Tunnel leakage determination method and tunnel leakage experiment system

Abstract

The invention discloses a tunnel leakage determination method and a tunnel leakage experiment system.The tunnel leakage experiment system comprises a servo pressure experiment device, a digital image device and a data storage device.The tunnel leakage determination method comprises the steps that the servo pressure experiment device conducts multiple sets of dynamic load loading experiments on a soil body, applying information under each group of dynamic load loading experiments is obtained; the digital image device collects leakage information of each group of dynamic load loading experiments carried out by the servo pressure experiment device; the data storage device obtains relation information between the pore pressure of the soil body and the through joint threshold value according to the multiple sets of application information and the corresponding leakage information, leakage prediction is conducted on the target tunnel according to the relation information, and a prediction result is obtained. According to the method, the target tunnel is monitored by determining the relation between the soil body pore pressure and the leakage threshold value, whether remedial measures are taken or not is judged, tunnel leakage can be prevented, and tunnel safety is improved.

Description

Technical Field

[0001] The present application relates to the technical field of tunnel leakage prediction, and in particular to a tunnel leakage determination method and a tunnel leakage experimental system. Background Art

[0002] Tunnel engineering is an important transportation infrastructure, and tunnel leakage has always been one of the common diseases in tunnel engineering. Tunnel leakage not only affects the service life and structural safety of the tunnel, but may also cause accidents such as ground collapse, posing a threat to people's lives and property safety. Therefore, effective observation and analysis of tunnel leakage is crucial to ensure the safe operation of the tunnel.

[0003] Among the current research methods for tunnel leakage, most of them use different specific methods to monitor the changes in the content of materials (water, soil, sand and gravel, etc.) inside the tunnel after leakage occurs, and then determine whether it is a leakage, and finally carry out repairs. However, this often cannot determine whether tunnel leakage will cause ground collapse, thereby leading to safety accidents.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] The main purpose of the present application is to provide a method for determining tunnel leakage and a tunnel leakage test system, aiming to solve the problem in the prior art that after a tunnel leakage occurs, the change in the material content inside the tunnel is monitored to determine whether the tunnel is leaking and then repair it, but it is impossible to determine whether the tunnel leakage will cause ground collapse, resulting in the inability to prevent tunnel leakage.

[0006] A first aspect of an embodiment of the present application provides a method for determining tunnel leakage, which is applied to a tunnel leakage test system. The tunnel leakage test system includes a servo pressure test device, a digital image device and a data storage device. The servo pressure test device and the digital image device are respectively connected to the data storage device, and soil is contained in the servo pressure test device. The tunnel leakage determination method includes the following steps: the servo pressure test device performs multiple groups of dynamic load loading experiments on the soil to obtain application information under each group of dynamic load loading experiments, wherein the sizes of through cracks corresponding to each group of dynamic load loading are different; the digital image device collects leakage information of each group of dynamic load loading experiments performed by the servo pressure test device; the data storage device obtains the relationship information between the pore pressure of the soil and the through crack threshold according to the multiple groups of application information and the corresponding leakage information, and predicts the leakage of the target tunnel according to the relationship information to obtain a prediction result; wherein the through crack threshold is the size of the through crack at which the soil collapses under the pore pressure.

[0007] In a possible implementation, the leakage information includes a critical leakage amount under each set of dynamic load loading experiments; the digital imaging device collects leakage information of each set of dynamic load loading experiments performed by the servo pressure test device, specifically including: for each set of dynamic load loading experiments, the digital imaging device obtains first image information during the experiment, and obtains second image information during the experiment after the leak-stop plate of the servo pressure test device is opened; the digital imaging device obtains the critical leakage amount corresponding to the servo pressure test device based on multiple sets of the first image information and the corresponding second image information.

[0008] In a possible implementation, the applied information includes the soil pore pressure of the soil and the current through-crack size of the corresponding servo pressure test device under each set of dynamic load loading tests; the data storage device obtains the relationship information between the pore pressure of the soil and the through-crack threshold value according to multiple sets of the applied information and the corresponding leakage information, specifically including: the data storage device determines the through-crack threshold value corresponding to the servo pressure test device according to multiple sets of the soil pore pressures, the current through-crack size and the corresponding critical leakage amount; the data storage device obtains the relationship information between the pore pressure of the soil and the through-crack threshold value according to multiple sets of the pore pressures and the corresponding through-crack threshold values.

[0009] In a possible implementation, the prediction result includes tunnel remediation and normal tunnel operation; the leakage prediction of the target tunnel is performed according to the relationship information to obtain the prediction result, which specifically includes: obtaining a target through-crack size and a target pore pressure when a through-crack appears in the target tunnel; determining a target through-crack threshold of the target tunnel according to the relationship information and the target pore pressure; if the difference between the target through-crack size and the target through-crack threshold is less than a preset value, determining that the prediction result is tunnel remediation; if the difference between the target through-crack size and the target through-crack threshold is greater than or equal to the preset value, determining that the prediction result is normal tunnel operation.

[0010] A second aspect of an embodiment of the present application further provides a tunnel leakage test system for implementing the tunnel leakage determination method described in any one of the above-mentioned schemes, wherein the tunnel leakage test system comprises a servo pressure test device, a digital imaging device and a data storage device, wherein the servo pressure test device contains soil; the servo pressure test device is used to perform multiple groups of dynamic load loading experiments on the soil to obtain application information under each group of dynamic load loading experiments, wherein the size of the through-cracks corresponding to each group of dynamic load loading is different; the digital imaging device is used to collect leakage information of each group of dynamic load loading experiments performed by the servo pressure test device; the data storage device is used to obtain the relationship information between the pore pressure of the soil and the through-crack threshold value based on the multiple groups of application information and the corresponding leakage information, and predict the leakage of the target tunnel based on the relationship information to obtain a prediction result; wherein the through-crack threshold value is the size of the through-crack at which the soil collapses under the pore pressure.

[0011] Optionally, in one embodiment of the present application, the servo pressure experimental device includes a servo press and a compression box, the compression box contains saturated soil, and the servo press is used to provide dynamic loads of different sizes and frequencies applied to the soil; the servo press is provided with a force plate, and the lower part of the compression box is connected to a bottom plate, and the force plate and the bottom plate are connected by a rubber membrane, so that a sealed environment is formed between the force plate and the compression box, and the force plate moves in the compression box to apply a dynamic load to the soil.

[0012] Optionally, in one embodiment of the present application, the base plate is connected to leakage plates with different sizes of through-slots, an open groove is provided on the base plate, the leakage plate is arranged opposite to the open groove, each group of dynamic load loading experiments corresponds to the leakage plates with different sizes of through-slots, so that the soil after the dynamic load loading experiment leaks through the leakage plates; the base plate is also connected to a leakage-stopping plate corresponding to the through-slot of the leakage plate, and the leakage-stopping plate is connected to the leakage plate in the dynamic load loading experiment.

[0013] Optionally, in one embodiment of the present application, a waterproof rubber ring is provided on the leakage plate, and the leakage plate is connected to the base plate via the waterproof rubber ring; the leakage-stopping plate includes a four-corner frame and a clamping plate connected to each other, and the four-corner frame is fixedly connected to the outside of the base plate.

[0014] Optionally, in one embodiment of the present application, the compression box is made of an acrylic plate, and the bottom plate and the quadrilateral frame are made of stainless steel.

[0015] Optionally, in one embodiment of the present application, a plurality of connecting plates are provided on the force plate, a connecting hoop is provided on the upper portion of the compression box, one end of the rubber membrane is fixedly connected to the plurality of connecting plates, and the other end of the rubber membrane is fixedly connected to the connecting hoop.

[0016] Beneficial effect: The present application provides a method for determining tunnel leakage and a tunnel leakage test system. The method uses a servo pressure test device to perform multiple groups of dynamic load loading tests on the soil with different pore pressures. A digital imaging device collects leakage conditions during the dynamic load loading tests. A data storage device processes the above data to determine the relationship between the pore pressure of the soil and the leakage threshold, thereby monitoring the target tunnel and determining whether to take remedial measures, thereby preventing tunnel leakage and improving tunnel safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is the overall structure diagram of the preferred embodiment of the tunnel leakage test system of the present application; Figure 2 This is a disassembled structural diagram of a servo pressure test device in a preferred embodiment of the tunnel leakage test system of the present application; Figure 3 It is an assembly diagram of the connection between the bottom plate, the leakage plate and the leakage-stopping plate in the preferred embodiment of the tunnel leakage test system of the present application; Figure 4 It is an assembly diagram of the connection between the leakage plate and the leakage-stopping plate in a preferred embodiment of the tunnel leakage test system of the present application; Figure 5 It is a structural diagram of the bottom plate in a preferred embodiment of the tunnel leakage test system of the present application; Figure 6 This is a structural diagram of the bottom plate from another perspective in a preferred embodiment of the tunnel leakage test system of the present application; Figure 7 It is a structural diagram of a leakage plate in a preferred embodiment of the tunnel leakage test system of the present application; Figure 8 This is a structural diagram of a leak-stopping plate in a preferred embodiment of the tunnel leakage test system of the present application; Fig. 9 It is a position relationship diagram of the lower plane of the force application plate and the upper plane of the compression box in a preferred embodiment of the tunnel leakage test system of the present application; Fig.10It is a flow chart of a preferred embodiment of the tunnel leakage determination method of the present application; Fig.11 It is a pore pressure increment diagram of a preferred embodiment of the tunnel leakage determination method of the present application; Fig.12 It is a flowchart of specific implementation steps in a preferred embodiment of the tunnel leakage determination method of the present application.

[0019] Description of reference numerals: 10. Servo pressure test device; 20. Digital imaging device; 30. Data storage device; 11. Servo press; 12. Compression box; 13. Rubber membrane; 111. Force plate; 121. Connecting hoop; 122. Bottom plate; 1221. Opening groove; 123. Leakage plate; 124. Leak-proof plate; 125. Waterproof rubber ring.

[0020] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and effect of the present application clearer and more specific, the technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. The described embodiments are only possible technical implementations of the present application, not all possible implementations. Based on the embodiments in the present application, those skilled in the art can completely combine the embodiments of the present application to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of the present application.

[0022] In the related technology, there are many reasons for tunnel leakage. In the current research methods of tunnel leakage, most of them are to determine whether it is a leakage and then repair it after the tunnel leakage occurs. However, this often cannot determine whether the tunnel leakage will cause ground collapse, thereby leading to safety accidents. Such methods have certain limitations; utilizing the characteristics of the expansion and contraction medium that expands when absorbing water and contracts when losing water, the amount of leakage is monitored by the position change of the active plug. This method is too dependent on the material properties of the active plug and is greatly affected by the aging of the active plug; an adjustable leak is provided to apply water pressure to the box through a hydraulic loading device to simulate the leakage of the shield tunnel under different water pressures. However, the causes of tunnel leakage are not analyzed and it cannot contribute to the prevention of tunnel leakage.

[0023] The following describes the tunnel leakage determination method and tunnel leakage test system of the embodiment of the present application with reference to the accompanying drawings. In view of the problem that in the above-mentioned related art, after a tunnel leakage occurs, the change of the material content inside the tunnel is monitored to determine whether the tunnel is leaking and repaired, but it is impossible to determine whether the tunnel leakage will cause ground collapse and thus fail to prevent tunnel leakage, the present application provides a tunnel leakage determination method, in which a servo pressure test device is used to perform multiple groups of dynamic load loading experiments with different pore pressures on the soil, a digital image device collects the leakage of the dynamic load loading experiment, and a data storage device processes the above data to determine the relationship between the pore pressure of the soil and the leakage threshold, thereby monitoring the target tunnel and determining whether to take remedial measures, thereby preventing tunnel leakage and improving tunnel safety. Thus, the technical problem that in the related art, after a tunnel leakage occurs, the change of the material content inside the tunnel is monitored to determine whether the tunnel is leaking and repaired, but it is impossible to determine whether the tunnel leakage will cause ground collapse and thus fail to prevent tunnel leakage is solved.

[0024] This application explores the leakage phenomenon in the tunnel caused by dynamic response, thereby effectively preventing tunnel leakage and its hazards.

[0025] The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0026] First, the following will be combined with the attached Figure 1 , the tunnel leakage experiment system of the embodiment of the present application is introduced.

[0027] like Figure 1 As shown, the tunnel leakage test system includes a servo pressure test device 10, a digital image device 20 and a data storage device 30, wherein the servo pressure test device 10 and the digital image device 20 are respectively connected to the data storage device 30, and the servo pressure test device 10 contains soil; the servo pressure test device 10 is used to perform multiple groups of dynamic load loading tests on the soil to obtain application information under each group of dynamic load loading tests, wherein the sizes of the through cracks corresponding to each group of dynamic load loading are different; the digital image device 20 is used to collect the leakage information of each group of dynamic load loading tests performed by the servo pressure test device 10; the data storage device 30 is used to obtain the relationship information between the pore pressure of the soil and the through crack threshold according to the multiple groups of application information and the corresponding leakage information, and perform leakage prediction on the target tunnel according to the relationship information to obtain the prediction result; wherein the through crack threshold is the size of the through crack at which the soil collapses under the pore pressure.

[0028] Specifically, the servo pressure experiment device 10 is arranged opposite to the digital imaging device 20. The digital imaging device 20 is a DIC data acquisition system. DIC is differential interference (Differential Interference Contrast). The DIC data acquisition system mainly includes a CCD (Charge Coupled Device) camera and a computer with a related processing software program. DIC technology is an advanced non-contact optical measurement method. Its core principle is to use image comparison to measure the deformation and displacement of an object. First, a random speckle pattern is generated on the surface of the object to be measured. These speckles can be artificially sprayed black and white spots, or use the natural texture of the object surface; then, use an imaging device such as a CCD camera to take images of the object surface before and after the experiment, and input these images into the computer; secondly, use a related algorithm to compare the images before and after the deformation, and calculate the displacement and strain of the object surface by matching the speckle pattern in the image; finally, the software program processes the related calculations to obtain the deformation information (displacement field, strain field) of the whole field.

[0029] The data storage device 30 is a storage system, which mainly includes a computer. The various experimental data obtained by the servo pressure test device 10 and the DIC data acquisition system are matched one by one with the tunnel crack threshold value causing ground collapse using the specific algorithm of the built-in software program, and the corresponding relationship is stored in the computer. The data files, programs and the corresponding relationship between the two processed by this system can be opened on other computers.

[0030] In one embodiment of the present application, the servo pressure experimental device 10 includes a servo press 11 and a compression box 12, the compression box 12 contains saturated soil, and the servo press 11 is used to provide dynamic loads of different sizes and frequencies applied to the soil; the servo press 11 is provided with a force plate 111, and the lower part of the compression box 12 is connected to a bottom plate 122, and the force plate 111 and the bottom plate 122 are connected by a rubber membrane 13, so that a sealed environment is formed between the force plate 111 and the compression box 12, and the force plate 111 moves in the compression box 12 to apply a dynamic load to the soil.

[0031] See also Figure 2 The servo pressure test device 10 includes two parts. The first part is a servo press 11, which mainly provides dynamic loads of different sizes and frequencies and can accurately record the stroke and time of the dynamic application; the second part is a soil compression box 12, which mainly provides a place for soil compression to achieve visualization. The lower part of the compression box 12 is fixedly connected to the bottom plate 122 by bolts.

[0032] In one embodiment of the present application, a plurality of connecting plates are provided on the force plate 111 , a connecting hoop 121 is provided on the upper portion of the compression box 12 , one end of the rubber membrane 13 is fixedly connected to the plurality of connecting plates, and the other end of the rubber membrane 13 is fixedly connected to the connecting hoop 121 .

[0033] Specifically, in order to achieve the accumulation of pore pressure of the soil in the compression box 12, the sealing of the device needs to be ensured, so four connecting plates (i.e., four L-shaped plates) are added to the force plate 111 to fix one end of the rubber membrane 13. The function of the rubber membrane 13 is to form a sealing condition between the force plate 111 and the compression box 12. A connecting hoop 121 (i.e., a square hoop) is provided on the upper part of the box body of the compression box 12, which is connected to the rubber membrane 13 through the connecting hoop 121 to fix the other end of the rubber mold.

[0034] In one embodiment of the present application, Figure 3 and Figure 4 As shown, the bottom plate 122 is connected to the leakage plates 123 with different sizes of through-slots, and an open groove 1221 (i.e., a gap) is provided on the bottom plate 122. The leakage plates 123 are arranged opposite to the open groove 1221. Each group of dynamic load loading experiments corresponds to the leakage plates 123 with different sizes of through-slots, so that the soil after the dynamic load loading experiment leaks through the leakage plates 123. The bottom plate 122 is also connected to a leakage-stopping plate 124 corresponding to the through-slot of the leakage plate 123, and the leakage-stopping plate 124 is connected to the leakage plate 123 in the dynamic load loading experiment.

[0035] It should be noted that the leakage plates 123 of different specifications (i.e., different leakage sizes of the through-slots) are all opposite to the open grooves 1221, that is, the leakage plates 123 are installed in the gaps of the bottom plate 122. After the dynamic load is applied to the soil, the soil can flow out through the through-slots of the leakage plates 123 by releasing the leakage plates 123 (i.e., opening the leakage-stop plates 124).

[0036] Specifically, the embodiment of the present application controls the size of the through seam, which is mainly reflected in the connection design between the bottom plate 122 and the leakage plate 123, see Figure 5 , Figure 6 and Figure 7 The upper part of the bottom plate 122 is concave, which is consistent with the size of the compression box 12, ensuring the sealing between the compression box 12 and the bottom plate 122. A gap for the leakage plate 123 is left at the lower part of the bottom plate 122. The bottom plate 122 and the leakage plate 123 are fixed with bolts. A circle of waterproof rubber ring 125 is set on the leakage plate 123 to ensure the sealing between the bottom plate 122 and the leakage plate 123, thereby meeting the soil pore pressure accumulation requirements of the compression box 12. By replacing the leakage plates 123 of different sizes, the influence of different sizes of through-slits on the experiment is studied.

[0037] In one embodiment of the present application, Figure 4 and Figure 8 As shown, a waterproof rubber ring 125 is provided on the leakage plate 123, and the leakage plate 123 is connected to the bottom plate 122 through the waterproof rubber ring 125; the leakage-stopping plate 124 includes a four-corner frame and a clamping plate connected to each other, and the four-corner frame is fixedly connected to the outside of the bottom plate 122.

[0038] See also Figure 3 , Figure 4 and Figure 8 In order to ensure the sealing of the experimental device before the formal experiment, the leak-proof plate 124 that can match the size of the through-slit is connected to the bottom plate 122. The size of the leak-proof plate 124 corresponds to the through-slit of the leakage plate 123 one by one, and it is fixed to the outside of the bottom plate 122 with bolts. In other words, leakage plates 123 of different specifications (different sizes of through-slits) correspond to one leak-proof plate 124.

[0039] In one embodiment of the present application, the material of the compression box 12 is acrylic plate, and the material of the bottom plate 122 and the four corner frames is stainless steel. Specifically, the box body of the compression box 12 is made of acrylic plate, and in order to meet the load-bearing requirements, the bottom plate 122 and the four corner frames are made of stainless steel; It should be noted that since the size of the force plate 111 is consistent with the inner wall size of the compression box 12 and the servo press 11 and the compression box 12 are two independent structures, it is necessary to ensure that the force plate 111 can smoothly enter the inner wall of the compression box 12 to move up and down, so the positioning between the two is particularly important. Fig. 9 As shown, a miniature measuring instrument is placed at point O in the middle of the bottom of the force plate 111 to measure the distance between point O and the four corner points of the inner wall plane of the compression box 12, that is, the length of the chords OA, OB, OC, and OD. If the lengths of the four chords are equal, it proves that the positioning is successful. Otherwise, the positioning is unsuccessful and the servo press 11 issues an alarm. Similarly, this positioning system can also verify whether the compression box 12 is tilted due to a large number of tests. The distance L from the measuring instrument point O to the inner wall plane of the compression box 12 can be measured first (the distance from point O to the bottom of the compression box 12 minus the height of the compression box 12 can be obtained), and then the angles of each chord with the vertical line OO1 can be measured, and then the four chords can be calculated at this angle in the y direction (that is, Fig. 9 If the projection length is equal to the distance L, the compression box 12 is intact, otherwise the compression box 12 is damaged.

[0040] Next, a method for determining tunnel leakage according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0041] The tunnel leakage determination method described in the preferred embodiment of the present application is applied to the above-mentioned tunnel leakage experimental system, such as Fig.10 As shown, the tunnel leakage determination method comprises the following steps: In step S101, the servo pressure test device performs multiple groups of dynamic load loading experiments on the soil to obtain application information under each group of dynamic load loading experiments, wherein the sizes of the through cracks corresponding to each group of dynamic load loading are different.

[0042] It should be noted that in each dynamic load loading experiment, the soil is dynamically loaded by the pressure set by the servo pressure test device to obtain soil with different pore pressures, and then the size of the through-slit is adjusted (i.e., using seepage plates of different specifications) to explore the influence of different through-slit sizes on the leakage of the device. The DIC data acquisition system is used to observe the leakage of soil with different pore pressures under the influence of through-slits of different sizes. The storage system records the tunnel through-slit threshold value at which large-scale collapse will occur under each pore pressure (different pore pressures) of the soil, and records the relationship between the pore pressure and the through-slit threshold value, determines the target through-slit size of the target tunnel (monitored tunnel or tunnel to be predicted) and the target through-slit threshold value determined by the relationship, and if the two do not meet the conditions for disasters, real-time monitoring of data and maintenance are performed. If the two are close to the conditions for disasters, emergency remedial measures must be taken to prevent disasters. Thus, the present application can achieve the effect of preventing ground collapse accidents caused by tunnel leakage.

[0043] In order to achieve the effect of pore pressure accumulation in the soil in the compression box, a pre-experiment was carried out with a small model box before the formal experiment. The experimental results are shown in the figure. Fig.11 As shown in the figure, under the sealed condition, the pore pressure of the soil will change significantly after the dynamic load is applied. The pore pressure in the AB section changes greatly due to the initial load application, showing an exponential growth trend; this pre-experiment is artificial force loading, and the pore pressure change in the BC section is greatly affected by the dynamic loading frequency; in the CD section, the pore pressure of the soil remains basically unchanged due to the sealing of the small model box after the dynamic load is removed; in the DE section, the rubber membrane is removed, the model box has no sealing, and the pore pressure dissipates instantly. It is concluded that this device idea can achieve the effect of pore pressure accumulation and keeping the pore pressure unchanged, and its effect is closely related to the sealing of the device.

[0044] In a possible implementation, the applied information includes the soil pore pressure of the soil under each set of dynamic load loading tests and the corresponding current through-slit size of the servo pressure test device.

[0045] Specifically, the experimental device is prepared and checked to ensure the integrity and sealing of the experimental device: the various parts of the servo pressure experimental device are correctly connected, and the joints are checked for leaks by filling the compression box with water. Soil filling and saturation are carried out to prepare the soil required for the experiment and ensure that it is in a saturated state: one end of the rubber membrane is fixed on the force plate, sand is filled into the compression box in layers and compacted, water is injected and left to stand for 24-36 hours to saturate the soil, and the other end of the rubber membrane is fixed on the hoop plate. After the DIC system is calibrated, dynamic load is applied to apply dynamic load through the servo press so that the soil reaches the predetermined pore pressure: the positioning system is used to ensure the accurate positioning between the servo press and the compression box, and pre-pressing is performed to observe whether there is any situation that is not conducive to the upward and downward movement of the force plate. According to the experimental requirements, dynamic load is applied through the servo press so that the soil reaches the predetermined pore pressure.

[0046] In the embodiment of the present application, first, during the sealing inspection of the device, before the formal experiment, the various parts of the servo pressure test device are connected, and then the compression box is filled with water to see if there is any leakage at each joint. Then, during the process of filling the sand and saturating it, one end of the rubber membrane is first fixed to the force plate, and the compression box is filled with sand, compacted and filled with water in layers, and left to stand for 24-36 hours. At this time, the state of the sand should be saturated, and there is a certain consolidation force between the soil bodies. Then the other end of the rubber membrane is fixed to the hoop plate to complete the preparation work.

[0047] Then, during the process of loading the dynamic load by the servo press, according to the positioning system described above, the servo press and the compression box need to be positioned using the positioning system; before formal loading, a pre-loading step is required, that is, a dynamic load of smaller size, lower frequency and shorter time is loaded by the servo press to observe whether there is any inclination between the force plate and the compression box, which is not conducive to the upward and downward movement of the force plate; after completing the above steps, the dynamic load loading of the formal experiment can be started. The size, frequency and duration of the dynamic load can be controlled by the servo press, so that the pore pressure accumulation effect achieved by the dynamic load applied in each group of tests is different. The general control variable method can be used to analyze the influence of the size, frequency and time of the dynamic load on the pore pressure, so that each group of experiments can have soil with different pore pressures.

[0048] Finally, open the leak-proof plate. When the soil pore pressure reaches the predetermined value (such as 10kPa, 20kPa, etc.), the size, frequency and duration of the dynamic load can be recorded first. Then, open the leak-proof plate and observe the leakage phenomenon. The through-slits of each group of experiments are different, and different leakage phenomena can be observed.

[0049] In step S102, the digital imaging device collects leakage information of each group of dynamic load loading experiments performed by the servo pressure testing device.

[0050] In a possible implementation, the leakage information includes a critical leakage amount under each group of dynamic load loading experiments. For each group of dynamic load loading experiments, the digital imaging device obtains first image information during the experiment, and obtains second image information during the experiment after the leak-proof plate of the servo pressure experiment device is opened; the digital imaging device obtains the critical leakage amount corresponding to the servo pressure experiment device based on multiple groups of the first image information and the corresponding second image information.

[0051] Specifically, the DIC system is calibrated to ensure the accuracy and reliability of the DIC data acquisition system. Leakage observation and recording are carried out to observe and record the leakage phenomenon and leakage amount under different sizes of through-slits: after the soil pore pressure reaches the predetermined value, the leakage-stopping plate is opened, the leakage phenomenon under different sizes of through-slits is observed and recorded, and the data is processed using the DIC system to obtain the percentage of leakage amount.

[0052] In an embodiment of the present application, during the calibration process of the digital image device, the camera is first installed and ensured to be aligned with the center of the compression box, and the resolution, focal length and other settings of the camera are ensured to meet the experimental requirements; secondly, a calibration plate of known size (such as a chessboard or a dot array) is used to ensure that its surface has a good texture, and multiple images of the calibration plate are taken at different angles and positions to capture different perspectives; then, image processing software is used to identify feature points (such as corner points or the center of a circle) in the calibration image, and the camera calibration algorithm is used to calculate the intrinsic parameters of the camera, including focal length, principal point, distortion coefficient, etc., based on the known feature point positions and image coordinates, and the external parameters (position and posture) of the camera relative to the calibration plate are calculated to accurately describe the position of the camera in three-dimensional space; finally, the accuracy of the calibration result is checked, the reprojection error is calculated, the reliability of the calibration is evaluated, and the optimal calculated internal and external parameters of the camera are saved.

[0053] It should be noted that the percentage of seepage volume to the total soil volume is the focus of the experiment. It is generally believed that the smaller the seepage volume to the total soil volume, the better, and the larger the seepage volume, the easier it is to cause ground collapse.

[0054] In the embodiment of the present application, after the device is tested and different leakage phenomena are observed, it can be determined what leakage volume will cause large-scale collapse (using a digital imaging device to process the data and obtain the percentage of leakage), and this leakage volume is defined as the critical leakage volume.

[0055] In step S103, the data storage device obtains the relationship information between the pore pressure of the soil and the through-crack threshold value based on multiple groups of the applied information and the corresponding leakage information, and predicts the leakage of the target tunnel based on the relationship information to obtain a prediction result; wherein the through-crack threshold value is the size of the through-crack at which the soil collapses under the pore pressure.

[0056] In a possible implementation, the data storage device determines the corresponding through-crack threshold of the servo pressure test device based on multiple sets of the soil pore pressures, the current through-crack size and the corresponding critical leakage amount; the data storage device obtains the relationship information between the pore pressure of the soil and the through-crack threshold based on the multiple sets of the pore pressures and the corresponding through-crack thresholds.

[0057] Specifically, data processing and recording are carried out to determine the corresponding relationship between the pore pressure and the threshold of the crack: determine the critical leakage, that is, the leakage that causes large-scale collapse; under a specific pore pressure, find the size of the crack corresponding to the leakage reaching the critical leakage, that is, the crack threshold; record the corresponding relationship between the pore pressure and the crack threshold, and store the experimental results.

[0058] In the embodiment of the present application, during the process of computer processing and recording data, after each group of experiments goes through the above steps, each group of experiments can obtain: soil with a certain pore pressure, leakage phenomenon of different through-crack sizes and leakage amount. Under a specific pore pressure, the through-crack size corresponding to the critical leakage amount after the experiment is completed is called the through-crack threshold. Therefore, by replacing seepage plates of different sizes, a soil with a pore pressure can have different leakage phenomena, that is, different leakage amounts; similarly, by controlling the relevant parameters of the servo press, the same through-slit size can have soils with different pore pressures and different leakage amounts; the pore pressure and through-slit size of the soil can be arranged and combined, and each different combination of pore pressure and through-slit requires a set of experiments to verify. For example, multiple groups of experiments are conducted as mentioned above, and the leakage conditions and data of soils with different pore pressures under different through-slits are processed. Under a specific combination of soil pressure and through-slit size, if the leakage amount after the experiment can reach the critical leakage amount, the through-slit size under this experimental condition is used as the through-slit threshold under the pore pressure condition, and the corresponding relationship between the pore pressure and the through-slit threshold is recorded to complete the matching between multiple groups of pore pressures and through-slit thresholds, and finally the obtained experimental results are stored for subsequent use.

[0059] In a possible implementation, the prediction result includes tunnel remediation and tunnel normal operation. The target crack size and target pore pressure when a crack appears in the target tunnel are obtained; the target crack threshold of the target tunnel is determined according to the relationship information and the target pore pressure; if the difference between the target crack size and the target crack threshold is less than a preset value, the prediction result is determined to be tunnel remediation; if the difference between the target crack size and the target crack threshold is greater than or equal to the preset value, the prediction result is determined to be tunnel normal operation.

[0060] In the embodiments of the present application, after conducting multiple groups of experiments, the relationship between the pore pressure and the crack threshold was obtained, and the experimental results were applied to actual projects to prevent ground collapse accidents, thereby contributing to the prevention of ground collapse. When a crack appears in the target tunnel, the size of the crack and the pore pressure of the corresponding soil are measured first. If the size of the crack is close to the threshold, emergency measures must be taken immediately for remediation, such as ground control, suspension of tunnel operations, etc., and remedial measures must be taken in a timely manner to avoid casualties caused by ground collapse; if the size of the crack is much smaller than the threshold, the tunnel can be used normally, and the tunnel leakage must be repaired, which effectively prevents ground collapse accidents caused by tunnel leakage.

[0061] like Fig.12 As shown, the tunnel leakage determination method of the present application is further described below through specific embodiments: First, soil with different pore pressures is obtained through the servo pressure test device, and then different seepage plates are used to explore the leakage of soil with different crack sizes in the experimental device. Secondly, based on the experimental phenomena observed by the DIC data acquisition system and the experimental data obtained, the tunnel crack threshold at which large-scale collapse will occur under various pore pressures of the soil is obtained. Finally, the storage system is used to store and record the relationship between the two. If the conditions between the two do not meet the conditions for disasters, real-time monitoring of data and maintenance are carried out; if the conditions between the two are close to the conditions for disasters, emergency remedial measures must be taken to prevent disasters.

[0062] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0063] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0064] It should be understood that the application of the present application is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to this application.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining tunnel leakage, characterized in that: Applied to a tunnel leakage test system, the tunnel leakage test system comprises a servo pressure test device, a digital image device and a data storage device, the servo pressure test device and the digital image device are respectively connected to the data storage device, and soil is contained in the servo pressure test device; The tunnel leakage determination method comprises: The servo pressure test device performs multiple groups of dynamic load loading tests on the soil to obtain application information under each group of dynamic load loading tests, wherein the sizes of the through cracks corresponding to each group of dynamic load loading are different; The digital imaging device collects leakage information of each group of dynamic load loading experiments performed by the servo pressure test device; The data storage device obtains the relationship information between the pore pressure of the soil and the crack threshold value based on multiple groups of the applied information and the corresponding leakage information, and predicts the leakage of the target tunnel based on the relationship information to obtain the prediction result; wherein the crack threshold value is the size of the crack at which the soil collapses under the pore pressure.

2. The method for determining tunnel leakage according to claim 1, characterized in that: The leakage information includes the critical leakage amount under each set of dynamic load loading experiments; The digital imaging device collects leakage information of each group of dynamic load loading experiments performed by the servo pressure test device, specifically including: For each group of dynamic load loading experiments, the digital imaging device acquires first image information during the experiment, and acquires second image information during the experiment after the leak-proof plate of the servo pressure experiment device is opened; The digital imaging device obtains the critical leakage amount corresponding to the servo pressure testing device according to multiple groups of the first image information and the corresponding second image information.

3. The method for determining tunnel leakage according to claim 2, characterized in that: The applied information includes the soil pore pressure of the soil body and the corresponding current through-slit size of the servo pressure test device under each set of dynamic load loading tests; The data storage device obtains the relationship information between the pore pressure of the soil and the crack threshold value according to the multiple sets of the applied information and the corresponding leakage information, specifically including: The data storage device determines the corresponding crack threshold of the servo pressure test device according to the multiple groups of soil pore pressures, the current crack size and the corresponding critical leakage amount; The data storage device obtains the relationship information between the pore pressure and the through-fracture threshold of the soil body according to the multiple groups of pore pressures and the corresponding through-fracture thresholds.

4. The method for determining tunnel leakage according to any one of claims 1 to 3, characterized in that: The predicted results include tunnel remediation and normal tunnel operation; The step of predicting leakage of the target tunnel according to the relationship information to obtain a prediction result specifically includes: Obtain the target crack size and target pore pressure when cracks appear in the target tunnel; Determining a target crack-through threshold of the target tunnel according to the relationship information and the target pore pressure; If the difference between the target through-slot size and the target through-slot threshold is less than a preset value, determining that the prediction result is tunnel remediation; If the difference between the target through-slot size and the target through-slot threshold is greater than or equal to the preset value, it is determined that the prediction result is normal operation of the tunnel.

5. A tunnel leakage test system for implementing the tunnel leakage determination method according to any one of claims 1 to 4, characterized in that: The tunnel leakage test system comprises a servo pressure test device, a digital image device and a data storage device, wherein soil is contained in the servo pressure test device; The servo pressure test device is used to perform multiple groups of dynamic load loading tests on the soil to obtain application information under each group of dynamic load loading tests, wherein the sizes of the through cracks corresponding to each group of dynamic load loading are different; The digital imaging device is used to collect leakage information of each group of dynamic load loading experiments performed by the servo pressure test device; The data storage device is used to obtain the relationship information between the pore pressure of the soil and the crack threshold value according to multiple groups of the applied information and the corresponding leakage information, and predict the leakage of the target tunnel according to the relationship information to obtain the prediction result; wherein the crack threshold value is the size of the crack at which the soil collapses under the pore pressure.

6. The tunnel leakage test system according to claim 5, characterized in that: The servo pressure test device comprises a servo press and a compression box, wherein the compression box contains saturated soil, and the servo press is used to provide dynamic loads of different magnitudes and frequencies to the soil; The servo press is provided with a force plate, the lower part of the compression box is connected to a bottom plate, the force plate and the bottom plate are connected via a rubber membrane, so that a sealed environment is formed between the force plate and the compression box, and the force plate moves in the compression box to apply a dynamic load to the soil.

7. The tunnel leakage test system according to claim 6, characterized in that: The bottom plate is connected to leakage plates with different sizes of through-slots, an open groove is provided on the bottom plate, the leakage plate is arranged opposite to the open groove, each group of dynamic load loading experiments corresponds to the leakage plates with different sizes of through-slots, so that the soil after the dynamic load loading experiment leaks through the leakage plates; the bottom plate is also connected to a leakage-stopping plate corresponding to the through-slots of the leakage plate, and the leakage-stopping plate is connected to the leakage plate in the dynamic load loading experiment.

8. The tunnel leakage test system according to claim 7, characterized in that: The leakage plate is provided with a waterproof rubber ring, and the leakage plate is connected to the bottom plate through the waterproof rubber ring; the leakage-stopping plate includes a four-corner frame and a clamping plate connected to each other, and the four-corner frame is fixedly connected to the outside of the bottom plate.

9. The tunnel leakage test system according to claim 8, characterized in that: The compression box is made of an acrylic plate, and the bottom plate and the quadrilateral frame are made of stainless steel.

10. The tunnel leakage test system according to claim 6, characterized in that: The force-applying plate is provided with a plurality of connecting plates, the upper portion of the compression box is provided with a connecting hoop, one end of the rubber membrane is fixedly connected to the plurality of connecting plates, and the other end of the rubber membrane is fixedly connected to the connecting hoop.

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