Diversion tunnel structural joint water permeability monitoring device and monitoring method

Abstract

The invention discloses a diversion tunnel structural joint water permeability monitoring device and method in the field of hydraulic engineering, the detection device comprises an air bag belt, a flexible pressing plate and a pressing mechanism, a circle of air bag strip is arranged on the front face of a belt body of the air bag belt, and a water filling area with the front face open is defined by the air bag strip; the flexible pressing plate is used for being pressed on the back face of the belt body and pressing the air bag strips on the air bag belt on the inner walls of the two sides of the structural joint of the diversion tunnel under the action of the pressing mechanism. During detection, the air bag belt is compressed and fixed to the structural joint of the diversion tunnel through the compressing mechanism and the flexible pressing plate, the air bag strip is made to define a closed water filling area around the joint, the water leakage condition of the structural joint can be rapidly diagnosed by applying pressurized water into the water filling area, and compared with a traditional water storage detection mode, the water leakage condition of the structural joint can be rapidly diagnosed. The device can greatly reduce water consumption, is simple to operate and convenient to install, and improves the efficiency of diversion tunnel joint water permeability detection.

Description

Technical Field

[0001] The invention relates to the field of water conservancy projects, and in particular to a device and method for monitoring water permeability of structural seams in a water diversion tunnel. Background Art

[0002] As a water conveyance structure in water conservancy projects, tunnels have high requirements for the anti-seepage and anti-leakage properties of the tunnel itself. In tunnel construction projects, the secondary lining of the tunnel is subject to many restrictions such as the properties of concrete materials, construction methods, and construction budgets. At present, the construction is mainly carried out by pouring concrete lining in sections, and the next section of the tunnel lining concrete is poured after the previous section of the lining concrete solidifies. This method of pouring concrete in stages will cause construction joints to form on the contact surfaces of concrete at different stages after the completion of the structural construction. In addition, due to the characteristics of thermal expansion and contraction of concrete materials, expansion joints need to be set in tunnels to reserve space for concrete deformation. In order to ensure that the construction joints and expansion joints do not have quality defects such as seepage and leakage after the tunnel is put into use, the engineering generally adopts the installation of copper waterstops, rubber waterstops and other waterstops on the construction joints and expansion joints for protection as an insurance and backup waterproofing measure. It is difficult to inspect and evaluate the anti-seepage effect after the construction is completed. However, subject to the influence of many factors such as water-stopping technology, construction quality and construction process, structural joints and construction joints installed with water-stopping may also become weak links that cause water leakage. The areas where external water infiltration occurs in the construction tunnel are also concentrated in the structural joints and construction joints where there are joints in the construction process.

[0003] The conventional method for monitoring tunnel water leakage is mainly water level monitoring, which determines the amount of water leakage by monitoring the difference in water levels inside and outside the tunnel. Water level monitoring points are set up inside and outside the tunnel, and water level data are recorded regularly. By comparing the water level difference between the two monitoring points, the amount of water leakage can be estimated. This method consumes a lot of water, is cumbersome to operate, requires a lot of manpower and material resources, and the accuracy of the monitoring results is related to many factors, and cannot effectively reflect the real situation. Summary of the invention

[0004] In order to overcome the above-mentioned deficiencies of the existing tunnel water leakage monitoring methods, the technical problem to be solved by the present invention is to provide a simple and fast water permeability monitoring device and monitoring method for the structural seams of a water diversion tunnel.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A water permeability monitoring device for structural seams of a water diversion tunnel comprises an airbag belt, a flexible pressure plate and a clamping mechanism, wherein the airbag belt comprises a belt body and airbag strips arranged along the length direction on both sides of the front of the belt body, the airbag strips on both sides are connected end to end to enclose a water-filled area with an open front on the front of the belt body, the airbag belt is provided with a gas interface connected to the airbag strips, and a liquid interface connected to the water-filled area; the airbag belt comprises a plurality of strips, and can be abutted end to end to enclose a circular structure that is close to the inner wall of the water diversion tunnel, the flexible pressure plate is a plurality of arc-shaped plates that match the curvature of the inner wall of the water diversion tunnel, the clamping mechanism is located in the middle of the water diversion tunnel, and can press the flexible pressure plate against the back of the belt body by pushing outward, so that the airbag strips on both sides of the airbag belt are pressed against the inner walls on both sides of the structural seam of the water diversion tunnel.

[0007] Furthermore, the cross-section of the airbag strip when inflated is rectangular, the flexible pressing plate is a flexible steel plate, and the width of the flexible pressing plate is not less than the width of the airbag strip.

[0008] Furthermore, a transparent connecting tube is provided on the back of the belt body of the airbag belt, both ends of the connecting tube are connected to both ends of the water-filled area of ​​the airbag belt, and the flexible pressing plate is located between the back of the belt body and the connecting tube.

[0009] Furthermore, it also includes a water tank and a water pump. The liquid interface includes two, which are respectively arranged at the two ends of the airbag belt. The two liquid interfaces are connected to the water tank through a water pipe respectively, and a water pump is respectively arranged on the two water pipes.

[0010] Furthermore, both ends of the airbag belt are provided with interfaces connected to the water-filled area in the middle thereof, and the interfaces at the spliced ​​ends of two adjacent airbag belts are connected together through a rubber water stop valve.

[0011] Furthermore, the clamping mechanism includes a plurality of telescopic rods whose fixed ends are hinged to each other and have a rotationally symmetrical structure around the hinge points, and the telescopic ends of the telescopic rods abut against the flexible pressing plate.

[0012] Furthermore, the telescopic rod comprises a threaded sleeve, a force transmission rod rotatably connected to one end of the threaded sleeve, and a threaded rod threadedly connected to the other end of the threaded sleeve, and the force transmission rods of all telescopic rods are hinged together at one end away from the threaded sleeve.

[0013] The method for monitoring water permeability of structural joints in a diversion tunnel adopts the above-mentioned water permeability monitoring device for structural joints in a diversion tunnel, and comprises the following steps:

[0014] Step 1: Polish the surface around the structural joint of the water diversion tunnel to be tested, apply ointment on the surface where the airbag strips and the inner wall of the water diversion tunnel are in contact, and stick two airbag strips on the inner walls of the tunnel on both sides of the structural joint;

[0015] Step 2: Use an air pump to inflate the airbag strip through the gas interface, so that the airbag strip swells and fits against the inner wall of the tunnel, then stop inflating and close the gas interface, then press the flexible pressing plate on the back of the airbag belt, and apply pressure to the flexible pressing plate through the clamping mechanism, so that the airbag strip is pressed and fixed on the inner wall of the tunnel;

[0016] Step 3: Set a valve and a pressure gauge at the liquid interface, and use a water pump to fill water into the water filling area through the liquid interface to ensure that the water fills the entire water filling area and maintains a certain pressure, and then close the valve and the water pump;

[0017] Step 4: Determine the water permeability of the structural joints of the water diversion tunnel by observing the pressure changes on the pressure gauge.

[0018] Furthermore, any of the following methods may be used to determine water permeability:

[0019] Method 1: a transparent connecting tube is provided on the back of the belt body of the airbag belt, and the two ends of the connecting tube are connected to the two ends of the water-filled area of ​​the airbag belt. In step 3, no pressure gauge is provided, and the water permeability of the structural seam of the water diversion tunnel is judged by observing the water level change in the connecting tube;

[0020] Method 2. In step 3, a liquid interface is set at each end of the airbag belt. The two liquid interfaces are connected to the water tank through a water pump respectively. Water is filled into the water filling area by using one liquid interface to take in water and the other liquid interface to discharge water. In step 4, the water permeability of the joint is judged by observing the water level change in the water tank.

[0021] Furthermore, interfaces connected to the water-filled area in the middle are provided at both ends of the airbag belt, and the interfaces at the spliced ​​ends of two adjacent airbag belts are connected together through rubber stop valves. In step three, all rubber stop valves are opened before filling with water. If it is determined in step four that there is no leakage in the structural joint, the next structural joint is monitored; if the structural joint is leaking, all rubber stop valves are closed, and the water filling of each airbag belt is monitored in sections, thereby detecting the leakage area.

[0022] The beneficial effects of the present invention are: the airbag belt is compressed and fixed at the structural seam of the tunnel by utilizing the clamping mechanism and the flexible pressure plate, so that the airbag strip is surrounded by the structural seam to form a closed water-filled area, and the water leakage of the structural seam can be quickly diagnosed by applying pressurized water into the water-filled area. Compared with the traditional water storage method of detecting the water level difference inside and outside the tunnel, the device can greatly reduce the water consumption, and is simple to operate and easy to install, thereby improving the monitoring efficiency of the water permeability of the structural seam of the water diversion tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 It is a cross-sectional view of the airbag belt of the present invention being seamed and attached to the tunnel structure.

[0025] Marked in the figure are, 1-airbag belt, 2-flexible pressure plate, 3-clamping mechanism, 4-water diversion tunnel, 5-water tank, 6-water pump, 7-water pipe, 8-rubber water stop valve, 11-belt body, 12-airbag strip, 13-water filling area, 14-gas interface, 15-liquid interface, 16-connecting pipe, 31-threaded sleeve, 32-force transmission rod, 33-threaded rod, 41-structural seam. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings.

[0027] It should be noted that if there are directional indication terms in the present invention, such as up, down, left, right, front, and back directions and orientation terms, they are for the purpose of facilitating the description of the relative position relationship between components, and are not specific to the absolute position of the related components or the position relationship between components. They are only used to explain the relative position relationship and movement of the components in a certain posture. If the specific posture changes, the directional indication will also change accordingly. If there are terms related to quantity in the present invention, such as "multiple", "multiple", "several", etc., they specifically refer to two or more.

[0028] like Figure 1 , Figure 2 As shown, a water diversion tunnel structural seam water permeability monitoring device provided by the present invention comprises an airbag belt 1, a flexible pressing plate 2 and a pressing mechanism 3, wherein the airbag belt 1 comprises a belt body 11 and airbag strips 12 arranged along the length direction of the belt body 11 on both sides of the front surface, the airbag strips 12 on both sides are connected end to end, and a water-filled area 13 with an open front is enclosed on the front surface of the belt body 11, and the airbag belt 1 is provided with a gas interface 14 connected to the airbag strips 12, and a gas interface 14 connected to the water-filled area 13 is provided on the airbag belt 1. The airbag belt 1 comprises a plurality of strips, which can be butted end to end to form a circular structure pressed against the inner wall of the water diversion tunnel 4. The flexible pressure plate 2 is a plurality of arc-shaped plates matching the curvature of the inner wall of the water diversion tunnel 4. The clamping mechanism 3 is located in the middle of the water diversion tunnel 4 and can press the flexible pressure plate 2 against the back of the belt body 11 by pushing outward, so that the airbag strips 12 on both sides of the airbag belt 1 are pressed against the inner walls on both sides of the structural seam 41 of the water diversion tunnel 4.

[0029] The width of the water-filled area 13 in the middle of the airbag belt 1 should be greater than the width of the structural seam 41 of the water diversion tunnel 4. The number of airbag belts 1 is selected according to the size of the tunnel, and can be three or more. When arranging, each airbag belt 1 should be closely connected head to tail as much as possible, so as to monitor the water permeability of the entire structural seam 41. The airbag strip 12 is preferably made of rubber material, and the airbag strip 12 can expand elastically after inflation to ensure the sealing effect. The flexible pressing plate 2 is preferably matched with the curvature of the inner wall of the water diversion tunnel 4, and at the same time needs to have a certain hardness, so that the force of the pressing mechanism 3 can be evenly transmitted to the airbag belt 1, so as to ensure that the airbag strip 12 of the entire airbag belt 1 can be tightly attached to the inner wall of the water diversion tunnel 4 after inflation. In addition, the number of flexible pressing plates 2 can be determined according to the number of airbag belts 1, and at the same time, the flexible pressing plates 2 are also closely connected head to tail as much as possible, so that all airbag belts 1 can be pressed against the inner wall of the tunnel.

[0030] The use process of the present invention is: first, the airbag belt 1 is laid on the structural seam 41 of the water diversion tunnel 4, and the airbag strips 12 on both sides of the belt body 11 are respectively located outside the two sides of the structural seam 41, and then the airbag strips 12 are inflated through the gas interface 14. Because the cross-section of the water diversion tunnel 4 is circular, after inflation, the ends of each airbag belt 1 abut against each other, so that the airbag strips 12 can automatically fit on the inner wall of the water diversion tunnel 4, and then the flexible pressing plate 2 is pressed on the back of the airbag belt 1, and pressure is applied to the flexible pressing plate 2 through the clamping mechanism 3 to press and fix the airbag belt 1 on the inner wall of the water diversion tunnel 4. At this time, the water-filled area 13 in the middle of the airbag belt 1 forms a closed cavity with the inner wall of the structural seam 41, and finally, pressurized water is injected into the water-filled area 13 through the liquid interface 15, and the water permeability of the structural seam 41 can be judged by observing the change in water pressure.

[0031] Since the airtightness around the water-filled area 13 is mainly achieved by the airbag strip 12 and the inner wall of the water diversion tunnel 4, in order to enhance the sealing effect, the cross section of the airbag strip 12 is preferably set to be a rectangular cross section when filled with air, so that the contact area between the airbag strip 12 and the inner wall of the water diversion tunnel 4 can be increased, thereby improving the sealing effect. In addition, the pressing effect on the airbag belt 1 will also affect the sealing of the airbag strip 12 and the inner wall of the water diversion tunnel 4. Therefore, in order to make the pressing force uniform, the flexible pressing plate 2 is preferably made of a flexible steel plate. The flexible steel plate has a high hardness and a certain bending performance, and can evenly transmit the force of the pressing mechanism 3 to the entire airbag belt 1. At the same time, it can bend and deform to adapt to the arc surface structure of the inner wall of the water diversion tunnel 4, so that the airbag strip 12 and the inner wall of the water diversion tunnel 4 are closely fitted. In addition, in order to prevent the airbag strip 12 from deforming to one side, the width of the flexible pressing plate 2 should not be less than the width of the airbag belt 1, so that the force on the airbag strip 12 is perpendicular to the inner wall of the water diversion tunnel 4.

[0032] In addition to judging the water permeability by observing the change of water pressure injected into the water-filled area 13, a transparent connecting tube 16 can also be set on the back of the belt body 11 of the airbag belt 1, and the two ends of the connecting tube 16 are connected to the two ends of the water-filled area 13 of the airbag belt 1. After the pressure water is injected, the connecting tube 16 is consistent with the water level in the water-filled area 13. If there is a water leak, the liquid level of the connecting tube 16 will drop along with the liquid level in the water-filled area 13. Therefore, during the monitoring process, the water permeability of the structural seam 41 can be judged by observing the change of the liquid level in the connecting tube 16. In order to avoid the flexible pressing plate 2 pressing on the connecting tube 16 to affect the observation, the connecting tube 16 can be connected to the belt body 11 only through the two ends, and a gap is set between the connecting tube 16 and the belt body 11. The flexible pressing plate 2 can be placed between the back of the belt body 11 and the connecting tube 16, which can not only press the airbag belt 1 tightly, but also does not affect the observation of the connecting tube 16.

[0033] In addition to using the connecting pipe 16 for observation, the present application also provides another method, that is, setting a water tank 5 and two water pumps 6. The liquid interface 15 includes two, which are respectively set at the two ends of the airbag belt 1. The two liquid interfaces 15 are connected to the water tank 5 through a water pipe 7, and each of the two water pipes 7 is provided with a water pump 6. The two water pumps 6 have opposite pumping directions so as to form a section of pressurized water flow in the water-filled area 13. By controlling the pumping power of the two water pumps 6, the water pressure in the water-filled area 13 can be adjusted, thereby more accurately controlling the detection conditions. In addition, since a water injection passage is formed, it is possible to directly judge whether the structural seam 41 is leaking by observing the water level in the water tank 5. If the water level in the water tank 5 continues to drop within a period of time after reaching the predetermined pressure, it means that there is a leak in the structural seam 41.

[0034] Because the inner diameter of the water diversion tunnel 4 is generally large, in order to determine the water seepage position, interfaces connected to the water-filled area 13 in the middle are provided at both ends of the airbag belt 1, and the interfaces of the spliced ​​ends of two adjacent airbag belts 1 are connected together through a rubber stop valve 8. When the rubber stop valve 8 is opened, the water-filled areas 13 of all airbag belts 1 are connected together to form a whole, which can quickly determine whether there is a water leak in the entire structural seam 41; if there is a water leak, the rubber stop valve 8 can be closed, and then the water filling monitoring of each airbag belt 1 can be performed separately, so as to determine the water leaking position, which is convenient for subsequent maintenance.

[0035] As for the clamping mechanism 3, the solution adopted by the present invention is that the clamping mechanism 3 includes a plurality of telescopic rods whose fixed ends are hinged to each other and have a rotationally symmetrical structure around the hinge point, and the telescopic ends of the telescopic rods abut against the flexible pressure plate 2. Specifically, the telescopic rod includes a threaded sleeve 31, a force transmission rod 32 rotatably connected to one end of the threaded sleeve 31, and a threaded rod 33 threadedly connected to the other end of the threaded sleeve 31. The force transmission rods 32 of all telescopic rods are hinged together at one end away from the threaded sleeve 31. On the premise of fixing the force transmission rod 32, the threaded rod 33 can be controlled to be extended or retracted by rotating the threaded sleeve 31. In actual use, six telescopic rods are preferably used, and three flexible pressure plates 2 are used. When clamping, the ends of the three flexible pressure plates 2 are first clamped using three telescopic rods. The threaded rods 33 of the three telescopic rods can adopt a double-head structure, such as Figure 1 As shown, the ends of the two flexible pressing plates 2 are pressed simultaneously, and then the middle parts of the three flexible pressing plates 2 are pressed by the other three telescopic rods, so that the pressing effect of the flexible pressing plates 2 on the airbag belt 1 can be ensured.

[0036] In addition, the present invention also provides a method for monitoring water permeability of structural joints in a water diversion tunnel, using the above-mentioned water diversion tunnel structural joint water permeability monitoring device, and specifically further comprising the following steps:

[0037] Step 1: Polish the surface around the structural seam 41 of the water diversion tunnel 4 to be tested to make it smooth, apply ointment on the surface where the airbag strip 12 and the inner wall of the water diversion tunnel 4 are in contact, and stick two airbag strips 12 on the inner walls of the tunnel on both sides of the structural seam 41 respectively;

[0038] Step 2: Use an air pump to inflate the airbag strip 12 through the air interface 14, so that the airbag strip 12 swells and fits against the inner wall of the tunnel, then stop inflating and close the gas interface 14, then press the flexible pressing plate 2 against the back of the airbag belt 1, and apply pressure to the flexible pressing plate 2 through the clamping mechanism 3, so that the airbag strip 12 is pressed and fixed on the inner wall of the tunnel;

[0039] Step 3: Set a valve and a pressure gauge at the liquid interface 15, and use the water pump 6 to fill water into the water filling area 13 through the liquid interface 15, ensuring that the water fills the entire water filling area 13 and maintains a certain pressure, and then close the valve and the water pump 6;

[0040] Step 4: Determine the water permeability of the structural joint 41 of the water diversion tunnel 4 by observing the pressure change of the pressure gauge.

[0041] Among them, applying ointment on the airbag strip 12, on the one hand, prevents the airbag strip 12 from being scratched due to excessive roughness of the inner wall of the water diversion tunnel 4 during the expansion or compression of the airbag strip 12, and on the other hand, helps to fill the small gap between the airbag strip 12 and the inner wall of the water diversion tunnel 4, thereby improving the sealing between the airbag strip 12 and the inner wall of the aqueduct.

[0042] When judging water permeability, any of the following methods can be used:

[0043] Method 1: a transparent connecting tube 16 is provided on the back of the belt body 11 of the airbag belt 1, and the two ends of the connecting tube 16 are connected to the two ends of the water-filled area of ​​the airbag belt 1. In step 3, no pressure gauge is provided, and the water permeability of the structural seam 41 of the water diversion tunnel 4 is judged by observing the water level change in the connecting tube 16;

[0044] Method 2. In step 3, a liquid interface 15 is provided at each end of the airbag belt 1. The two liquid interfaces 15 are connected to the water tank 5 through a water pump 6 respectively. Water is filled into the water filling area 13 in the manner of one liquid interface 15 taking in water and the other liquid interface 15 discharging water. In step 4, the water permeability of the joint is judged by observing the water level change in the water tank 5.

[0045] Preferably, in order to improve the monitoring efficiency and facilitate the detection of leaking areas, interfaces connected to the water-filled area 13 in the middle are provided at both ends of the airbag belt 1, and the interfaces at the spliced ​​ends of the two adjacent airbag belts 1 are connected together through a rubber stop valve 8. In step three, all rubber stop valves 8 are opened before filling with water. If it is determined in step four that there is no leakage in the structural seam 41, the next structural seam 41 is monitored; if there is leakage in the structural seam 41, all rubber stop valves 8 are closed, and the water filling monitoring is performed on each airbag belt 1 in sections, thereby detecting the leaking area.

[0046] The present invention uses a clamping mechanism 3 and a flexible pressing plate 2 to clamp and fix the airbag belt 1 at the structural seam 41 of the water diversion tunnel 4, so that the airbag strip 12 surrounds the structural seam 41 to form a closed water-filled area 13, and the water leakage of the structural seam 41 can be quickly diagnosed by applying pressurized water to the water-filled area 13. Compared with the traditional water storage detection method, the device can greatly reduce the water consumption, and is simple to operate and easy to install, which improves the water permeability monitoring efficiency of the structural seam 41 of the water diversion tunnel 4, has good applicability and application value, and can be promoted and applied in similar detections.

Claims

1. A water permeability monitoring device for a water diversion tunnel structural joint, characterized in that: The invention comprises an airbag belt (1), a flexible pressing plate (2) and a pressing mechanism (3); the airbag belt (1) comprises a belt body (11) and airbag strips (12) arranged along the length direction of the belt body (11) on both sides of the front surface; the airbag strips (12) on both sides are connected end to end, and a water-filled area (13) with an open front is enclosed on the front surface of the belt body (11); the airbag belt (1) is provided with a gas interface (14) connected to the airbag strips (12) and a liquid interface (15) connected to the water-filled area (13). 15); the airbag belt (1) comprises a plurality of strips which can be butted end to end to form a circular structure which is close to the inner wall of the water diversion tunnel (4); the flexible pressure plate (2) is a plurality of arc-shaped plates which match the curvature of the inner wall of the water diversion tunnel (4); the pressing mechanism (3) is located in the middle of the water diversion tunnel (4) and can be pressed outward to press the flexible pressure plate (2) against the back of the belt body (11) so that the airbag strips (12) on both sides of the airbag belt (1) are pressed against the inner walls on both sides of the structural seam (41) of the water diversion tunnel (4).

2. The water permeability monitoring device for structural joints in a water diversion tunnel according to claim 1, characterized in that: The cross-section of the airbag strip (12) when inflated is rectangular, the flexible pressing plate (2) is a flexible steel plate, and the width of the flexible pressing plate (2) is not less than the width of the airbag strip (1).

3. The water permeability monitoring device for structural joints in a water diversion tunnel according to claim 1, characterized in that: A transparent connecting tube (16) is also provided on the back of the belt body (11) of the airbag belt (1), and the two ends of the connecting tube (16) are connected to the two ends of the water-filled area (13) of the airbag belt (1), and the flexible pressure plate (2) is located between the back of the belt body (11) and the connecting tube (16).

4. The water permeability monitoring device for a water diversion tunnel structural joint according to claim 1, characterized in that: It also includes a water tank (5) and a water pump (6), wherein the liquid interface (15) includes two, which are respectively arranged at the two ends of the airbag belt (1), and the two liquid interfaces (15) are respectively connected to the water tank (5) through a water pipe (7), and a water pump (6) is respectively arranged on the two water pipes (7).

5. The water permeability monitoring device for structural joints in a water diversion tunnel according to claim 1, characterized in that: Both ends of the airbag belt (1) are provided with interfaces connected to the water-filled area (13) in the middle thereof, and the interfaces at the spliced ​​ends of two adjacent airbag belts (1) are connected together via a rubber water stop valve (8).

6. The water permeability monitoring device for structural joints in a water diversion tunnel according to claim 1, characterized in that: The clamping mechanism (3) comprises a plurality of telescopic rods whose fixed ends are hinged to each other and present a rotationally symmetrical structure around the hinge points, and the telescopic ends of the telescopic rods abut against the flexible pressing plate (2).

7. The water permeability monitoring device for structural joints in a water diversion tunnel according to claim 6, characterized in that: The telescopic rod comprises a threaded sleeve (31), a force transmission rod (32) rotatably connected to one end of the threaded sleeve (31), and a threaded rod (33) threadedly connected to the other end of the threaded sleeve (31), and the ends of the force transmission rods (32) of all the telescopic rods away from the threaded sleeve (31) are hinged together.

8. A method for monitoring water permeability of structural joints in a water diversion tunnel, characterized in that: The water diversion tunnel structural joint water permeability monitoring device according to claim 1 further comprises the following steps: Step 1: polish the surface around the structural seam (41) of the water diversion tunnel (4) to be tested to make it smooth, apply ointment on the surface where the airbag strip (12) and the inner wall of the water diversion tunnel (4) are in contact, and stick two airbag strips (12) on the inner walls of the tunnel on both sides of the structural seam (41); Step 2: using an air pump to inflate the airbag strip (12) through the air interface (14) so ​​that the airbag strip (12) swells and fits against the inner wall of the tunnel, then stopping the inflation and closing the gas interface (14), and then pressing the flexible pressing plate (2) against the back of the airbag belt (1), and applying pressure to the flexible pressing plate (2) through the clamping mechanism (3) so that the airbag strip (12) is pressed and fixed on the inner wall of the tunnel; Step 3: Install a valve and a pressure gauge at the liquid interface (15), and use a water pump (6) to fill water into the water filling area (13) through the liquid interface (15), ensuring that the water fills the entire water filling area (13) and maintains a certain pressure, and then close the valve and the water pump (6); Step 4: Determine the water permeability of the structural joint (41) of the water diversion tunnel (4) by observing the pressure change of the pressure gauge.

9. The method for monitoring water permeability of structural joints in a diversion tunnel according to claim 8, characterized in that: When judging water permeability, any of the following methods can be used: Method 1: a transparent connecting tube (16) is provided on the back of the belt body (11) of the airbag belt (1), and the two ends of the connecting tube (16) are connected to the two ends of the water-filled area of ​​the airbag belt (1). In step 3, no pressure gauge is provided, and the water permeability of the structural seam (41) of the water diversion tunnel (4) is judged by observing the change of the water level in the connecting tube (16); Method 2: In step 3, a liquid interface (15) is provided at each end of the airbag belt (1), and the two liquid interfaces (15) are connected to the water tank (5) through a water pump (6) respectively. Water is filled into the water filling area (13) in a manner that one liquid interface (15) takes in water and the other liquid interface (15) discharges water. In step 4, the water permeability of the joint is determined by observing the change in the water level in the water tank (5).

10. The method for monitoring water permeability of structural joints in a diversion tunnel according to claim 8 or 9, characterized in that: Interfaces communicating with the water-filled area (13) in the middle of the airbag belt (1) are provided at both ends of the airbag belt (1), and the interfaces at the spliced ​​ends of two adjacent airbag belts (1) are connected together via rubber stop valves (8). In step three, all rubber stop valves (8) are opened before water filling. If it is determined in step four that there is no water leakage in the structural seam (41), the next structural seam (41) is monitored; if there is water leakage in the structural seam (41), all rubber stop valves (8) are closed, and water filling monitoring is performed on each airbag belt (1) in sections, thereby detecting the water leakage area.

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