure surrounding rock seepage pressure stress co-monitoring device according to claim 2, characterized in that, The push plate (6) is fixedly connected to a slide rod (9), the fixing plate (7) is fixedly connected to a sleeve (10) that is slidably connected to the adjacent slide rod (9), and a spring is fixedly connected between the slide rod (9) and the adjacent sleeve (10).

4. The water-blocking curtain-subway structure surrounding rock seepage pressure stress co-monitoring device according to claim 3, characterized in that, The L-shaped plate (11) is fixed to the limiting block (12). The first limiting groove (601) and the second limiting groove (701) have the same shape. The first limiting groove (601) is composed of an arc-shaped part and a rectangular part that are interconnected. The rectangular part of the first limiting groove (601) and the rectangular part of the second limiting groove (701) are both used for the adjacent limiting blocks (12) to pass through.

5. A monitoring method for the water-blocking curtain-subway structure surrounding rock seepage pressure stress co-monitoring device, as described in claim 4, characterized in that, The specific steps are as follows: S1: Based on the three laws of similarity, experimental simulations were conducted, and distribution experiments were carried out in the case of unexcavated and excavated chambers respectively to monitor the deformation of the water-blocking curtain (101) under the continuous change of water level difference and the stress change process under the water pressure difference between the inside and outside. S2: Install a first stress sensor (2) and a first optical fiber (1) on the inner and outer sides of the water-blocking curtain (101) respectively, and monitor the stress changes on the inner and outer sides of the water-blocking curtain (101) through the first stress sensor (2) and the first optical fiber (1). S3: Install the second optical fiber (3) and the second stress sensor (4) in sequence outside the chamber to monitor the distribution characteristics of soil stress between the water-blocking curtain (101) and the chamber, as well as the stress outside the chamber. S4: During the installation of the first optical fiber (1), the first optical fiber (1) is first placed between two adjacent cement pillars (102) through the protective tube (5). After the cement grout between the two cement pillars (102) is poured, the protective tube (5) is removed and the first optical fiber (1) is brought close to the Quaternary gravel layer through the L-shaped plate (11). S5: After the protective tube (5) is removed, the first optical fiber (1) is installed.

Images