Testing device and method for simulating dynamic water condition composite stratum tunnel grouting

Abstract

The invention relates to the technical field of grouting simulation tests, in particular to a test device and method for simulating dynamic water condition composite stratum tunnel grouting, and the test device for simulating dynamic water condition composite stratum tunnel grouting comprises a model box, a water storage tank, a single-ring duct piece, a dynamic water simulation system, a grouting system and a data acquisition and analysis system; the model box is filled with a permeable medium, the single-ring duct piece is arranged in the permeable medium, the grouting system is connected with the single-ring duct piece, and grouting slurry is colored; the dynamic water simulation system comprises a water supply system and a drainage system, the data acquisition and analysis system is arranged on one side of the model box and used for acquiring and analyzing the state of grouting slurry in the model box, and the problem that grouting and seepage conditions of different seepage fields cannot be visually observed and simulated in a traditional grouting test is solved. The seepage field grouting simulation test is simplified, and the seepage field grouting effect in the pore stratum cannot be effectively researched.

Description

Technical Field

[0001] The invention relates to the technical field of grouting simulation test, and in particular to a test device and method for simulating grouting of a composite stratum tunnel under dynamic water conditions. Background Art

[0002] During construction or operation, underground structures often face the problem of water infiltration from the surface or strata into the structure, resulting in water leakage inside the underground structure. The water leakage of underground engineering structures such as subways not only destroys the dynamic balance of the seepage field of the surrounding strata, but also aggravates the water leakage problem of the structure itself, posing a serious threat to the safety and stability of underground engineering. Especially in the tunnel engineering of the Linjiang Linshui section, due to the proximity to the water body, the groundwater pressure is relatively high, and the strata are often loose due to long-term influence of factors such as water flow scouring. If there are cracks or cavities around the tunnel, river water may enter the tunnel along these channels, seriously affecting the normal use of the tunnel and the safety of the structure. Although the tunnel of the Beijiang Beishui section does not directly face the river water pressure like the Linjiang section, if the strata are composed of softer clay or silty clay, their bearing capacity is limited, and the influence of groundwater is still significant, which may lead to unstable strata.

[0003] In order to study the application effect of grouting reinforcement technology in underground engineering, model test has become an important means. Model test can directly reflect the diffusion behavior of slurry and is one of the important ways to study the diffusion mechanism of grouting. However, there are still many shortcomings in the dynamic water grouting model test device in the prior art. For example, many devices need to constantly bring water from the outside into the model box to create dynamic water conditions, which leads to a long test time and a single simulated grouting condition. In addition, the dynamic water simulation system of the existing device can only simulate one seepage field grouting condition, and cannot simulate different seepage field grouting conditions, resulting in a single seepage field grouting simulation test. Furthermore, the data acquisition system of the existing device mostly records the grouting slurry diffusion process through the front and rear cameras, and cannot effectively and intuitively observe the slurry diffusion law in the grouting area inside the model box. Summary of the invention

[0004] One of the purposes of the present invention is to provide a test device for grouting in a composite stratum tunnel simulating dynamic water conditions, so as to solve the problem that traditional grouting tests cannot intuitively simulate grouting in different seepage fields and their seepage conditions, resulting in the singleness of the seepage field grouting simulation test and the inability to effectively study the seepage field grouting effect in porous strata; the second purpose is to propose an experimental method for grouting in a composite stratum tunnel simulating dynamic water conditions.

[0005] In order to achieve the above object, on the one hand, the technical solution adopted by the present invention is as follows: A test device for grouting a composite stratum tunnel under simulated dynamic water conditions, comprising a model box, a water storage tank, a single-ring segment, a dynamic water simulation system, a grouting system and a data acquisition and analysis system; The model box is filled with a permeable medium, the single-ring segment is arranged in the permeable medium, the grouting system is connected to the single-ring segment and is used to inject grouting slurry into the model box, and the grouting slurry is colored; the permeable medium is round cake-shaped glass particles, which are transparent structures and are used to simulate composite formations; The dynamic water simulation system includes a water supply system and a drainage system. The water supply system is connected to the model box and the water storage tank respectively, and is used to extract the water flow in the water storage tank to the model box; the drainage system is connected to the model box and the water storage tank respectively, and is used to extract the water flow of the seepage in the model box to the water storage tank to form a dynamic water cycle; The data acquisition and analysis system is arranged on one side of the model box and is used for acquiring and analyzing the state of the grouting slurry in the model box.

[0006] Furthermore, it also includes a water inlet partition and a water outlet partition, the water inlet partition and the water outlet partition are respectively arranged on both sides of the model box, the model box is connected to the water inlet partition and the water outlet partition through a plurality of water heads, and each of the water heads is evenly arranged along the height direction of the model box; A water-permeable membrane is provided on one side of the model box close to the water outlet partition groove, and the water-permeable membrane is detachable.

[0007] Further, the water supply system includes a water supply container, a water supply pipe and a water supply unit, the water supply container and the water inlet compartment are connected through the water supply pipe, the water supply pipe is arranged at the bottom of the water supply container and the water inlet compartment, and the water supply pipe is provided with a water supply valve and a flow sensor; The water supply unit includes an electric water supply pump, an electric water supply pump and a water supply air compressor. One end of the electric water supply pump is connected to the water tank, and the other end of the electric water supply pump is connected to the water supply container. The water supply air compressor is used to pressurize the water supply container.

[0008] Further, the drainage system comprises a drainage electric pumping pipe and a drainage electric pumping pump, and the drainage electric pumping pump is arranged on the drainage electric pumping pipe; One end of the drainage electric water pumping pipe extends into the bottom of the water outlet partition groove, and the other end of the drainage electric water pumping pipe is connected to the water storage tank.

[0009] Furthermore, the single-ring segment is installed in the model box, and a plurality of grouting holes are symmetrically arranged in the single-ring segment; The number of the grouting systems is one or more, and each of the grouting systems is connected to one of the grouting holes.

[0010] Furthermore, the grouting system comprises a grouting air compressor, a grouting bucket and a grouting pipe. The grouting air compressor is used to increase the pressure of the grouting bucket, and the grouting pipe is provided with a flow rate regulating valve.

[0011] Furthermore, the model box and the water storage tank are transparent structures; A marking grid, a main coordinate axis and a sub-coordinate axis are provided on one side of the model box, and the marking grid, the main coordinate axis and the sub-coordinate axis are all colored; The marking grid has a fixed width in both horizontal and vertical directions, forming a certain number of square grids; The origin of the main coordinate axis is located at the position where the center of the ring of the single-ring segment is projected onto the model box, and the origin of each sub-coordinate axis is located at the position where the corresponding grouting hole is projected onto the model box.

[0012] Furthermore, the data acquisition and analysis system includes a matte black plastic plate, a high-speed camera, a data transfer line, an image acquisition card and a computer terminal, the high-speed camera and the computer terminal are connected via the data transfer line, and the data transfer line is connected to the image acquisition card; The matte black plastic plate is provided with a plurality of barb components, and the matte black plastic plate is suspended on the model box through the barb components. The surface of the matte black plastic plate is rough, and diffuse reflection occurs when light is irradiated to the surface of the matte black plastic plate to reduce the intensity of reflection and refraction.

[0013] On the other hand, the present application also proposes a test method for simulating dynamic water conditions composite stratum tunnel grouting, comprising using the test device for simulating dynamic water conditions composite stratum tunnel grouting as described above, and also comprising the following steps: S1: Construct the system assembly structure; fill the model box with the permeable medium, and set the marking grid, main coordinate axis and sub-coordinate axis on the model box; S2: Start the dynamic water simulation system; control the water level of the water inlet and outlet troughs by controlling the water supply system and drainage system to form a stable seepage field; S3: Start the grouting system; grouting is performed into the model box according to the set grouting pressure and injection rate; in the grouting system, a plurality of grouting holes are arranged on a single ring segment and are symmetrically distributed, so as to realize single-hole, multi-hole and pressure relief drainage grouting, thereby simulating grouting methods under different working conditions; The grouting methods include grouting method 1, grouting method 2 and grouting method 3; Among them, grouting method one is round glass particles, dynamic water grouting and single hole grouting; Grouting method two is round glass particles, dynamic water grouting and porous grouting; Grouting method three is round glass particles, dynamic water grouting and pressure relief drainage grouting; S4: Start the data acquisition and analysis system; record the diffusion process of the grouting slurry through a high-speed camera, and use a computer terminal to process the data to analyze the diffusion area, maximum diffusion radius and diffusion direction of the grouting slurry; S5: Clean the medium material; after completing the test, clean the permeable medium and replace the single-ring segments for recycling.

[0014] Furthermore, in step S2, the following steps are included: S21: injecting water into the water storage tank, and pumping water from the water storage tank into the water supply container through the water supply electric pump; S22: Use a water supply air compressor to pressurize the water supply container, open the water supply valve, and fill water into the water inlet compartment through the water supply pipe to a predetermined height; S23: Control the dynamic water to enter the model box until the entire grouting area of ​​the model box is filled and finally flows into the water outlet partition groove; S24: water is poured into one side of the water inlet partition by a water supply electric pump, and water is pumped out from one side of the water outlet partition by a drainage electric pump, so as to realize the circulation of dynamic water between the water inlet partition and the water outlet partition, thereby forming a stable seepage field; S25: By controlling the water level height of the inlet and outlet baffles and utilizing the head difference to control the hydraulic gradient, different seepage field conditions can be simulated.

[0015] Beneficial effects of the present invention: The present application is used to simulate the grouting process of a composite stratum tunnel under dynamic water conditions and to intuitively analyze the slurry diffusion behavior. The grouting system can be used to simulate the diffusion process of the grouting slurry and the dynamic water simulation system can be used to simulate the grouting under a dynamic water environment, thereby simulating the real grouting application environment and providing a basis for establishing mathematical models and proposing new grouting theories.

[0016] This application uses a model box as a transparent structure to observe the diffusion law of the infiltration grouting process in real time and intuitively, realize the visualization of the grouting process, and facilitate the observation of the slurry diffusion law in the grouting area inside the model box.

[0017] The permeable medium of the present application adopts grouting round cake-shaped glass particles. Through its transparency, the diffusion of grouting slurry can be directly observed, and through its recyclability, it can be recycled to simulate different grouting conditions.

[0018] The single-ring segment of the present application can realize single-hole and multi-hole grouting, as well as pressure relief drainage grouting and other specific working conditions through bolts, and can simulate the grouting conditions of multiple seepage fields, and has a wide range of applications.

[0019] The matte black plastic plate of the present application is arranged on the outside of the back of the model box, and its surface microstructure is relatively rough. When light hits the surface, diffuse reflection occurs, which can greatly reduce the intensity of reflection and refraction, thereby ensuring the quality of the slurry diffusion photos taken.

[0020] The water-permeable membrane of the present application is a detachable water-permeable membrane. After each simulation of a working condition in the test, the grouting is stopped and the water-permeable membranes on the left and right sides can be pulled out to clean the round glass particles. After cleaning, the round glass particles are refilled into the model box for a second test, thereby realizing recycling.

[0021] The present application can quantitatively and intuitively analyze the area, maximum diffusion radius, diffusion direction and maximum distance of the two-dimensional grouting slurry diffusion range under dynamic water conditions through the transparent characteristics of round glass particles, the setting of a marking grid on the front glass plate of the model box, the intuitive characteristics of the main coordinate axis and the sub-coordinate axis, and the quantitative characteristics of mathematical processing of computer terminal images, and can effectively study the grouting effect of the seepage field in porous formations.

[0022] Other advantages, objectives and features of the present application will be described to some extent in the subsequent description, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present application. The objectives and other advantages of the present application can be achieved and obtained through the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front view schematic diagram of the test device for grouting a composite stratum tunnel under simulated dynamic water conditions of the present invention; Figure 2 It is a structural schematic diagram of a single ring segment of a test device for grouting a composite stratum tunnel under simulated dynamic water conditions according to the present invention; Figure 3 A schematic diagram of the structure of the dynamic water simulation system for installing the test device for simulating dynamic water conditions for composite stratum tunnel grouting according to the present invention; Figure 4 A schematic diagram of the data acquisition and analysis system structure of the test device for simulating dynamic water conditions composite stratum tunnel grouting of the present invention; Figure 5 It is a front schematic diagram of a model box of a test device for simulating composite stratum tunnel grouting under dynamic water conditions of the present invention; Figure 6 It is a schematic diagram of the back side of the model box of the test device for simulating dynamic water conditions composite stratum tunnel grouting of the present invention; Figure 7 It is a schematic diagram of the dynamic water circulation of the test device for simulating dynamic water conditions for composite stratum tunnel grouting of the present invention; Figure 8A schematic diagram of a matte black plastic plate in a test device for simulating composite stratum tunnel grouting under dynamic water conditions of the present invention; Fig. 9 A schematic diagram of a single-hole grouting segment with bolts of a test device for grouting a composite stratum tunnel under simulated dynamic water conditions according to the present invention; Fig.10 It is a schematic diagram of a multi-hole grouting segment with bolts of a test device for grouting a composite stratum tunnel under simulated dynamic water conditions of the present invention; Fig.11 It is a schematic diagram of the pressure relief drainage grouting pipe segment with bolts of the test device for grouting in composite stratum tunnel simulating dynamic water conditions of the present invention; Fig.12 It is a schematic diagram of seepage balance of the test method for grouting a composite stratum tunnel under simulated dynamic water conditions of the present invention.

[0024] Among them, the model box 1, the single-ring segment 2, the round glass particles 3, the water inlet partition 4, the water supply container 5, the water supply air compressor 6, the water supply electric pumping pipe 7, the water storage tank 8, the water supply valve 9, the flow sensor 10, the cushion block 11, the grouting pipe 12, the flow rate regulating valve 13, the grouting bucket 14, the grouting air compressor 15, the drainage electric pumping pipe 16, the water outlet partition 17, the marking grid 18, the matte black plastic plate 19, the grouting hole 20, the bolt 21, the flexible ethylene geomembrane 22, the high-speed camera 23, the data adapter cable 24, the image acquisition card 25, the computer terminal 26, and the water supply pipe 27. DETAILED DESCRIPTION

[0025] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0026] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0027] This embodiment proposes a test device for simulating composite stratum tunnel grouting under dynamic water conditions. Figures 1 to 12 As shown, it includes a model box 1, a water storage tank 8, a single-ring segment 2, a dynamic water simulation system, a grouting system and a data acquisition and analysis system.

[0028] The model box 1 is filled with a permeable medium, and the single-ring segment 2 is arranged in the permeable medium in the model box 1. The permeable medium material of the present application is preferably round cake-shaped glass particles 3, which are used to simulate sand and soil. The particle size is determined according to the equivalent diameter of the sand and soil in the local stratum. For example, the equivalent diameter can be flexibly processed by using different strata to simulate composite strata such as upper fine sand, middle coarse sand and lower gravel strata. The round cake-shaped glass particles 3 are transparent structures, and the diffusion of the grouting slurry can be directly observed through their transparency. They can also be recycled to simulate different grouting conditions through their recyclability. The diameter of the single-ring segment 2 is determined according to the scaling ratio of the shield segment model in the project.

[0029] The round glass particles 3 can be designed with different diameters to be equivalent to different strata, so as to simulate composite strata such as upper fine sand, middle coarse sand and lower gravel strata.

[0030] The grouting system is connected to the single-ring segment 2 and is used to inject grouting slurry into the model box 1. The grouting slurry has color. The dynamic water simulation system includes a water supply system and a drainage system. The water supply system is connected to the model box 1 and the water storage tank 8 respectively, and is used to extract the water flow in the water storage tank 8 to the model box 1; the drainage system is connected to the model box 1 and the water storage tank 8 respectively, and is used to extract the water flow of the seepage in the model box 1 to the water storage tank 8 to form a dynamic water cycle; The data acquisition and analysis system is arranged on one side of the model box 1 and is used to acquire and analyze the state of the grouting slurry in the model box 1 .

[0031] The model box 1 also includes a water inlet partition 4 and a water outlet partition 17, which are respectively arranged on both sides of the model box 1. The model box 1 is connected with the water inlet partition 4 and the water outlet partition 17 through a plurality of water heads, and each water head is evenly arranged along the height direction of the model box 1; the water inlet partition 4 and the water outlet partition 17 are both provided with scales, so as to facilitate observation of the water level height in the water inlet partition 4 and the water outlet partition 17, and different water head differences on the left and right sides can be formed by controlling the water level height of the water inlet partition 4 and the water outlet partition 17.

[0032] In this embodiment, the model box 1 is arranged above the water storage tank 8, and the model box 1 is supported by arranging a cushion block 11, which is arranged at the bottom of the model box 1. The cushion block 11 divides the water storage tank 8 into three spaces, including a drainage space, a flow space, and a water supply space arranged from left to right. A circular tubular hollow hole is designed in the center of the cushion block 11, and the circular tubular hollow hole connects the drainage space, the flow space, and the water supply space, so that water can flow in the water storage tank 8.

[0033] A permeable membrane is pasted on one side of the model box 1 close to the water outlet partition 17. The function of the permeable membrane is to ensure that the moving water passes through while the grouting slurry in the model box 1 does not pass through, so as to realize the recycling of moving water and avoid blockage during circulation. This dynamic water simulation system adjusts the left and right liquid levels by controlling the water head difference through the water inlet partition 4 and the water outlet partition 17. After the pumping process, the water levels of the water inlet partition 4 and the water outlet partition 17 can reach their respective predetermined heights. After stabilization for a certain period of time, seepage balance can be achieved.

[0034] As a preferred embodiment, the water supply system includes a water supply container 5, a water supply pipe 27 and a water supply unit. The water supply container 5 is connected to the water inlet compartment 4 through the water supply pipe 27. The water supply pipe 27 is arranged at the bottom of the water supply container 5 and the water inlet compartment 4. The water supply pipe 27 is provided with a water supply valve 9 and a flow sensor 10. The water supply unit includes an electric water supply pumping pipe 7, an electric water supply pump and an air compressor 6. One end of the electric water supply pumping pipe 7 is connected to the water tank 8, and the other end of the electric water supply pumping pipe 7 is connected to the water supply container 5. The air compressor 6 is used to pressurize the water supply container 5.

[0035] According to the above technical scheme, when it is necessary to start the water supply system, the water supply electric pump starts working, and the water in the water storage tank 8 is pumped into the water supply container 5 through the water supply electric pump pipe 7. The water supply pipe 27 is arranged at the bottom of the water supply container 5 and the water inlet partition 4, ensuring that water can flow into the water inlet partition 4 evenly and stably. A water supply valve 9 and a flow sensor 10 are arranged on the water supply pipe 27. The water supply valve 9 is used to control the flow of water, and the flow sensor 10 monitors and feeds back the water flow information in real time to ensure precise control of the water supply process; by arranging a water supply air compressor 6 to increase the pressure in the water supply container 5, it is ensured that the water can have sufficient pressure to flow into the water inlet partition 4, and form a stable dynamic water circulation in the model box 1. The water supply container 5 can store and provide a stable water flow, ensuring a continuous supply of dynamic water during the test and avoiding poor or interrupted water supply due to insufficient pressure. In the test simulating dynamic water conditions, a stable water flow is essential for forming a stable seepage field, and the pressurized water can spontaneously flow into the water inlet partition 4 and the model box 1 faster, thereby shortening the test preparation time and improving the overall water supply efficiency. It is helpful to simulate the grouting process under different seepage field conditions and provide stronger support for the research on grouting reinforcement technology in underground engineering.

[0036] As a preferred embodiment, the drainage system includes a drainage electric pumping pipe 16 and a drainage electric pumping pump. The drainage electric pumping pump is arranged on the drainage electric pumping pipe 16; one end of the drainage electric pumping pipe 16 extends into the bottom of the water outlet compartment 17, and the other end of the drainage electric pumping pipe 16 is connected to the water storage tank 8. One end of the drainage electric pumping pipe 16 extends into the bottom of the water outlet compartment 17 to ensure that the accumulated water in the simulation test can be thoroughly and efficiently discharged, and the accumulated water can be prevented from interfering with the test results. The drainage electric pumping pump is arranged on the drainage electric pumping pipe 16. Through its powerful suction capacity, the accumulated water in the water outlet compartment 17 is quickly pumped into the water storage tank 8, which provides convenience for subsequent tests or treatments; the entire drainage system is not only easy to operate, but also can significantly improve the efficiency and accuracy of the test, and provides strong support for tests such as tunnel grouting in composite strata simulating dynamic water conditions.

[0037] As a preferred embodiment, a single-ring segment 2 is installed in the model box 1, and a plurality of grouting holes 20 are symmetrically arranged in the single-ring segment 2; a seal is provided at each grouting hole 20, and the seal of this embodiment adopts a bolt 21, and the inner surface of the grouting hole 20 is provided with a thread. The grouting hole 20 can be blocked or opened according to specific working conditions to simulate single-hole grouting, multi-hole grouting, pressure relief drainage grouting and other working conditions.

[0038] The water supply system and the drainage system can form a left and right water head difference. The left and right water head difference is controlled to analyze the influence of dynamic water on the diffusion of grouting slurry in different seepage fields. In the grouting system, a plurality of grouting holes 20 are arranged on the single-ring segment 2 and are symmetrically distributed, so that single-hole, multi-hole and pressure-relief drainage grouting can be realized, thereby simulating grouting under different working conditions. The grouting slurry is colored with enhanced pigments (red or yellow), and the selection of enhanced pigments is determined according to different working conditions, so as to clearly analyze the flow path and diffusion process of the grouting slurry in different seepage fields of the composite formation.

[0039] Furthermore, the surface of the bolt 21 is covered with a flexible vinyl geomembrane 22, which plays a role in waterproofing and preventing slurry leakage. Of course, it is understandable that the sealing member is not limited to the above-mentioned bolt 21 plugging, and structures such as rubber plugs and clips can also be used as long as the grouting hole 20 can be detachably plugged.

[0040] The number of grouting systems is one or more, and each grouting system is connected to one of its grouting holes 20. By setting a plurality of grouting holes 20 on the single-ring segment 2 installed in the model box 1, the grouting process is more flexible and efficient. Each grouting hole 20 can be connected through an independent grouting system. When conducting a simulation test, the synchronous grouting operation of multiple grouting holes 20 can be realized, thereby simulating complex working conditions under multiple grouting conditions at the same time. The number of grouting systems can be flexibly configured according to actual needs. It can be a single grouting system focusing on the precise control of a single grouting hole 20, or multiple grouting systems working in parallel to jointly cope with complex grouting tasks. This design not only improves the flexibility and accuracy of the test, but also helps researchers to have a deeper understanding of the interaction mechanism in the grouting process, and provides valuable experimental data support for the optimization of the grouting reinforcement process of underground engineering; at the same time, the design of multiple grouting holes 20 also enhances the practicality and application value of the simulation test.

[0041] As a preferred embodiment, the grouting system includes a grouting air compressor 15, a grouting bucket 14 and a grouting pipe 12. The grouting air compressor 15 is used to increase the pressure in the grouting bucket 14. Its function is to control the grouting pressure of the grouting system, so as to facilitate the simulation of the influence of different grouting pressures on the penetration and diffusion of the grouting slurry of the single-tube ring segment. A flow rate regulating valve 13 is arranged on the grouting pipe 12. When the grouting system is working, the grouting air compressor 15 increases the pressure in the grouting bucket 14, and pushes the grouting slurry to flow to the grouting hole 20 of the single-ring segment 2 through the grouting pipe 12; the flow rate regulating valve 13 arranged on the grouting pipe 12 can accurately control the flow rate of the grouting slurry, ensure the stability and controllability of the grouting process, not only improve the grouting efficiency, but also enable researchers to flexibly adjust the grouting parameters according to different working conditions, and conduct in-depth research on the penetration and solidification mechanism of the grouting slurry in complex strata, which provides strong support for the optimization of grouting reinforcement technology for underground engineering.

[0042] Specifically, the grouting slurry of the present application includes cement slurry, cement-water glass double liquid slurry and ultrafine cement slurry, which can be used to simulate the dynamic water grouting simulation of different types of grouting slurries; the grouting slurry is colored with fortified pigments (red or yellow), and the selection of fortified pigments is determined according to different working conditions, so as to clearly analyze the flow path and diffusion process of the slurry in different seepage fields of the composite formation.

[0043] As a preferred embodiment, Figure 4 and Figure 5As shown, the model box 1 and the water storage tank 8 are transparent structures; the front of the model box 1 is provided with a marking grid 18, a main coordinate axis and a sub-coordinate axis, and the marking grid 18, the main coordinate axis and the sub-coordinate axis are all colored, and the marking grid 18, the main coordinate axis and the sub-coordinate axis are marked with green colors, which are convenient for distinguishing from the color of the grouting slurry, so as to more conveniently and clearly observe the diffusion process of the grouting slurry; the origin of the main coordinate axis is located at the position where the center of the ring of the single-ring segment 2 is projected to the model box 1, and the origin of each sub-coordinate axis is located at the position where the corresponding grouting hole 20 is projected to the model box 1. The model box 1 and the water storage tank 8 of this embodiment adopt a transparent structure design, which is convenient for real-time observation of the internal test process and results. The front of the model box 1 is provided with a marking grid 18, a main coordinate axis and a sub-coordinate axis, and they are all colored, which enhances visualization and positioning accuracy. The origin of the main coordinate axis is aligned with the projection of the center of the single-ring segment 2. The main coordinate axis can observe the direction, maximum distance and maximum diffusion radius of the grouting slurry diffusion range at the middle grouting hole 20; the origin of each sub-coordinate axis corresponds to the projection position of the grouting hole 20, and can observe the direction, maximum distance and maximum diffusion radius of the grouting slurry diffusion range at the grouting hole 20. This layout not only simplifies data recording and analysis, but also greatly improves the convenience of test operation and the accuracy of test results, providing researchers with an intuitive and efficient test environment.

[0044] Furthermore, the horizontal and vertical widths of the marking grid 18 are fixed to be equal, forming a certain number of square grids; taking a square grid as a unit, the number of grids covered by the grouting slurry can be used to roughly estimate the direction and distance of the grouting slurry diffusion range, and obtain the displacement field of the grouting slurry during the dynamic diffusion process. In particular, if the grouting slurry covers more than half of the grid but not all of the grids, it is recorded as 0.5 grids, and if the grouting slurry covers less than half of the grid, no grid number is recorded.

[0045] As a preferred embodiment, Figure 4 and Figure 6As shown, the data acquisition and analysis system includes a matte black plastic plate 19, a high-speed camera 23, a data transfer line 24, an image acquisition card 25 and a computer terminal 26. The high-speed camera 23 and the computer terminal 26 are connected via the data transfer line 24, and the image acquisition card 25 is connected to the data transfer line 24. A plurality of barb components (not shown) are provided on the matte black plastic plate 19, and the matte black plastic plate 19 is suspended on the back of the model box 1 through the various barb components for easy disassembly. The data acquisition and analysis system of the present application efficiently completes the dynamic recording and analysis of the diffusion of grouting slurry by integrating matte black plastic plate 19, high-speed camera 23, data transfer line 24, image acquisition card 25 and computer terminal 26; when the system is working, the surface microstructure of matte black plastic plate 19 is relatively rough. Matte black plastic plate 19 is used as a shooting background. The rough surface microstructure effectively reduces the concentrated reflection under the irradiation of light, produces a diffuse reflection effect, and greatly reduces the reflection and refraction intensity, ensuring the quality of the slurry diffusion photos obtained by shooting, avoiding image distortion or light spot interference that may be caused by the smooth surface, and improving the accuracy and reliability of the data. The high-speed camera 23 is closely connected to the computer terminal 26 through the data transfer line 24, and the image acquisition card 25 is connected in the middle to achieve high-speed, high-quality image capture and transmission, which not only ensures the real-time recording of the slurry diffusion process, but also facilitates subsequent data processing and analysis. The matte black plastic plate 19 is conveniently hung on the back of the model box 1 through the barb component, which is both stable and easy to disassemble, providing great flexibility for experimental setting and adjustment.

[0046] The high-speed camera 23 uses photographic imaging technology combined with the marking grid 18 to accurately capture the diffusion range of the slurry at different grouting time nodes, and uploads it to the computer terminal 26 through the image acquisition card 25 for image mathematical data processing, and then the diffusion area, maximum diffusion radius, diffusion direction and maximum distance of the grouting slurry can be analyzed through mathematical methods.

[0047] On the other hand, the present application also proposes a test method for simulating dynamic water conditions composite stratum tunnel grouting, comprising using the test device for simulating dynamic water conditions composite stratum tunnel grouting as described above, and also comprising the following steps: S1: constructing a system assembly structure; filling the model box 1 with a permeable medium, and setting a marking grid 18, a main coordinate axis and a sub-coordinate axis on the model box 1; Place two cushion blocks 11 at appropriate positions at the bottom of the water storage tank 8 , and then place the model box 1 on the cushion blocks 11 .

[0048] A water-permeable membrane is pasted on the side wall of the model box 1 to ensure that moving water passes through the water-permeable membrane while grouting slurry does not pass through; a water inlet partition 4 and a water outlet partition 17 are arranged on both sides of the model box 1.

[0049] The round cake-shaped glass particles 3 are screened into different particle sizes by screening, and three filling materials are screened out, namely, equivalent fine sand material, equivalent coarse sand material and equivalent gravel material, so as to simulate the composite formation.

[0050] The three filling materials are filled into the model box 1 according to the lower gravel material, the middle coarse sand material and the upper fine sand material; when the lower equivalent gravel material is filled, the single ring segment 2 is placed into the model box 1, and then other filling materials are filled.

[0051] Graduation lines are drawn at a fixed distance on the side of the water inlet compartment 4 and the water outlet compartment 17 near the round glass particles 3 to facilitate the control of the water level height in the water inlet compartment 4 and the water outlet compartment 17; Figure 4 As shown, a corresponding marking grid 18 and coordinate axes (including a main coordinate axis and a sub-coordinate axis) are set on the front glass plate of the model box 1, and their colors are set to green marks to distinguish them from the color of the grouting slurry, so as to more conveniently and clearly observe the diffusion process of the grouting slurry.

[0052] S2: Start the dynamic water simulation system; control the water level of the water inlet compartment 4 and the water outlet compartment 17 by controlling the water supply system and the drainage system to form a stable seepage field; First, inject a certain amount of water into the water tank 8, and pump water from the water tank 8 into the water supply container 5 through the water supply electric water pump; pour a certain amount of water into the water tank 8 from the outside, turn on the water supply electric water pump to pump part of the water in the water tank 8 into the water supply container 5.

[0053] Use the water supply air compressor 6 to pressurize the water supply container 5. After the pressurization is completed, turn off the water supply air compressor 6, open the water supply valve 9, and fill the water inlet compartment 4 with water to a predetermined height through the water supply pipe 27; The dynamic water is controlled to enter the model box 1 until the entire grouting area of ​​the model box 1 is filled, and finally flows into the outlet partition 17; the dynamic water passes through the water inlet partition 4, the permeable membrane, the permeable medium and the single-ring segment 2, fills the entire grouting area of ​​the model box 1, and finally enters the outlet partition 17. After a certain period of time, the dynamic water reaches a certain height in the outlet partition 17, and the drainage electric pump is turned on to pump water.

[0054] The water supply electric pump is used to fill water on one side of the water inlet partition 4, and the drainage electric pump is used to pump water on one side of the water outlet partition 17, so as to realize the circulation of dynamic water between the water inlet partition 4 and the water outlet partition 17, thereby forming a stable seepage field; By controlling the water level heights of the water inlet partition 4 and the water outlet partition 17 and utilizing the head difference to control the hydraulic gradient, different seepage field conditions are simulated; the water supply electric pump fills water on one side of the water inlet partition 4, and the drainage electric pump pumps water on one side of the water outlet partition 17. At this time, it is in the pumping and filling process. After a certain period of pumping and filling, the water level of the water inlet partition 4 reaches a predetermined height, and the water level of the water outlet partition 17 reaches a predetermined height.

[0055] After a certain period of stabilization, the seepage equilibrium is reached and a stable seepage field is formed.

[0056] like Fig.12 As shown in Figure 2, different seepage fields are specifically expressed by the hydraulic gradient through the head difference formula, which is as follows: ;

[0057] Wherein: i is hydraulic gradient; H1 is the water level height of the water inlet compartment 4; H2 is the water level height of the water outlet compartment 17; L is the water flow length. The dynamic water simulation system of the present invention can achieve simulation of different seepage fields by pressurizing the water supply container 5 and setting different water head differences to control the hydraulic gradient.

[0058] During the water injection process, the moving water passes through the water supply container 5, the water supply pipe 27, the water inlet partition 4, the model box 1, the water outlet partition 17, the drainage electric pumping pipe 16 and the water storage tank 8 in turn, and finally the water in the water storage tank 8 is pumped into the water supply container 5 again through the water supply electric pump, thereby realizing the recycling of the moving water.

[0059] S3: Start the grouting system; grouting is performed into the model box 1 according to the set grouting pressure and injection rate; Determine the required slurry fluid parameters in advance; In order to explore the influence of different grouting pressures on the penetration and diffusion of the outer-annular grouting slurry, combined with the grouting pressure values ​​of actual projects, the grouting pressure was set to three gradients of 0.3MPa, 0.4MPa and 0.5MPa, and the influence of the shield tunnel skylight period was considered, and only the diffusion law of the outer-annular grouting slurry within 2 hours was studied.

[0060] In order to explore the influence of different injection rates on the penetration and diffusion of the outer ring grouting slurry, as an example, the injection rates were set to 0.4m / s, 0.6m / s and 0.8m / s according to the actual grouting engineering parameters of Nanchang Metro, the grouting pressure was 0.5MPa, and the grouting time period of 30min-60min was intercepted to carry out comparative analysis of the slurry penetration and diffusion under different injection rates.

[0061] The test device can carry out flexible test arrangements according to the working conditions of the infiltration grouting project to meet the grouting environment similar to the project, and achieve a visual infiltration grouting effect to guide the actual project.

[0062] There are three types of grouting methods: Round glass particles, dynamic water grouting and single hole grouting; Round glass particles, dynamic water grouting and porous grouting; Round glass particles, dynamic water grouting and pressure relief drainage grouting; Grouting method 1; The grouting slurry configured according to the test requirements is injected into the grouting bucket 14 for mixing and storage, and then the grouting slurry is colored with a strengthening pigment (red).

[0063] The middle grouting hole 20 is opened on the single-ring segment 2 near the water inlet partition 4 by means of the bolt 21, and the remaining grouting holes 20 are closed (this embodiment studies single-hole grouting; since multiple grouting holes 20 are opened on the single-ring segment 2, only one grouting hole 20 in this embodiment needs to be opened, and the remaining grouting holes 20 are closed), and then the grouting pipe 12 is connected to the opened grouting hole 20.

[0064] Control the grouting air compressor 15, open the flow rate regulating valve 13, and start grouting at a relatively low pressure to allow the slurry to slowly enter the single-ring segment 2. As the grouting proceeds, observe the changes in grouting pressure and flow rate, and the pressure gradually increases. When the grouting volume reaches the design requirements or the pressure stabilizes for a certain period of time, stop grouting, use the data acquisition and analysis system to analyze and observe, and finally clean the equipment and pipelines in time.

[0065] Grouting method 2; Two grouting systems are prepared, in which one of the grouting systems injects the grouting slurry configured according to the test needs into the grouting bucket 14 for mixing and storage, and then uses the enhanced pigment (red) to color the grouting slurry; the other grouting system injects the grouting slurry configured according to the test needs into the grouting bucket 14 for mixing and storage, and then uses the enhanced pigment (yellow) to color the grouting slurry.

[0066] It should be noted that the difference between the two grouting systems lies in the different colors of the grouting slurries, which facilitates subsequent observation and recording of the grouting slurry diffusion process and facilitates the study and observation of the slurry diffusion law in the grouting area inside the model box 1.

[0067] like Figure 2 As shown, the upper and lower grouting holes 20 are opened by bolts 21 on one side of the single-ring segment 2 close to the water inlet partition 4, and the middle grouting hole 20 is closed. Then, one of the grouting pipes 12 is connected to the upper grouting hole 20, and the other grouting pipe 12 is connected to the lower grouting hole 20.

[0068] Adopt the interval grouting method, first grout the upper grouting hole 20, observe the pressure and flow changes, and then grout the lower grouting hole 20 after they stabilize, so as to avoid interference between adjacent holes. During the grouting process, monitor the parameter changes at the same time, and adjust the grouting pressure, flow and sequence in time according to the situation. When the grouting volume reaches the design requirements or the pressure is stable for a certain period of time, stop grouting and clean the equipment and pipelines in time.

[0069] It should be noted that the present application is limited to the above-mentioned setting of two grouting systems. In a possible implementation, the number of grouting systems can be three, four or more, and can be adaptively adjusted according to specific research needs to simulate multiple seepage field grouting conditions.

[0070] Grouting method three; The grouting slurry configured according to the test requirements is injected into the grouting bucket 14 for mixing and storage. The grouting slurry is then colored with a reinforced pigment (red).

[0071] The middle grouting hole 20 and the upper grouting hole 20 are opened on the single-ring segment 2 near the water inlet partition 4 by bolts 21, and the lower grouting hole 20 is closed, wherein the middle grouting hole 20 is used as a drainage hole, and then the grouting pipe 12 is connected to the upper grouting hole 20.

[0072] During the grouting process, attention should be paid to drainage and grouting pressure at the same time; when grouting begins, the pressure should be properly controlled. As grouting proceeds, observe the changes in drainage and grouting pressure of the drainage holes. When the drainage decreases and the grouting pressure increases to a certain level, it means that the pore water in the model box 1 is gradually discharged, and the grouting slurry begins to effectively fill the formation (round glass particles 3). At this time, the grouting pressure and grouting speed can be adjusted appropriately according to the situation. When the grouting volume reaches the design requirements or the pressure is stable for a certain period of time, stop grouting, use the data acquisition and analysis system for analysis and observation, and finally clean in time.

[0073] S4: Start the data acquisition and analysis system; record the grouting slurry diffusion process through the high-speed camera 23, and use the computer terminal 26 to process the data to analyze the grouting slurry diffusion area, maximum diffusion radius and diffusion direction; Before starting the grouting system, a matte black plastic plate 19 is arranged on the outside of the back of the model box 1 through two barb components, so that the intensity of reflection and refraction can be greatly reduced, thereby ensuring the quality of the slurry diffusion photos taken.

[0074] When one of the grouting conditions in step S3 is completed, observe the marking grid 18 designed on the front glass plate of the model box 1, and roughly estimate the slurry diffusion range by the number of grids covered by the grouting slurry to describe the displacement field during the dynamic diffusion of the slurry. The formula is as follows: ; Where: S is the total number of grids covered by the grouting slurry; S1 is the number of grids fully covered by the grouting slurry; S n represents a single edge grid that is not fully covered by the grouting slurry. If the grouting slurry covers more than half of the edge grid, S n =1. If the grouting slurry coverage does not exceed half of the edge grid, then S n Recorded as 0.

[0075] The maximum distance of the grouting slurry diffusion range can be further observed through the coordinate axis on the glass plate on the front of the model box, expressed as length, and the formula is as follows: ;

[0076] Where: L is the farthest distance of the slurry diffusion range; L1 is the distance of the farthest point in the slurry diffusion range perpendicular to the x-axis (horizontal direction); L2 is the distance of the farthest point in the slurry diffusion range perpendicular to the y-axis (vertical direction).

[0077] The maximum diffusion radius of the grouting slurry can be further observed through the coordinate axis on the front glass plate of the model box 1, expressed as an angle, and the formula is as follows: ;

[0078] Where: Maximum diffusion radius of grouting slurry; is the angle from the x-axis to the farthest boundary of the slurry diffusion range; It is the angle from the x-axis to the nearest boundary of the slurry diffusion range; in particular, the angle from the x-axis clockwise to the boundary of the slurry diffusion range is a positive angle, and the angle from the x-axis counterclockwise to the boundary of the slurry diffusion range is a negative angle.

[0079] The diffusion process of the grouting slurry in the model box 1 is recorded in real time by a high-speed camera 23 in front of the model, and the two-dimensional diffusion and condensation of the grouting slurry in the whole grouting process under different working conditions and dynamic water conditions, as well as the diffusion rate and diffusion form of the grouting slurry in different time periods of the diffusion process are recorded. The data information is transmitted to the image acquisition card 25 through the data adapter 24. The image acquisition card 25 is communicatively connected with the computer terminal 26. The computer terminal 26 performs image mathematical data processing on the captured information, and then the diffusion area, maximum diffusion radius and diffusion direction of the grouting slurry can be accurately analyzed through mathematical methods.

[0080] S5: Cleaning the medium material; after completing the test, clean the permeable medium and replace the single-ring segment 2 for recycling.

[0081] After each simulation of a working condition, the grouting is stopped and the permeable membranes on the left and right sides of the model box 1 are removed.

[0082] Continue to pump water to clean the round cake-shaped glass particles 3 until the round cake-shaped glass particles 3 are cleaned and transparent.

[0083] After cleaning, the clean and transparent round-shaped glass particles 3 and the single-ring tube segment 2 are taken out from the model box 1, and then the single-ring tube segment 2 is replaced.

[0084] The clean and transparent round-cake-shaped glass particles 3 are screened into different particle sizes again, and the newly screened round-cake-shaped glass particles 3 and the new single-ring segments 2 are refilled into the model box 1 for a second test, thereby realizing recycling.

[0085] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A test device for grouting composite strata tunnels simulating dynamic water conditions, characterized in that: include: Model box, water storage tank, single-ring segment, dynamic water simulation system, grouting system and data acquisition and analysis system; The model box is filled with a permeable medium, the single-ring segment is arranged in the permeable medium, the grouting system is connected to the single-ring segment and is used to inject grouting slurry into the model box, and the grouting slurry is colored; the permeable medium is round cake-shaped glass particles, and the round cake-shaped glass particles are transparent structures and are used to simulate composite formations; The dynamic water simulation system includes a water supply system and a drainage system. The water supply system is connected to the model box and the water storage tank respectively, and is used to extract the water flow in the water storage tank to the model box; the drainage system is connected to the model box and the water storage tank respectively, and is used to extract the water flow of the seepage in the model box to the water storage tank to form a dynamic water cycle; The data acquisition and analysis system is arranged on one side of the model box and is used for acquiring and analyzing the state of the grouting slurry in the model box.

2. The test device for simulating dynamic water conditions in composite stratum tunnel grouting according to claim 1 is characterized in that: It also includes a water inlet partition and a water outlet partition, the water inlet partition and the water outlet partition are respectively arranged on both sides of the model box, and a plurality of water heads are arranged between the model box and the water inlet partition and the water outlet partition, and each of the water heads is evenly arranged along the height direction of the model box; A water-permeable membrane is provided on one side of the model box close to the water outlet partition groove, and the water-permeable membrane is detachable.

3. The test device for simulating dynamic water conditions in composite stratum tunnel grouting according to claim 2 is characterized in that: The water supply system comprises a water supply container, a water supply pipe and a water supply unit. The water supply container is connected to the water inlet compartment through the water supply pipe. The water supply pipe is arranged at the bottom of the water supply container and the water inlet compartment. A water supply valve and a flow sensor are arranged on the water supply pipe. The water supply unit includes an electric water supply pump, an electric water supply pump and a water supply air compressor. One end of the electric water supply pump is connected to the water tank, and the other end of the electric water supply pump is connected to the water supply container. The water supply air compressor is used to pressurize the water supply container.

4. The test device for grouting composite strata tunnels under simulated dynamic water conditions according to claim 3 is characterized in that: The drainage system comprises a drainage electric pumping pipe and a drainage electric pumping pump, wherein the drainage electric pumping pump is arranged on the drainage electric pumping pipe; One end of the drainage electric water pumping pipe extends into the bottom of the water outlet partition groove, and the other end of the drainage electric water pumping pipe is connected to the water storage tank.

5. The test device for grouting composite strata tunnels simulating dynamic water conditions according to any one of claims 1 to 4, characterized in that: The single-ring segment is installed in the model box, and a plurality of grouting holes are symmetrically arranged in the single-ring segment; The number of the grouting systems is one or more, and each of the grouting systems is connected to one of the grouting holes.

6. The test device for grouting composite strata tunnels under simulated dynamic water conditions according to claim 5, characterized in that: The grouting system comprises a grouting air compressor, a grouting bucket and a grouting pipe. The grouting air compressor is used to increase the pressure of the grouting bucket, and the grouting pipe is provided with a flow rate regulating valve.

7. The test device for simulating dynamic water conditions in composite stratum tunnel grouting according to claim 1 is characterized by: The model box and the water storage tank are transparent structures; A marking grid, a main coordinate axis and a sub-coordinate axis are provided on one side of the model box, and the marking grid, the main coordinate axis and the sub-coordinate axis are all colored; The marking grid has a fixed width in both the horizontal and vertical directions, forming a plurality of square grids; The origin of the main coordinate axis is located at the position where the center of the ring of the single-ring segment is projected onto the model box, and the origin of each sub-coordinate axis is located at the position where the corresponding grouting hole is projected onto the model box.

8. The test device for simulating dynamic water conditions in composite stratum tunnel grouting according to claim 1 is characterized by: The data acquisition and analysis system comprises a matte black plastic plate, a high-speed camera, a data transfer line, an image acquisition card and a computer terminal, wherein the high-speed camera and the computer terminal are connected via the data transfer line, and the image acquisition card is connected to the data transfer line; The matte black plastic plate is provided with a plurality of barb components, and the matte black plastic plate is suspended on the model box through the barb components. The surface of the matte black plastic plate is rough, and diffuse reflection occurs when light is irradiated to the surface of the matte black plastic plate to reduce the intensity of reflection and refraction.

9. A test method for grouting a composite stratum tunnel under simulated dynamic water conditions, comprising using a test device for grouting a composite stratum tunnel under simulated dynamic water conditions as claimed in any one of claims 1 to 8, characterized in that: The following steps are also included: S1: Construct the system assembly structure; fill the model box with the permeable medium, and set the marking grid, main coordinate axis and sub-coordinate axis on the model box; S2: Start the dynamic water simulation system; control the water level of the water inlet and outlet troughs by controlling the water supply system and drainage system to form a stable seepage field; S3: Start the grouting system; inject grout into the model box according to the set grouting pressure and injection rate; in the grouting system, a plurality of grouting holes are arranged on the single ring segment and are symmetrically distributed to simulate grouting methods under different working conditions; The grouting methods include grouting method 1, grouting method 2 and grouting method 3; Among them, grouting method one is round glass particles, dynamic water grouting and single hole grouting; Grouting method two is round glass particles, dynamic water grouting and porous grouting; Grouting method three is round glass particles, dynamic water grouting and pressure relief drainage grouting; S4: Start the data acquisition and analysis system; record the diffusion process of the grouting slurry through a high-speed camera, and use a computer terminal to process the data to analyze the diffusion area, maximum diffusion radius and diffusion direction of the grouting slurry; S5: Clean the medium material; after completing the test, clean the permeable medium and replace the single-ring segments for recycling.

10. The test method for composite stratum tunnel grouting under simulated dynamic water conditions according to claim 9, characterized in that: In step S2, the following steps are included: S21: injecting water into the water storage tank, and pumping water from the water storage tank into the water supply container through the water supply electric pump; S22: Use a water supply air compressor to pressurize the water supply container, open the water supply valve, and fill water into the water inlet compartment through the water supply pipe to a predetermined height; S23: Control the dynamic water to enter the model box until the entire grouting area of ​​the model box is filled and finally flows into the water outlet partition groove; S24: water is poured into one side of the water inlet partition by a water supply electric pump, and water is pumped out from one side of the water outlet partition by a drainage electric pump, so as to realize the circulation of dynamic water between the water inlet partition and the water outlet partition, thereby forming a stable seepage field; S25: By controlling the water level height of the inlet and outlet baffles and utilizing the head difference to control the hydraulic gradient, different seepage field conditions can be simulated.

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