Porous medium grouting simulation test device and test method in flowing water environment

Abstract

The invention discloses a porous medium grouting simulation test device and method in a dynamic water environment, the porous medium grouting simulation test device in the dynamic water environment comprises an injected medium model system, a dynamic water supply system, a grouting system and a data acquisition system, and the injected medium model system comprises a tubular main body, the main body is made of a transparent material; the main body is provided with a first end and a second end which are opposite to each other, the first end is detachably connected with a first sealing piece through a connecting assembly, and the first sealing piece is provided with a water filling nozzle; the second end is detachably connected with a second sealing piece through a connecting assembly, and a water outlet is formed in the second sealing piece; a grouting opening is further formed in the side wall of the main body; the dynamic water supply system comprises a water storage tank, a water conveying pipe, a water conveying valve and a pressure adjusting mechanism. According to the invention, the grouting and water plugging reinforcement process of the water-rich unconsolidated formation can be really simulated indoors.

Description

Technical Field

[0001] The invention relates to the technical field of grouting simulation test, and in particular to a porous medium grouting simulation test device and a test method under a dynamic water environment. Background Art

[0002] Under the background of large-scale construction of major infrastructure, more and more railway tunnels, urban subways and other projects are gradually entering the construction and operation period. The hydrogeological conditions encountered during the construction of the project are also becoming increasingly complex, and various engineering hydrogeological disasters often occur. The management of adverse hydrogeological disasters in tunnels and underground space projects has become an important research direction. Among them, loose water-rich strata such as water-rich sand layers are difficult to manage and often encounter adverse geology. This type of stratum cannot prevent disasters in a timely and effective manner, and is very likely to induce serious engineering and environmental problems such as instability and damage of surrounding rocks, tunnel collapse, surface subsidence and groundwater loss, which will cause delays in the construction period, threaten personnel safety, cause property losses, and have adverse social impacts.

[0003] In the current construction of underground projects such as tunnels, the grouting method can improve the mechanical properties and overall stability of the stratum. The chemical slurry grouting method can achieve the purpose of water blocking, anti-seepage and reinforcement, and has become one of the important methods for water blocking and anti-seepage in water-rich loose strata.

[0004] At present, more and more research is being conducted on grouting materials and equipment. However, there are few experimental methods and devices that involve the main controlling factors and the influencing characteristics of each single factor that affect the penetration and diffusion laws of the injected slurry in the formation, water plugging, anti-seepage and reinforcement effects under different parameters such as head height, grouting pressure, formation particle size, and formation clay content in water-rich formations.

[0005] Most of the existing grouting test equipment and methods are used to study the reinforcement of strata with low water content. There are almost no grouting water blocking test equipment and methods for water-rich strata, and some existing equipment cannot truly simulate the grouting process in the strata.

[0006] Therefore, it is necessary to propose a porous medium grouting simulation test device and test method under a dynamic water environment to solve at least one of the above problems. Summary of the invention

[0007] In view of the defects existing in the prior art, an embodiment of the present invention provides a porous medium grouting simulation test device under a dynamic water environment, which can carry out a real simulation of the grouting and water plugging reinforcement process of water-rich loose formations indoors and can study the diffusion law, water plugging, anti-seepage and reinforcement effects of the slurry in the water-rich formations under the influence of different factors, so as to provide technical support for the formulation of actual grouting and water plugging reinforcement schemes for water-rich loose formations and the evaluation of grouting effects.

[0008] The specific technical solution of the implementation mode of the present invention is:

[0009] A porous medium grouting simulation test device under a dynamic water environment, the porous medium grouting simulation test device under a dynamic water environment comprising:

[0010] Injected medium model system, dynamic water supply system, grouting system and data acquisition system,

[0011] The injected medium model system comprises: a tubular main body with openings at both ends, the main body being made of a transparent material; the main body having a first end and a second end opposite to each other, the first end being provided with a first sealing member in a detachable connection through a connecting assembly, the first sealing member being provided with a water injection port; the second end being provided with a second sealing member in a detachable connection through a connecting assembly, the second sealing member being provided with a water outlet; and a grouting port being further provided on the side wall of the main body;

[0012] The dynamic water supply system comprises: a water storage tank, a water delivery pipe capable of connecting the water storage tank with the water injection port, a water delivery valve arranged on the water delivery pipe, and a pressure regulating mechanism for output pressure of the dynamic water supply system;

[0013] The grouting system comprises: a grouting bucket for holding slurry, a grouting pipe connecting the grouting bucket with the grouting port, a grouting machine and a grouting gun head arranged in the grouting pipe, wherein the grouting machine is used to adjust the grouting pressure output at the grouting gun head;

[0014] The data acquisition system comprises: a plurality of pore water pressure gauges arranged at intervals along the axial direction of the main body, a water flow meter arranged at the water outlet, and a data processing system electrically connected to the pore water pressure gauges and the water flow meter.

[0015] In a preferred embodiment, the main body is a plexiglass tube.

[0016] In a preferred embodiment, the connection assembly includes: bolts and a flange.

[0017] In a preferred embodiment, the first sealing member and the second sealing member are silicone pads.

[0018] In a preferred embodiment, the first sealing member has an outer side close to the connecting assembly and an inner side away from the connecting assembly, and a filter screen matching the inner diameter of the main body is also provided on the inner side of the first sealing member.

[0019] In a preferred embodiment, the second sealing member has an outer side close to the connecting assembly and an inner side away from the connecting assembly, and a permeable stone matching the inner diameter of the main body is further provided on the inner side of the second sealing member.

[0020] In a preferred embodiment, the pressure regulating mechanism includes a height adjusting component, which is used to adjust the height position of the water tank. The height adjusting component includes: a bracket, a pulley and a safety rope. The pulley is fixed in the middle position above the bracket, and the safety rope hoists the water tank at different heights through the pulley.

[0021] In a preferred embodiment, the grouting machine is a two-component hydraulic grouting machine, and the dynamic water supply system includes at least two slurry storage barrels.

[0022] In a preferred embodiment, the grouting system further comprises: a pressure gauge, the grouting pressure of the grouting machine is adjustable, and the pressure gauge is installed on the grouting gun head.

[0023] A porous medium grouting simulation test method under dynamic water environment based on the porous medium grouting simulation test device under dynamic water environment, the porous medium grouting simulation test method under dynamic water environment comprising:

[0024] Filling the screened injection medium into the injection medium model system;

[0025] Supplying dynamic water to the injected medium model system through the dynamic water supply system so that the dynamic water penetrates the injected medium model system;

[0026] After the dynamic water supply system is started, the data acquisition instrument is turned on; after the water flow in the injected medium model system is stabilized, the pore water pressure gauge pressure and the water flow data of the water outlet are recorded;

[0027] Start the grouting system and carry out grouting;

[0028] After grouting is stopped, the water flow change data of the water outlet of the injected medium model system within a predetermined time period is obtained, and the grouting consolidation body formed in the injected medium model system is cured; after curing for a predetermined time, demoulding is carried out, the grouting consolidation body is taken out, samples are made, and permeability performance tests and mechanical performance tests of the grouting consolidation body are carried out.

[0029] The technical solution of the present invention has the following significant beneficial effects:

[0030] The porous media grouting simulation test device and test method under a dynamic water environment provided in the implementation mode of the present application are specifically a kind of visualization test equipment and method that can carry out a real simulation of the grouting and water plugging reinforcement process of water-rich loose formations indoors and can study the diffusion law of the slurry in the water-rich formation under the influence of different factors, the water plugging, anti-seepage and reinforcement effects, which can monitor the data in real time, and is used to provide technical support for the formulation of actual grouting and water plugging reinforcement schemes for water-rich loose formations and the evaluation of grouting effects.

[0031] In the implementation manner of the present application, the main body of the injected medium formation simulation device is made of a portable, detachable and reusable transparent organic glass material, so that the grouting process is completely visualized, making it easy to observe the diffusion law of the slurry during the grouting process.

[0032] In the implementation manner of the present application, the dynamic water supply system simulation device can raise and lower the water supply bucket and provide different head pressures for the test, which is convenient for studying the influence of water-rich formations on the grouting effect under different head pressure conditions.

[0033] In the embodiment of the present application, the two ends of the plexiglass tube body of the injected medium simulation device are connected in a detachable manner. Media of different particle sizes can be filled in the injected medium simulation device, and the injected medium simulation device can be reused, which is convenient for studying the influence of particle size changes of the injected medium formation on the grouting effect.

[0034] In the embodiment of the present application, a water flow meter is installed outside the water outlet of the injected medium simulation device. According to the change of the water flow rate at the water outlet before and after grouting, the grouting and water blocking effect of the grouting test under different test conditions can be quantitatively evaluated.

[0035] In the implementation manner of the present application, the changes in water pressure in the injected medium before and after grouting monitored by a pore water pressure gauge installed in the injected medium can determine the diffusion state and reaction state of the slurry during the grouting process. The pore water pressure state at each monitoring point after the grouting is completed can also assist in determining the sealing effect after grouting.

[0036] In the implementation manner of the present application, the injected medium formation simulation device is detachable. After the grouting test is completed, the grouting consolidation body can be taken out to further study the changes in the permeability and mechanical properties of the grouting consolidation body under different test conditions, and make a quantitative evaluation of the anti-seepage reinforcement effect of the grouting.

[0037] With reference to the following description and drawings, specific embodiments of the present invention are disclosed in detail, indicating the manner in which the principles of the present invention can be adopted. It should be understood that the embodiments of the present invention are not limited in scope. Within the spirit and scope of the appended claims, the embodiments of the present invention include many changes, modifications and equivalents. Features described and / or shown for one embodiment can be used in one or more other embodiments in the same or similar manner, combined with features in other embodiments, or replace features in other embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings described herein are only for explanation purposes and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the various components in the figures are only schematic, used to help understand the present invention, and are not specifically limited to the shapes and proportional dimensions of the various components of the present invention. Those skilled in the art can select various possible shapes and proportional dimensions to implement the present invention according to the teachings of the present invention.

[0039] Figure 1 A schematic diagram of the structure of a porous medium grouting simulation test device in a dynamic water environment provided in an embodiment of the present application;

[0040] Figure 2 It is a schematic diagram of assembling an ultrafine filter screen and a silicone gasket at a water inlet of an injected medium simulation device provided in an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the installation of permeable stones at the water outlet of the injected medium simulation device provided in an embodiment of the present invention.

[0042] Figure 4 A schematic diagram of a plexiglass tube of a medium simulation device provided in an embodiment of the present invention.

[0043] Figure 5 It is a schematic diagram of the structure of a grouting consolidation body test block after cutting and grinding provided in an embodiment of the present invention;

[0044] Figure 6 A flowchart of the steps of a porous medium grouting simulation test method in a dynamic water environment provided in an embodiment of the present application.

[0045] Reference numerals of the present application:

[0046] 1. Water delivery valve;

[0047] 2. Water storage tank;

[0048] 3. Water pipe;

[0049] 4. Flange;

[0050] 5. Silicone gasket;

[0051] 6. Bolts;

[0052] 7. Filter;

[0053] 8. Organic glass tube;

[0054] 9. Injected medium;

[0055] 10. Pore water pressure gauge;

[0056] 11. Grouting pipe;

[0057] 12. Pressure gauge;

[0058] 13. Grouting machine;

[0059] 14. Slurry storage barrel;

[0060] 15. Permeable stone;

[0061] 16. Water flow meter;

[0062] 17. Water storage tank;

[0063] 18. Data acquisition system;

[0064] 19. Computer;

[0065] 20. Bracket;

[0066] 21. Pulley. DETAILED DESCRIPTION

[0067] The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0068] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0069] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0070] Based on the current status of grouting simulation: some existing test equipment and methods for grouting research are mostly used to study the reinforcement of strata with low water content, and the strata are simulated in iron sealed containers. The diffusion of slurry in the strata cannot be observed in real time, and there are almost no grouting water blocking test equipment and methods for water-rich strata.

[0071] It is necessary to develop a test equipment and method that can carry out a real simulation of the grouting and water plugging reinforcement process of water-rich loose strata indoors and can study the diffusion law of slurry in water-rich strata under the influence of different factors, water plugging, anti-seepage and reinforcement effects, so as to provide technical support for the formulation of actual grouting and water plugging reinforcement schemes for water-rich loose strata and the evaluation of grouting effects.

[0072] Please refer to Figures 1 to 5 In the embodiment of the specification of the present application, a porous medium grouting simulation test device under a dynamic water environment is provided, and the porous medium grouting simulation test device under a dynamic water environment may include: a model system of a medium to be injected, a dynamic water supply system, a grouting system and a data acquisition system 18, wherein the model system of the medium to be injected includes: a tubular main body with openings at both ends, and the main body is made of a transparent material; the main body has a first end and a second end opposite to each other, the first end is provided with a first sealing member in a detachable connection manner through a connecting component, and a water injection port is provided on the first sealing member; the second end is provided with a second sealing member in a detachable connection manner through a connecting component, and a water outlet is provided on the second sealing member; a grouting port is also provided on the side wall of the main body; the dynamic water supply system 18 comprises ... The water supply system includes: a water tank 17, a water pipe 3 that can connect the water tank 17 with the water injection port, a water valve 1 arranged on the water pipe 3, and a pressure regulating mechanism for the output pressure of the dynamic water supply system; the grouting system includes: a slurry storage barrel 14 for containing slurry, a grouting pipe 11 that connects the slurry storage barrel 14 with the grouting port, a grouting machine 13 and a grouting gun head arranged in the grouting pipe 11, and the grouting machine 13 is used to adjust the grouting pressure output at the grouting gun head; the data acquisition system 18 includes: a plurality of pore water pressure gauges 10 arranged at intervals along the axial direction of the main body, a water flow meter arranged at the water outlet, and a data processing system electrically connected to the pore water pressure gauge 10 and the water flow meter.

[0073] The present invention provides a porous medium grouting simulation test device under a dynamic water environment, which can carry out a real simulated grouting and water plugging reinforcement process of a water-rich loose stratum indoors and can study the diffusion law of the slurry in the water-rich stratum under the influence of different factors, the real-time monitoring data of the water plugging, anti-seepage and reinforcement effects, so as to provide technical support for the formulation of actual grouting and water plugging reinforcement scheme for water-rich loose strata and the evaluation of grouting effects.

[0074] The present application will be described in detail below with reference to specific drawings and implementation methods.

[0075] The porous medium grouting simulation test device provided in the dynamic water environment in the embodiment of the present application mainly includes: a model system of the injected medium, a dynamic water supply system, a grouting system and a data acquisition system 18, etc.

[0076] like Figure 4As shown, the injected medium model system may include a tubular body with two ends open. The body may be made of a high-pressure resistant transparent organic glass tube 8. Of course, the material of the body may also be made of other high-pressure resistant transparent materials. In the embodiment of the present application, the organic glass tube 8 is mainly used as an example for illustration, and the body of other materials may refer to the description of the present application.

[0077] In general, when the organic glass tube 8 is loaded with the injected medium 9, both ends of the organic glass tube 8 need to be sealed and ensure that a water injection port and a water outlet can be formed, so that the test fluid can enter the organic glass tube 8 through the water injection port, and the fluid in the organic glass tube 8 can flow out through the water outlet. Specifically, the organic glass tube 8 may include a first end and a second end opposite to each other, and the first end of the organic glass tube 8 may be provided with a first sealing member with a water injection port in a detachable manner through a connecting assembly, and the second end of the organic glass tube 8 may be provided with a second sealing member with a water outlet in a detachable manner through a connecting assembly.

[0078] The first seal and the second seal may be in the form of a silicone pad. The detachable connection may be in the form of a flange connection, and the connection assembly may include a bolt 6 and a flange 4. By using the bolt 6 and the flange 4 to tighten together, a pressing force can be applied to the first seal and the second seal, thereby ensuring the reliability of the seal at both ends.

[0079] In addition, in order to further ensure the sealing of both ends of the injected medium model system, the gaps where leakage may occur can be sealed with sealant.

[0080] like Figure 2 As shown, in one embodiment, the first sealing member has an outer side close to the connecting component and an inner side away from the connecting component, and the inner side of the first sealing member is also provided with a filter screen 7 matching the inner diameter size of the main body (plexiglass tube 8).

[0081] In this embodiment, a filter screen 7 having the same diameter as the organic glass tube 8 is pasted on the inner side of the silicone pad on the water inlet side of the grouting medium model system. The shape of the filter screen 7 can be circular, and its diameter can be the same as or close to the inner diameter of the organic glass tube 8. By setting the filter screen 7, the material filled in the grouting medium model can be stopped. For example, the filter screen 7 can be an ultra-fine filter screen 7, and the mesh of the filter screen 7 is smaller than the particle size of the material filled in the grouting medium model, so that it can be reliably stopped.

[0082] like Figure 3As shown, in one embodiment, the second sealing member has an outer side close to the connecting component and an inner side away from the connecting component, and the inner side of the second sealing member is also provided with a permeable stone 15 matching the inner diameter size of the main body (plexiglass tube 8).

[0083] In this embodiment, a permeable stone 15 (such as a permeable stone 15) having the same or similar inner diameter as the glass tube can be placed at the edge of the organic glass tube 8 on the inner side of the silicone pad on the outlet side of the grouting medium model system. Figure 5 For example, the permeable stone 15 can be a cylindrical section as a whole, and the length of the cylindrical section can be about 400 mm. The diameter of the permeable stone 15 can be the same as the inner diameter of the grouting medium model system, for example, about 600 mm.

[0084] The permeable stone 15 has good water permeability, and the water in the grouting medium model system is output to the outside through the water outlet by using the permeable stone 15.

[0085] In this embodiment, the dynamic water supply system can be connected to the water injection port to provide the dynamic water required for the test to the injected medium model system.

[0086] Specifically, the dynamic water supply system may include: a water storage tank 17, a water pipe 3 and a water valve 1, etc.

[0087] During the test, water is supplied to the water tank 17 through an external faucet to keep the water level in the water tank 17 at a fixed level. One end of the water pipe 3 is connected to the water tank 17, for example, it can be connected to the bottom of the water tank 17, and the other end is connected to the water inlet of the injected medium model system. The water valve 1 is arranged on the water pipe 3 to control the on and off of the water pipe 3.

[0088] Among them, a scale can be set on the side wall of the water storage tank 17 to intuitively display the liquid level in the water storage tank 17, which is conducive to monitoring the liquid level in the water storage tank 17. When the liquid level in the water storage tank 17 fluctuates, it can be adjusted in time. Of course, in addition, the liquid level in the water storage tank 17 can also be monitored by setting a liquid level meter in the water storage tank 17.

[0089] In one embodiment, the dynamic water supply system may further include a pressure regulating mechanism for the output pressure of the dynamic water supply system. The pressure regulating mechanism is used to adjust the pressure output from the dynamic water supply system to the water injection port. Specifically, the pressure regulating mechanism can be implemented by changing the height of the water storage tank 17.

[0090] The pressure regulating mechanism may include a height regulating component, and the height regulating component is used to adjust the height position of the water storage tank 17. Specifically, the height regulating component may include: a bracket 20, a pulley 21, a safety rope, and the like.

[0091] The pulley 21 is fixed at the middle position above the bracket 20, and the safety rope can be used to hoist the water tank 17 at different heights through the pulley 21 to adjust the dynamic water pressure required for the simulation test.

[0092] In this embodiment, the grouting system is used to grout the injected medium model system.

[0093] Specifically, the grouting system may include: a grouting machine 13, a grout storage barrel 14, slurry, a grouting pipe 11, a grouting gun head, etc. A grouting hole for communicating with the grouting system is provided on the side wall of the main body of the injected medium model system.

[0094] The slurry is placed in a slurry storage barrel 14, which is connected to a grouting machine 13 via a grouting pipe 11. The tail end of a grouting gun head is connected to the grouting machine 13 via a grouting pipe 11, and the gun head injects grout into the injected medium model system through a grouting hole opened on the pipe body of the injected medium model system.

[0095] Preferably, the grouting machine 13 is a two-component hydraulic grouting machine 13, and the grouting slurry can be a single liquid or a two-component slurry, which can be flexibly adjusted according to the test requirements to simulate slurries of different components. When the grouting slurry is also a two-component slurry, the slurry storage barrel 14 can be two, and the two slurry storage barrels 14 can be connected to the grouting machine 13 respectively.

[0096] The grouting system may further include: a pressure gauge. The grouting pressure of the grouting machine 13 is adjustable, the grouting pipe 11 is a high-pressure resistant grouting pipe 11, and the pressure gauge is installed on the grouting gun head to observe the injection pressure of the slurry.

[0097] In one embodiment, the data acquisition system 18 may include: a pore water pressure meter 10, a water flow meter, a data conductor, a data acquisition instrument, and a data processing system (such as a computer 19).

[0098] In this embodiment, a plurality of openings are provided on the main body of the grouting medium model system at intervals along the axial direction. Specifically, the positions of the openings can be preset according to the test requirements, and this application does not make any specific limitation here.

[0099] By opening holes at different predetermined positions on the pipe body of the grouting medium model system, the pore water pressure gauge 10 is buried in the injected medium 9 in the pipe of the grouting medium model system, connected to the data acquisition instrument through a data wire, and the opening position is sealed with a sealant; the water flow meter is installed on the water outlet of the injected medium model system, and connected to the data acquisition instrument through the connecting wire; the data acquisition instrument is connected to the computer 19 through the data wire, and the computer 19 analyzes the data collected by the data acquisition instrument.

[0100] Furthermore, the above-mentioned test device also includes a grouting consolidation body standard specimen production system, and the standard specimen production system includes a coring machine, a cutting machine and a grinder.

[0101] In the implementation manner of the present application, the main body of the stratum simulation device for the injected medium 9 is made of a portable, detachable and reusable transparent organic glass material, so that the grouting process is completely visualized, which facilitates the observation of the diffusion law of the slurry during the grouting process.

[0102] In the implementation manner of the present application, the dynamic water supply system simulation device can raise and lower the water supply bucket and provide different head pressures for the test, which is convenient for studying the influence of water-rich formations on the grouting effect under different head pressure conditions.

[0103] In the embodiment of the present application, the two ends of the organic glass tube 8 of the injected medium simulation device are connected in a detachable manner. The injected medium simulation device can be filled with media of different particle sizes. The injected medium simulation device can be reused, which is convenient for studying the influence of the particle size change of the injected medium 9 formation on the grouting effect.

[0104] In the embodiment of the present application, a water flow meter 16 is installed outside the water outlet of the injected medium simulation device. According to the change of the water flow at the water outlet before and after grouting, the grouting and water blocking effect of the grouting test under different test conditions can be quantitatively evaluated.

[0105] Example: In the model test using the above device, the water blocking effect after grouting can be expressed by the water blocking rate:

[0106]

[0107] Where: SE represents water blocking rate (%);

[0108] Q 0 Indicates the seepage rate before grouting (ml / min);

[0109] Q g Indicates the seepage rate after grouting (ml / min).

[0110] In multiple groups of tests under different conditions, the water blocking rate after each grouting test can be measured according to the above formula, and the water blocking effect can be determined according to the size of the water blocking rate.

[0111] In the embodiment of the present application, the pore water pressure gauge 10 installed in the injected medium 9 monitors the changes in water pressure in the injected medium 9 before and after grouting, which can determine the diffusion state and reaction state of the slurry during the grouting process. The pore water pressure state at each monitoring point after the grouting is completed can also assist in determining the sealing effect after grouting.

[0112] For example, in the model test using the above device, each group of tests starts collecting pore water pressure at each point of the model device 30 seconds before grouting, and stops collecting after the grouting is completed and the pore water pressure changes in the device are stable. Taking a group of tests as an example, the monitoring data of pore water pressure before and after grouting are analyzed in detail.

[0113] Take the pressure gauges distributed from left to right as an example: the first pressure gauge, the second pressure gauge, the third pressure gauge and the fourth pressure gauge. It can be seen from the data of pore water pressure change over time that grouting starts from 30s of data collection. Before grouting, the pore water pressure at each point of the sand layer has a certain dissipation due to different positions, and the water pressure transmission has a certain dissipation, and the water pressure at each point fluctuates around 5KPa. After the grouting starts, the slurry is instantly injected into the sand layer, which has an expulsion effect on the water in the sand layer, causing the pore water pressure at the second and third pressure gauges to increase rapidly; since the fourth pressure gauge is far away from the grouting pipe 11 and close to the water outlet, the pressure dissipates faster, so the pressure value is not as large as that at the second and third pressure gauges, and the pressure change is delayed: the first pressure gauge is located in the upstream countercurrent section and is far away from the grouting pipe 11, and is limited by the influence of slurry expulsion, so the pressure value is not as large as that at the other pressure gauges.

[0114] As the grouting progressed, the two-component slurry began to react, and the pore water pressure at each pressure gauge continued to increase but at a slower rate. At about 200 seconds into the grouting, the pressure values ​​at the second and third pressure gauges reached their maximum values. As the grouting progressed, the values ​​at each pressure gauge maintained a balance for a period of time, with little change. At about 400 seconds, the pressure at each location began to drop sharply, the slurry gradually solidified, and the pore water pressure decreased accordingly. At about 600 seconds, the pore water pressure at the second, third, and fourth pressure gauges was close to 0, indicating that the reaction was basically completed at this time. After the slurry reacted and consolidated with the sand layer, the water flow could not flow in the pores of the sand particles, achieving a good plugging effect. Since the diffusion distance of the slurry in the reverse water section was only 17c, it failed to diffuse to the position of the first pressure gauge. After the reaction, the pore water pressure at this location was similar to the pressure value before grouting.

[0115] In the embodiment of the present application, the stratum simulation device of the injected medium 9 is detachable. After the grouting test is completed, the grouting consolidation body can be taken out to further study the changes in the permeability and mechanical properties of the grouting consolidation body under different test conditions, and make a quantitative evaluation of the anti-seepage reinforcement effect of the grouting.

[0116] Example: (1) Anti-seepage effect

[0117] In engineering, the permeability coefficient is generally used to characterize the anti-seepage performance of the grouting consolidation body. The smaller the permeability coefficient of the grouting consolidation body, the stronger the anti-seepage ability of the grouting consolidation body. In the model test using the above device, the consolidation body after being taken out can be processed into a certain size, and the permeability coefficient can be measured using a permeameter.

[0118] (2) Reinforcement effect

[0119] In the model test using the above device, the taken-out consolidated body can be processed into a certain size, and a uniaxial compression test is carried out on the consolidated body to compare the strength of the consolidated body after grouting under different test conditions.

[0120] See also Figure 6 Based on the porous medium grouting simulation test device under a dynamic water environment provided in the above embodiment, the present invention provides a porous medium grouting simulation test method under a dynamic water environment. When the method is executed, the porous medium grouting simulation test device under a dynamic water environment is used. The porous medium grouting simulation test method under a dynamic water environment may include the following steps:

[0121] Step S1: Filling the screened injection medium 9 into the injection medium model system;

[0122] Step S2: supplying dynamic water to the injected medium model system through the dynamic water supply system, so that the dynamic water penetrates the injected medium model system;

[0123] Step S3: After the dynamic water supply system is started, the data acquisition instrument is turned on; after the water flow in the injected medium model system is stabilized, the pressure of the pore water pressure gauge 10 and the water flow data of the water outlet are recorded;

[0124] Step S4: starting the grouting system to perform grouting;

[0125] Step S5: After stopping grouting, obtaining the water flow change data of the water outlet of the injected medium model system within a predetermined time period, and curing the grouting consolidation body formed in the injected medium model system; after curing for a predetermined time, demolding is performed, the grouting consolidation body is taken out, a sample is made, and a permeability performance test and a mechanical property test of the grouting consolidation body are carried out.

[0126] In this embodiment, regarding step S1:

[0127] Assemble the injected medium model system, place a permeable stone 15 with the same diameter as the glass tube on the inner side of the water outlet of the glass tube of the model system, fasten the organic glass tube 8 with the silicone pad and the flange 4 with bolts 6, and seal the edge gap with sealant; install the water flow meter 16 on the water outlet, and insert the pore water pressure gauge 10 into the glass tube body of the model system at a predetermined position, and seal the tube body opening gap with hot melt adhesive and sealant; spray a layer of release agent on the tube body of the model system, fill the screened injected medium 9 into the glass tube of the model system, and compact it in layers according to the predetermined density when filling; after the injected medium 9 is filled, fasten the water inlet side of the model system with the silicone pad and the flange 4 with bolts 6, stick an ultrafine filter 7 with the same diameter as the tube on the inner side of the silicone pad, and seal the edge gap with sealant.

[0128] In this embodiment, regarding step S2:

[0129] Prepare the dynamic water supply system, hang the water tank 2 at the predetermined test position, open the external water supply valve to make the water level in the water tank 2 at a predetermined constant water level, connect the bottom of the water tank 2 and the water inlet of the grouting model system with a water pipe 3, open the water inlet valve, and allow the dynamic water to penetrate the injected medium model system and flow out from the water outlet.

[0130] In this embodiment, regarding step S3:

[0131] Start the data acquisition system 18, after the dynamic water supply system is started, turn on the data acquisition instrument, and after the water flow in the injected medium model system is stable, record the pore water pressure gauge 10 pressure and the water flow data of the water outlet;

[0132] In this embodiment, regarding step S4:

[0133] Start the grouting system, make a hole in the middle of the pipe body of the medium model system to be injected, insert the grouting pipe 11 to the center of the medium 9 to be injected, and seal the hole with a sealant; connect the grouting gun head to the grouting pipe 11, start the grouting machine 13, adjust the grouting pressure, and when the value of the grouting pressure gauge 12 reaches the predetermined grouting pressure, open the grouting gun head valve and start grouting; according to the type of grouting slurry used in the test, stop grouting when the predetermined grouting volume is reached or the slurry injection is difficult.

[0134] In this embodiment, regarding step S5:

[0135] After stopping the grouting, record the water flow change data of the outlet of the injected medium model system for 10 minutes, and maintain the grouting consolidation body according to the test requirements; after maintaining for a predetermined time, demould, take out the grouting consolidation body, make samples, and carry out permeability performance test and mechanical property test of the grouting consolidation body.

[0136] Furthermore, the porous media grouting simulation test method under a dynamic water environment can study the diffusion law of grouting materials under different dynamic water pressures, grouting pressures, and injected media 9 conditions, monitor and record the pore water pressure data and outlet water flow change data at specific locations in real time, analyze the permeability and mechanical property change laws of the consolidated body after grouting, and evaluate the grouting repair and reinforcement effect.

[0137] The test device in this application is easy to operate, the test results are reliable and reusable, and it is particularly suitable for orthogonal test methods that require multiple groups of tests. The specific steps of each group of tests are as follows:

[0138] 1) First, according to the volume of the formation simulation device of the injected medium 9, weigh the injected medium 9 and clay soil of the required weight for each group of tests, and use a stirring rod to fully mix the injected medium 9 and clay soil; apply a layer of vaseline lubricating paste inside the simulation device to prevent the solidified body after grouting from sticking to the inside of the simulation device and being unable to be removed; place a round permeable stone 15 with a diameter of 10 cm and a thickness of 1 cm on one side of the water outlet of the simulation device, install the water outlet flange 4, and place a layer of silicone gasket 5 between the flange 4 and the simulation device, and fasten with bolts 6.

[0139] 2) Load the injected medium 9 prepared for the test into one side of the water inlet. Control the tamping height according to the weight of the injected medium 9 loaded each time to ensure that the sand layer reaches the density required by the test. After filling, install the water inlet flange 4. Place an ultra-fine filter screen 7 with a diameter of 10 cm on the inside of the flange 4. Place a layer of silicone gasket 5 between the flange 4 and the simulation device, and also fasten them with bolts 6.

[0140] 3) According to the test requirements, pore water pressure gauges 10 are arranged at different positions of the horizontally placed injected medium 9 formation simulation device, and the data acquisition instrument is connected. After the pore water pressure collection and debugging are normal, the openings on the simulation device are sealed with hot melt adhesive; a hole is opened in the middle of the simulation device, and a grouting pipe 11 with a diameter of 1 cm is installed, and the pores are sealed with hot melt adhesive.

[0141] 4) According to the design of each group of experiments, the water storage barrel 2 is hung at different heights, and the bottom of the barrel is connected to the pipeline of the injected medium 9 formation simulation device; the water level of the water storage barrel 2 of the water head simulation device is kept at a constant level of 5L, and the water supply valve is opened to allow the dynamic water to flow through the formation simulation device, and observe whether the water inlet and outlet of the simulation device and the pipe body are leaking. If there is leakage, it is sealed again with hot melt adhesive; after the water flow rate at the water outlet is stable, start to read and record the data of the pore water pressure gauge 10, and record the water flow rate Q0 per minute displayed by the water flow meter 16 at the water outlet;

[0142] 5) Connect the grouting machine 13 suction pipe to the two-component slurry storage barrel 14, start the grouting machine 13, and debug the grouting machine 13 to a normal working state. When the pressure gauge 12 reaches the grouting pressure required by the test, open the grouting valve to start grouting, and keep the grouting pressure unchanged. When it becomes difficult to inject the slurry, stop grouting.

[0143] 6) After the grouting is completed, the water head pressure is kept unchanged, and the water flow changes at the outlet are observed. 10 minutes after the grouting is completed, the data collection of the pore water pressure meter 10 is stopped, and the water flow rate Qg per minute at the outlet is recorded; the grouting medium 9 formation simulation device is placed in a constant temperature curing room at a room temperature of 26°C for 1 day.

[0144] 7) After one day of curing, the formation simulation device was demoulded, the grouting consolidation body was taken out, the length of the downstream and upstream sections of the consolidation body was measured with a tape measure, and the customized drill tube was used to take samples ( Figure 5 As shown), variable head permeability test of the consolidated body is carried out.

[0145] 8) Use a cutting machine to cut 3 test blocks of size 5cm×5cm×5cm from the consolidated body, record the numbers, put them in a water tank, and place them in a constant temperature curing room for 7 days to conduct an unconfined compressive strength test on the consolidated body test blocks.

[0146] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, and they cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0147] The above-mentioned various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0148] The above are only a few embodiments of the present invention. Although the embodiments disclosed by the present invention are as above, the contents are only embodiments adopted for facilitating the understanding of the present invention and are not used to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modification and change in the form and details of the embodiments without departing from the spirit and scope disclosed by the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined by the attached claims.

Claims

1. A porous medium grouting simulation test device under a dynamic water environment, characterized in that: The porous medium grouting simulation test device under dynamic water environment comprises: a model system of the injected medium, a dynamic water supply system, a grouting system and a data acquisition system. The injected medium model system comprises: a tubular main body with openings at both ends, the main body being made of a transparent material; the main body having a first end and a second end opposite to each other, the first end being provided with a first sealing member in a detachable connection through a connecting assembly, the first sealing member being provided with a water injection port; the second end being provided with a second sealing member in a detachable connection through a connecting assembly, the second sealing member being provided with a water outlet; and a grouting port being further provided on the side wall of the main body; The dynamic water supply system comprises: a water storage tank, a water delivery pipe capable of connecting the water storage tank with the water injection port, a water delivery valve arranged on the water delivery pipe, and a pressure regulating mechanism for output pressure of the dynamic water supply system; The grouting system comprises: a grouting bucket for holding slurry, a grouting pipe connecting the grouting bucket with the grouting port, a grouting machine and a grouting gun head arranged in the grouting pipe, wherein the grouting machine is used to adjust the grouting pressure output at the grouting gun head; The data acquisition system comprises: a plurality of pore water pressure gauges arranged at intervals along the axial direction of the main body, a water flow meter arranged at the water outlet, and a data processing system electrically connected to the pore water pressure gauges and the water flow meter.

2. The porous medium grouting simulation test device under dynamic water environment according to claim 1, characterized in that: The main body is an organic glass tube.

3. The porous medium grouting simulation test device under dynamic water environment according to claim 1, characterized in that: The connecting assembly comprises bolts and a flange.

4. The porous medium grouting simulation test device under dynamic water environment according to claim 3, characterized in that: The first sealing member and the second sealing member are silicone pads.

5. The porous medium grouting simulation test device under dynamic water environment according to claim 1, characterized in that: The first sealing member has an outer side close to the connecting assembly and an inner side away from the connecting assembly. The inner side of the first sealing member is also provided with a filter screen matching the inner diameter size of the main body.

6. The porous medium grouting simulation test device under dynamic water environment according to claim 1, characterized in that: The second sealing member has an outer side close to the connecting assembly and an inner side away from the connecting assembly. The inner side of the second sealing member is also provided with a permeable stone matching the inner diameter size of the main body.

7. The porous medium grouting simulation test device under dynamic water environment according to claim 1, characterized in that: The pressure regulating mechanism includes a height adjusting component, which is used to adjust the height position of the water tank. The height adjusting component includes: a bracket, a pulley and a safety rope. The pulley is fixed in the middle position above the bracket, and the safety rope hoists the water tank at different heights through the pulley.

8. The porous medium grouting simulation test device under dynamic water environment according to claim 1, characterized in that: The grouting machine is a two-component hydraulic grouting machine, and the dynamic water supply system includes at least two slurry storage barrels.

9. The porous medium grouting simulation test device under dynamic water environment according to claim 1, characterized in that: The grouting system further comprises: a pressure gauge, the grouting pressure of the grouting machine is adjustable, and the pressure gauge is installed on the grouting gun head.

10. A porous medium grouting simulation test method under dynamic water environment based on the porous medium grouting simulation test device under dynamic water environment according to any one of claims 1 to 9, characterized in that: The porous medium grouting simulation test method under dynamic water environment comprises: Filling the screened injection medium into the injection medium model system; Providing dynamic water to the injected medium model system through a dynamic water supply system so that the dynamic water penetrates the injected medium model system; After the dynamic water supply system is started, the data acquisition instrument is turned on; after the water flow in the injected medium model system is stabilized, the pore water pressure gauge pressure and the water flow data of the water outlet are recorded; Start the grouting system and carry out grouting; After grouting is stopped, the water flow change data of the water outlet of the injected medium model system within a predetermined time period is obtained, and the grouting consolidation body formed in the injected medium model system is cured; after curing for a predetermined time, demoulding is carried out, the grouting consolidation body is taken out, samples are made, and permeability performance tests and mechanical performance tests of the grouting consolidation body are carried out.

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