A device and method for testing the blocking performance of grouting joints throughout their life cycle

Abstract

This application belongs to the field of environmental geotechnical engineering technology or prevention and control of groundwater pollution in mining areas, and in particular relates to a device and method for testing the blocking performance of a grouting junction entity throughout its life cycle. The device is simple and easy to use overall, and can simultaneously control temperature, suction, groundwater flow rate, and water chemical environment, thereby realizing the maintenance of the grouting junction entity and the blocking performance test throughout its life cycle under simulated actual working conditions. At the same time, the device has low maintenance costs and is applicable in actual projects, and has important engineering significance and theoretical research value.

Description

Technical Field

[0001] The present application relates to the field of environmental geotechnical engineering technology or the field of groundwater pollution prevention and control technology in mining areas, and in particular to a device and method for testing the blocking performance of a grouting joint throughout its entire life cycle. Background Art

[0002] Manganese ore resources are an important strategic mineral in my country, widely used in fields such as steelmaking, chemical manufacturing, and electronics. However, long-term, large-scale manganese mining activities have significantly altered the hydrogeological conditions in mining areas, leading to highly developed rock joint and fissure systems and a more complex hydrodynamic system. When rainfall infiltrates the mining area, it interacts with manganese-bearing rock and soil, undergoing chemical leaching and producing highly concentrated manganese-contaminated water. This manganese-contaminated water migrates along joints and fissures and diffuses into surrounding aquifers through groundwater runoff, significantly increasing the concentration of manganese ions in the groundwater. The large volume of water gushing out and the complex runoff pathways further exacerbate the scope and intensity of the pollution, posing a serious threat to the safety of regional groundwater resources and the sustainability of the ecological environment. This environmental risk is particularly prominent in areas with concentrated manganese ore resources, necessitating the development of effective and scientific pollution prevention and control strategies to mitigate its adverse effects.

[0003] Among various pollution prevention and control technologies, cement-based composite grouting and plugging technology is widely considered a cost-effective method for managing joint and fissure contamination in manganese mining areas due to its excellent low permeability and high adsorption capacity for heavy metal ions. By plugging fissures through grouting, this technology can effectively prevent the migration and diffusion of manganese ions while reducing the permeability of mine water, thereby protecting groundwater resources. However, over the long term, the grouting material's barrier properties against heavy metal pollutants and its ability to block water can gradually weaken due to multiple factors such as material degradation, changes in the chemical environment, groundwater level fluctuations, and dry-wet cycles. This performance degradation not only increases the risk of groundwater contamination but also limits the optimization and large-scale application of this technology. Currently, research on the mechanisms of grouting performance changes throughout its life cycle and systematic evaluation methods is still in its early stages, and in-depth exploration at both the theoretical and practical levels is urgently needed to promote the improvement and promotion of this technology.

[0004] Permeability and membrane effect are key indicators for measuring a material's ability to block ion migration. They can intuitively reflect the blocking performance of grouting junctions and predict their service life. However, due to the special curing environment and conditions required during the formation of grouting junctions, traditional sample preparation methods are difficult to meet the relevant testing requirements. In addition, although the commonly used clay plate method can be used for unsaturated suction control research, it has problems such as complex operation, limited suction control range, and high cost, which further restrict the systematic research on the blocking performance of unsaturated grouting junctions. Overall, the following problems still exist:

[0005] (1) Currently, there are few studies on the evaluation of the solid blocking performance of grouting junctions, and few reports on the research on the solid membrane effect of grouting junctions. There is no device for testing the solid membrane effect of grouting junctions.

[0006] (2) There is no instrument that integrates both permeability and membrane effect testing functions;

[0007] (3) Some researchers have developed a saturated clay film effect test device, but there is no mature unsaturated film effect test device;

[0008] (4) Research in related fields uses clay plates to control suction to achieve an unsaturated state, which has the disadvantages of complicated experimental operations, long time consumption, limited suction control range, and high equipment costs;

[0009] (5) The curing of the structure needs to be carried out in a specific environment. The existing membrane effect test equipment is generally large in size and is not convenient for curing in a curing box.

[0010] (6) The state (strength, volume, blocking performance, etc.) of the structure will change during the maintenance process and service process, and there is a lack of equipment that can test the membrane effect of the structure throughout its life cycle.

[0011] In summary, the development of a simple, efficient, and economical device and method for testing the blocking performance of grouting joints has significant scientific and engineering significance. This research not only provides a scientific basis for evaluating the blocking performance and water shutoff capacity of grouting joints throughout their life cycle, but also offers theoretical support and practical guidance for environmental pollution prevention and control and resource conservation in manganese mining areas and beyond, thereby promoting innovation and sustainable development in mining ecological and environmental governance technologies. Summary of the Invention

[0012] The embodiment of the present application provides a device and method for testing the blocking performance of a grouting junction entity throughout its life cycle. The device and method are generally simple and easy to use, can economically and efficiently test the membrane effect of a grouting junction entity, and can evaluate its blocking performance and water blocking performance throughout its life cycle. At the same time, the device has low maintenance costs, is applicable in actual projects, and has important engineering significance and theoretical research value.

[0013] To this end, according to one aspect of the present application, a device for testing the blocking performance of a grouting joint throughout its life cycle is provided, comprising:

[0014] An integrated test chamber for curing and testing includes a rigid cylinder, a base, a connecting assembly, and an upper sealing body. The base is detachably mounted on the bottom of the rigid cylinder via the connecting assembly. The upper sealing body is slidingly and sealingly mounted within the rigid cylinder. The base, the interior of the rigid cylinder, and the upper sealing body enclose a chamber for accommodating paste grouting material. An annular permeable stone is embedded in the inner wall of the rigid cylinder, and permeable stones are embedded in the top of the base and the bottom of the upper sealing body.

[0015] A gas phase suction control component is connected to two opposite sides of the annular permeable stone and controls the suction of the sample in the accommodating cavity by a gas phase method;

[0016] a temperature control component, for controlling the internal temperature of the accommodating cavity;

[0017] The infiltration assembly includes a liquid storage container and a liquid collection container. The bottom of the base is provided with a water inlet connected to the permeable stone thereon, and the top of the upper sealing body is provided with a water outlet connected to the permeable stone thereon. The bottom of the liquid storage container is connected to the water inlet via a water inlet pipe, and the water inlet pipe is provided with a valve. The water outlet is connected to the liquid collection container via an outlet pipe. The position of the liquid storage container is higher than that of the liquid collection container.

[0018] A solution circulation device, comprising two sets of solution circulation components, each of which comprises a supply bottle for providing injection liquid, an inlet peristaltic pump connected to the supply bottle via an inlet pipe, a collection bottle for collecting liquid, and a discharge peristaltic pump connected to the collection bottle via an outlet pipe, wherein the inlet pipe and the outlet pipe of one set of the solution circulation components are connected to the permeable stone on the base; and the inlet pipe and the outlet pipe of the other set of the solution circulation components are connected to the permeable stone on the upper sealing body; and

[0019] The differential pressure monitoring component is used to monitor the chemical osmotic pressure difference between the top and bottom ends of the sample.

[0020] According to another aspect of the present application, a method for testing the blocking performance of a grouting junction entity throughout its life cycle is provided. Based on the above-mentioned device for testing the blocking performance of a grouting junction entity throughout its life cycle, the method for testing the blocking performance of a grouting junction entity throughout its life cycle comprises the following steps:

[0021] S1. Sample preparation: Prepare paste grouting material according to design requirements;

[0022] S2. Loading: Loading the sample in the integrated test chamber for curing and testing;

[0023] S3. Simulating actual curing conditions: Adjusting the temperature control assembly according to the actual site temperature environment to simulate the site temperature conditions; injecting a certain concentration of salt solution into the supply bottles of the two sets of the solution circulation assembly according to the actual site water chemistry to simulate the site groundwater conditions; setting the flow rates of the inlet and outlet peristaltic pumps of the two sets of the solution circulation assembly according to the actual site groundwater flow rate to simulate the site groundwater flow rate; finally, preparing a saturated solution in the gas phase suction control assembly according to the actual site unsaturated state to simulate unsaturated curing conditions;

[0024] S4. Sample curing: Under the curing conditions set in step S3, curing for a certain number of days to complete the sample curing;

[0025] S5. Cleaning the solid: After the curing is completed, close the two sets of the solution circulation components and the gas phase suction control component, replace the solution in the supply bottle of the two sets of the solution circulation components with distilled water, adjust the flow rate of the peristaltic pump for liquid inlet and outlet, and continuously measure the conductivity of the liquid in the collection bottle. When the conductivity is less than half the conductivity of the salt solution used in the supply bottle of the solution circulation component in step S3, the solid is considered to be cleaned;

[0026] S6. Conduct a penetration test using the penetration component;

[0027] S7. Conduct membrane effect tests under saturated / unsaturated conditions;

[0028] S8. Take out the knot and divide it into three parts. Use the filter paper method to test the suction of each part of the knot. Take the average value and record it as the actual suction s. s ;

[0029] S9. Change the test conditions and repeat the above test steps to carry out the grouting joint solid blocking performance test under different working conditions;

[0030] S10. Draw the relationship curve between curing time, actual suction, permeability coefficient and membrane efficiency coefficient to comprehensively evaluate and predict the blocking performance of the grouting entity.

[0031] The device and method for testing the blocking performance of grouting joints throughout their life cycle provided by this application have at least the following beneficial effects:

[0032] (1) The test device uses a gas phase method to control suction. Compared with the existing device that uses clay plates to control suction, the suction loading speed is fast and the suction control range is wide, which realizes the test of the unsaturated membrane effect of grouting entities within a wide suction range. In addition, the instrument and equipment are simple in composition, easy to operate, low in cost, small in space occupation, and have great value for wide promotion and application.

[0033] (2) The test device includes a gas phase suction control component, an integrated curing and testing test chamber, and two sets of solution circulation components. It can control different curing conditions according to the actual conditions on site, and realize the control of unsaturated conditions, flow rate control, temperature control, and chemical environment control, which greatly restores the actual curing conditions and ensures the practicality of the test results.

[0034] (3) In view of the phase change characteristics (from paste to solid phase) during the curing process of grouting materials, a special sample filling method was proposed, which enabled the test curing, saturated / unsaturated permeability test and membrane effect test to be completed in the same test chamber, which is simple to operate, improves the test efficiency and saves costs;

[0035] (4) A method for evaluating the blocking performance of grouting junctions throughout their entire life cycle was proposed. Compared with traditional evaluation methods, this method comprehensively considers the permeability, suction, and membrane effect of the grouting junctions, and also introduces a time variable. By setting different curing times and controlling different curing environments, the evaluation of the blocking performance (suction, membrane effect, and permeability) of grouting junctions throughout their entire life cycle under various working conditions is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0037] in:

[0038] Figure 1 1 is a schematic diagram of the overall structure of a device for testing the blocking performance of a grouting joint throughout its life cycle, according to an embodiment of the present application;

[0039] Figure 2 Schematic diagram of the sample loading process of the integrated test chamber for curing and testing in a device for testing the blocking performance of a grouting joint throughout its life cycle, shown in one embodiment of the present application;

[0040] Figure 3 This is a test result diagram of the full life cycle retardation performance test method using a grouting junction entity according to an embodiment of the present application, wherein ω is the membrane efficiency coefficient, t is the curing time, k is the permeability coefficient, s is the loading suction, s s is the actual suction force;

[0041] Figure 4 This is a flowchart of the steps of using a grouting joint entity full life cycle blocking performance test method to simulate blocking performance testing under extreme working conditions, as shown in one embodiment of the present application.

[0042] Description of main component symbols:

[0043] 10. Rigid cylinder; 11. Base; 12. Connecting assembly; 13. Upper sealing body; 14. Annular permeable stone; 15. Permeable stone; 1. Gas circulation pump; 2. First liquid storage tank; 3. Second liquid storage tank; 4. Pipeline; 5. CNC display screen; 6. Temperature sensor; 7. Heating belt; 8. Liquid storage container; 9. Liquid collecting container; 20. Pressure difference sensor; 21. Data acquisition instrument; 22. Supply bottle; 23. Liquid inlet peristaltic pump; 24. Collecting bottle; 25. Liquid outlet peristaltic pump; 30. Filter paper; 31. Inverted "T"-shaped top cover; 32. Sample. DETAILED DESCRIPTION

[0044] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many other forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0045] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0046] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0048] According to one aspect of the present application, an embodiment of the present application provides a device for testing the blocking performance of a grouting joint throughout its life cycle, such as Figure 1 As shown, it includes an integrated test chamber for curing and testing, a gas phase suction control component, a temperature control component, a permeation component, a solution circulation device, and a pressure difference monitoring component.

[0049] The integrated test chamber for curing and testing includes a rigid cylinder 10, a base 11, a connecting assembly 12, and an upper sealing body 13. The base 11 is detachably mounted on the bottom of the rigid cylinder 10 via the connecting assembly 12. The upper sealing body 13 is slidingly and sealingly mounted within the rigid cylinder 10. The base 11, the interior of the rigid cylinder 10, and the upper sealing body 13 enclose a chamber for accommodating paste grouting material. An annular permeable stone 14 is embedded in the inner wall of the rigid cylinder 10, and permeable stones 15 are embedded in the top of the base 11 and the bottom of the upper sealing body 13. A gas phase suction control assembly is connected to opposite sides of the annular permeable stone 14 to control the suction of the sample 32 within the chamber using a gas phase method. A temperature control assembly is used to control the internal temperature of the chamber. The infiltration assembly includes a liquid storage container 8 (such as a faucet bottle) and a liquid collecting container 9 (such as a measuring cylinder). The bottom of the base 11 is provided with a water inlet connected to the permeable stone 15 thereon, and the top of the upper sealing body 13 is provided with a water outlet connected to the permeable stone 15 thereon. The bottom of the liquid storage container 8 is connected to the water inlet via an inlet pipe, which is provided with a valve. The water outlet is connected to the liquid collecting container 9 via an outlet pipe. The liquid storage container 8 is located at a higher position than the liquid collecting container 9. The solution circulation device includes two sets of solution circulation assemblies, which include a supply bottle 22 for providing injection liquid, an inlet peristaltic pump 23 connected to the supply bottle 22 via an inlet pipe, a collection bottle 24 for collecting liquid, and a discharge peristaltic pump 25 connected to the collection bottle 24 via an outlet pipe. The inlet and outlet pipes of one set of solution circulation assemblies are connected to the permeable stone 15 on the base 11; the inlet and outlet pipes of the other set of solution circulation assemblies are connected to the permeable stone 15 on the upper sealing body 13. The differential pressure monitoring assembly is used to monitor the chemical osmotic pressure difference between the top and bottom ends of the sample 32 .

[0050] In the embodiment of the present application, the device for testing the blocking performance of the grouting junction entity throughout its life cycle adopts a gas phase method to control suction. Compared with the existing device that uses clay plates to control suction, the device has a fast suction loading speed and a wide suction control range, thereby realizing the unsaturated membrane effect test of the grouting junction entity within a wide suction range. In addition, the instrument and equipment are simple in composition, easy to operate, low in cost, small in space occupation, and have great value for wide promotion and application. The test device includes a gas phase suction control component, an integrated test chamber for curing and testing, and two sets of solution circulation components, which can control different curing conditions according to actual on-site conditions, realize unsaturated condition control, flow rate control, temperature control, and chemical environment control, and restore the actual curing conditions to a great extent, thereby ensuring the practicality of the test results.

[0051] In addition, the use of the grouting junction entity full life cycle resistance performance test device for testing is generally simple and easy. It can simultaneously control temperature, suction, groundwater flow rate, and water chemical environment, realizing the grouting junction entity maintenance and full life cycle resistance performance testing under simulated actual working conditions. At the same time, it has low maintenance costs and is applicable in actual projects. It has important engineering significance and theoretical research value.

[0052] Among them, the inner wall of the annular permeable stone 14 is flush with the inner wall of the rigid cylinder 10; the height of the annular permeable stone 14 is not less than one-third of the height of the rigid cylinder 10 and does not exceed one-half of the height of the rigid cylinder 10. During the test, the annular permeable stone 14 does not contact the base 11 and the permeable stone 15 on the upper sealing body 13.

[0053] In one embodiment, if Figure 1 As shown, the gas phase suction control component includes a gas circulation pump 1, a first liquid storage tank 2, a second liquid storage tank 3 and a valve. The outer wall of the rigid cylinder 10 is relatively provided with an air inlet and an air outlet. The air inlet and the air outlet are both connected to the annular permeable stone 14. The first liquid storage tank 2 is filled with a saturated salt solution. The air outlet end of the gas circulation pump 1 is introduced into the saturated salt solution. The first liquid storage tank 2, the second liquid storage tank 3 and the air inlet are connected in sequence through a pipeline 4. The air outlet is connected to the air inlet end of the gas circulation pump 1 through a pipeline 4, and the valve is set on the pipeline 4.

[0054] It can be understood that by filling different saturated salt solutions in the first liquid storage tank 2, different suction controls can be achieved, such as the suction corresponding to the saturated K2SO4 solution is 4.2MPa, and the suction corresponding to the saturated ZnSO4 solution is 12.6MPa.

[0055] In one embodiment, if Figure 1 As shown, the temperature control component includes a numerical control display screen 5 and a heating belt 7 and a temperature sensor 6 electrically connected to the numerical control display screen 5. The heating belt 7 is evenly wound on the outer wall of the rigid cylinder 10, and the temperature sensor 6 is embedded in the permeable stone 15 on the upper sealing body 13. The numerical control display screen 5 is used to set the heating temperature of the heating belt 7 as needed, and the temperature sensor 6 is used to detect the internal temperature of the accommodating cavity.

[0056] In one embodiment, if Figure 1 As shown, the pressure difference monitoring assembly includes a data acquisition instrument 21 and two pressure difference sensors 20 electrically connected to the data acquisition instrument 21 . The two pressure difference sensors 20 are respectively arranged in the permeable stone 15 on the base 11 and the permeable stone 15 on the upper sealing body 13 .

[0057] According to another aspect of the present application, an embodiment of the present application further provides a method for testing the blocking performance of a grouting junction entity throughout its life cycle. Based on the device for testing the blocking performance of a grouting junction entity throughout its life cycle provided by the present application, the method for testing the blocking performance of a grouting junction entity throughout its life cycle includes the following steps:

[0058] S1. Sample preparation: Prepare paste grouting material according to design requirements. Specifically, mix the various components of the composite grouting material and distilled water in a certain proportion and stir evenly into a paste;

[0059] S2. Loading: Loading sample 32 in the integrated test chamber for curing and testing;

[0060] S3. Simulating actual curing conditions: Adjust the temperature control assembly according to the actual site temperature environment to simulate the site temperature conditions; according to the actual site water chemistry, inject a certain concentration of salt solution into the supply bottle 22 of the two solution circulation assemblies to simulate the site groundwater conditions. According to the actual site groundwater flow rate, set the flow rate of the inlet peristaltic pump 23 and the outlet peristaltic pump 25 of the two solution circulation assemblies to simulate the site groundwater flow rate; finally, according to the actual site unsaturated state, prepare the saturated solution in the gas phase suction control assembly to simulate unsaturated curing conditions;

[0061] S4. Sample curing: Under the curing conditions set in step S3, curing for a certain number of days to complete the sample curing;

[0062] S5. Cleaning the solid: After the curing is completed, close the two sets of solution circulation components and the gas phase suction control component, replace the solution in the supply bottle 22 of the two sets of solution circulation components with distilled water, adjust the flow rate of the inlet peristaltic pump 23 and the outlet peristaltic pump 25, and continuously measure the conductivity of the liquid in the collection bottle 24. When the conductivity is less than half of the conductivity of the salt solution used in the supply bottle 22 of the solution circulation component in step S3, it is considered that the solid cleaning is complete;

[0063] S6. Conduct penetration testing using the penetration component;

[0064] S7. Conduct membrane effect tests under saturated / unsaturated conditions;

[0065] S8. Take out the knot and divide it into three parts. Use the filter paper method to test the suction of each part of the knot. Take the average value and record it as the actual suction s. s ;

[0066] S9. Change the test conditions and repeat the above test steps to carry out the grouting joint solid blocking performance test under different working conditions;

[0067] S10. Draw the relationship curve between curing time, actual suction, permeability coefficient and membrane efficiency coefficient, such as Figure 3 As shown, the blocking performance of grouting entities is comprehensively evaluated and predicted.

[0068] In the embodiment of the present application, the method for testing the blocking performance of the grouting junction entity throughout its life cycle targets the phase change characteristics (from paste to solid phase) that occur during the curing process of the grouting material, so that the test curing, saturated / unsaturated permeability test, and membrane effect test can all be completed in the same test chamber, which is simple to operate, improves the test efficiency, and saves costs; the method is generally simple and easy to implement, and can simultaneously control the temperature, suction, groundwater flow rate, and water chemical environment, thereby realizing the curing of the grouting junction entity and the blocking performance test throughout its life cycle under simulated actual working conditions, while having low maintenance costs and being applicable in actual projects, and having important engineering significance and theoretical research value.

[0069] Compared with traditional evaluation methods, this method comprehensively considers the permeability, suction and membrane effect of the grouting structure, and also introduces the time variable. By setting different curing times and controlling different curing environments, the evaluation of the blocking performance (suction, membrane effect and permeability) of the grouting structure throughout its life cycle under various working conditions is achieved.

[0070] In one embodiment, combining Figure 2 As shown, in step S2, loading the sample 32 into the integrated curing and testing chamber specifically includes:

[0071] The upper sealing body 13 is installed in the rigid cylinder 10, and the rigid cylinder 10 and the upper sealing body 13 are inverted together, and an inverted "T"-shaped top cover 31 with a specific height is inserted from the bottom of the rigid cylinder 10 to keep the upper sealing body 13 stationary in the rigid cylinder 10; filter paper 30 of corresponding size is placed on the surface of the permeable stone 15 on the upper sealing body 13, and then the paste grouting material prepared in advance is filled into the rigid cylinder 10 in multiple layers, and is continuously tamped with tools (such as glass rods) to expel bubbles; then, the upper surface of the paste grouting material is scraped flat with a scraper, and the filter paper 30 is placed on it. Next, the base 11 is turned upside down on the rigid cylinder 10 and fastened by the connecting assembly 12 (such as a bolt assembly), and finally the entire integrated curing and testing test chamber is quickly turned back to the right side.

[0072] By adopting the above-mentioned "inverted filling method", the paste grouting material can be filled more densely, ensuring the reliability of subsequent maintenance and testing.

[0073] Example 1:

[0074] Mix the grouting paste materials in a certain proportion and stir them evenly. Figure 2 Fill the sample into the integrated test chamber of curing and testing using the filling method shown, and ensure that the filling is dense.

[0075] After filling, follow Figure 1 As shown, connect all components of the device. Fill the supply bottles 22 of both solution circulation assemblies with distilled water. Start the inlet and outlet peristaltic pumps 23 and 25 and adjust the flow rate to 25.2 μL / min. Adjust the temperature control assembly to 20°C. Allow the device to stand under these conditions for 7 days.

[0076] After the curing is completed, the peristaltic pumps in the two sets of solution circulation components are closed, the valve on the water inlet pipe of the permeation component is opened, and the liquid in the liquid storage container 8 flows into the water inlet on the base 11 through the water inlet pipe, and the temperature is kept constant at 20°C. The permeation test is carried out, and the water output at different times is recorded using the liquid collecting container 9. The permeability coefficient is calculated using the following formula, which is the permeability of the grouting structure under the conditions of simulating static water and normal temperature curing.

[0077]

[0078] Where ΔQ is the difference in the flow rate of the seepage fluid between the top and bottom ends of the structure within Δt, A is the cross-sectional area of ​​the structure perpendicular to the direction of water flow, and I is the hydraulic gradient.

[0079] Example 2:

[0080] Mix the grouting paste materials in a certain proportion and stir them evenly. Figure 2 Fill the sample into the integrated test chamber of curing and testing using the filling method shown, and ensure that the filling is dense.

[0081] After filling, follow Figure 1 As shown, connect all components of the device. Fill the supply bottles 22 of both solution circulation assemblies with distilled water. Start the inlet and outlet peristaltic pumps 23 and 25 and adjust the flow rate to 25.2 μL / min. Adjust the temperature control assembly to 20°C. Allow the device to stand under these conditions for 7 days.

[0082] After curing was completed, the distilled water in the supply bottle 22 of the solution circulation assembly connected to the permeable stone 15 on the upper sealing body 13 was replaced with a 10mM manganese sulfate solution. The pressure differential monitoring assembly was turned on, and the inlet and outlet peristaltic pumps 23 and 25 were started at a flow rate of 25.2μL / min. The solution was circulated at the top and bottom ends of the structure. During the test, exudate from the top and bottom ends was collected, and the conductivity and concentration of the exudate were measured. Once the pressure differential monitoring assembly reading stabilized, the test was considered to have reached the stable stage under the action of the 10mM manganese sulfate solution.

[0083] Afterwards, the manganese sulfate solution was replaced with a higher concentration (20mM, 30mM, 40mM, and 50mM) until the pressure differential stabilized at the final concentration. The test concluded, completing the determination of the solid membrane efficiency coefficient of the grouting junction under normal curing and saturation conditions. The membrane effect coefficient was calculated using the following formula. This simulates the solid membrane effect of the grouting junction under static water and room temperature curing conditions.

[0084]

[0085] Where Δπ is the theoretical chemical osmotic pressure difference, which can be calculated by the Van't Hoff formula Δπ = vRTΔC, ΔP is the actual chemical osmotic pressure difference between the top and bottom ends of the junction, v is the total number of ions contained in the chemical formula of the electrolyte, and R is the universal gas constant (8.314 J·mol -1 ·K -1 ), T is the absolute temperature, and ΔC is the difference in chemical concentration between the top and bottom of the structure.

[0086] The range of membrane efficiency coefficient is 0<ω<1. ω=1 means no solute passes through; ω=0 means all solutes can pass through.

[0087] Example 3:

[0088] Mix the grouting paste materials in a certain proportion and stir them evenly. Figure 2 Fill the sample into the integrated test chamber of curing and testing using the filling method shown, and ensure that the filling is dense.

[0089] After filling, follow Figure 1 As shown, connect all components of the device. Fill the supply bottles 22 of both solution circulation assemblies with distilled water. Start the inlet and outlet peristaltic pumps 23 and 25 and adjust the flow rate to 25.2 μL / min. Adjust the temperature control assembly to 20°C. Allow the device to stand under these conditions for 14 days.

[0090] After the curing is completed, the distilled water in the supply bottle 22 in the solution circulation assembly connected to the permeable stone 15 on the upper sealing body 13 is replaced with a 10mM manganese sulfate solution, the pressure difference monitoring assembly and the gas phase suction control assembly are turned on, the suction is controlled to 4.2MPa, the liquid inlet peristaltic pump 23 and the liquid outlet peristaltic pump 25 are started and the flow rate is adjusted to 25.2μL / min, and the solution is circulated at the top and bottom ends of the structure.

[0091] During the test, the top and bottom exudates were collected, and the conductivity and concentration changes of the exudates were measured. When the reading of the pressure difference monitoring component is stable, it is considered that the test has reached the stable stage under the action of 10mM manganese sulfate solution. After that, the manganese sulfate solution with higher concentration (20mM, 30mM, 40mM, 50mM) is replaced until the pressure difference value under the last concentration condition is stable, and the unsaturated grouting solid membrane efficiency test is ended. Open the integrated test chamber for maintenance test, take out the solid, divide it into three parts, and use the filter paper method to test the suction of each solid, take the average value, and record it as the actual suction s s .

[0092] Repeat the above test steps to complete the grouting solid membrane effect test under 38MPa suction state.

[0093] The membrane efficiency coefficient is calculated using the following formula: It simulates the effect of the solid membrane formed by grouting at 14 days old under unsaturated room temperature conditions.

[0094]

[0095] Where Δπ is the theoretical chemical osmotic pressure difference, which can be calculated by the Van't Hoff formula Δπ = vRTΔC, ΔP is the actual chemical osmotic pressure difference between the top and bottom ends of the junction, v is the total number of ions contained in the chemical formula of the electrolyte, and R is the universal gas constant (8.314 J·mol -1 ·K -1 ), T is the absolute temperature, and ΔC is the difference in chemical concentration between the top and bottom of the structure.

[0096] Example 4:

[0097] like Figure 4 As shown, the grouting paste materials mixed in a certain proportion and stirred evenly are Figure 2 Fill the sample into the integrated test chamber of curing and testing using the filling method shown, and ensure that the filling is dense.

[0098] After filling, follow Figure 1 As shown, connect all components of the device. Inject sodium chloride solution into the supply bottles 22 of both solution circulation assemblies. Start the inlet peristaltic pump 23 and the outlet peristaltic pump 25 and adjust the flow rate to 100 μL / min. Adjust the temperature control assembly to 10°C. Turn on the differential pressure monitoring assembly and the gas phase suction control assembly, controlling the suction to 4.2 MPa. Curing is then carried out under these conditions for 90 days.

[0099] After curing is complete, shut off the peristaltic pumps and gas phase suction control components in both solution circulation assemblies. Replace the solution in the supply bottles 22 of both solution circulation assemblies with distilled water. Start the peristaltic pumps and adjust the flow rate to 100 μL / min. Continuously measure the conductivity of the effluent. Cleaning of the solids is considered complete when the conductivity is less than half the conductivity of the 10 mM manganese sulfate solution used in the test.

[0100] Afterwards, the valve on the water inlet pipe of the permeation component is opened, the temperature condition is set unchanged, and a permeation test is carried out. The water output of the liquid collecting container 9 at different times is recorded, and the permeability coefficient is calculated using the formula in Example 1.

[0101] Afterwards, the gas phase suction control component was started to conduct a test on the solid membrane effect of the unsaturated grouting structure under the infiltration of 10 mM manganese sulfate solution, and the membrane effect coefficient was calculated using the following formula.

[0102]

[0103] Where Δπ is the theoretical chemical osmotic pressure difference, which can be calculated using the Van't Hoff formula; ΔP is the actual chemical osmotic pressure difference between the top and bottom of the structure; and s is the loading suction.

[0104] After the differential pressure monitoring component shows stable readings, it has reached the stable stage under the action of 10mM manganese sulfate solution. After that, change to a higher concentration (20mM, 30mM, 40mM, 50mM) of manganese sulfate solution until the differential pressure value under the last concentration condition is stable, and then end the test. Take out the knot body, divide it into three parts, test the suction force of each knot body, and take the average value, which is recorded as the actual suction force s s That is, the permeability and membrane effect are comprehensively considered to evaluate the blocking performance of the grouting structure after 90 days of curing under extreme working conditions.

[0105]

[0106] Where Δπ is the theoretical chemical osmotic pressure difference, which can be calculated by the Van't Hoff formula, ΔP is the actual chemical osmotic pressure difference between the top and bottom of the structure, s s The actual suction force.

[0107] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A device for testing the blocking performance of a grouting joint throughout its entire life cycle, characterized in that: include: An integrated test chamber for curing and testing includes a rigid cylinder, a base, a connecting assembly, and an upper sealing body. The base is detachably mounted on the bottom of the rigid cylinder via the connecting assembly. The upper sealing body is slidingly and sealingly mounted within the rigid cylinder. The base, the interior of the rigid cylinder, and the upper sealing body enclose a chamber for accommodating paste grouting material. An annular permeable stone is embedded in the inner wall of the rigid cylinder, and permeable stones are embedded in the top of the base and the bottom of the upper sealing body. A gas phase suction control component is connected to two opposite sides of the annular permeable stone and controls the suction of the sample in the accommodating cavity by a gas phase method; a temperature control component, for controlling the internal temperature of the accommodating cavity; The infiltration assembly includes a liquid storage container and a liquid collection container. The bottom of the base is provided with a water inlet connected to the permeable stone thereon, and the top of the upper sealing body is provided with a water outlet connected to the permeable stone thereon. The bottom of the liquid storage container is connected to the water inlet via a water inlet pipe, and the water inlet pipe is provided with a valve. The water outlet is connected to the liquid collection container via an outlet pipe. The position of the liquid storage container is higher than that of the liquid collection container. A solution circulation device, comprising two sets of solution circulation components, each of which comprises a supply bottle for providing injection liquid, an inlet peristaltic pump connected to the supply bottle via an inlet pipe, a collection bottle for collecting liquid, and a discharge peristaltic pump connected to the collection bottle via an outlet pipe, wherein the inlet pipe and the outlet pipe of one set of the solution circulation components are connected to the permeable stone on the base; and the inlet pipe and the outlet pipe of the other set of the solution circulation components are connected to the permeable stone on the upper sealing body; and The differential pressure monitoring component is used to monitor the chemical osmotic pressure difference between the top and bottom ends of the sample.

2. The device for testing the blocking performance of grouting joints throughout their life cycle according to claim 1 is characterized in that: The gas phase suction control component includes a gas circulation pump, a first liquid storage tank, a second liquid storage tank and a valve. The outer wall of the rigid cylinder is relatively provided with an air inlet and an air outlet. The air inlet and the air outlet are both connected to the annular permeable stone. The first liquid storage tank is filled with a saturated salt solution. The air outlet end of the gas circulation pump is introduced into the saturated salt solution. The first liquid storage tank, the second liquid storage tank and the air inlet are connected in sequence through a pipeline. The air outlet is connected to the air inlet end of the gas circulation pump through a pipeline. The valve is arranged on the pipeline.

3. The device for testing the blocking performance of grouting structures throughout their entire life cycle according to claim 1, characterized in that: The inner side wall of the annular permeable stone is flush with the inner wall of the rigid cylinder; the height of the annular permeable stone is not less than one-third of the height of the rigid cylinder and does not exceed one-half of the height of the rigid cylinder. During the test, the annular permeable stone does not contact the base and the permeable stone on the upper sealing body.

4. The device for testing the blocking performance of grouting joints throughout their life cycle according to claim 1, characterized in that: The temperature control component includes a numerical control display screen and a heating belt and a temperature sensor electrically connected to the numerical control display screen. The heating belt is evenly wound around the outer wall of the rigid cylinder. The temperature sensor is embedded in the permeable stone of the upper sealing body. The numerical control display screen is used to set the heating temperature of the heating belt as needed, and the temperature sensor is used to detect the internal temperature of the accommodating cavity.

5. The device for testing the blocking performance of grouting structures throughout their life cycle according to claim 1 is characterized in that: The pressure difference monitoring assembly includes a data acquisition instrument and two pressure difference sensors electrically connected to the data acquisition instrument. The two pressure difference sensors are respectively arranged in the permeable stone on the base and the permeable stone on the upper sealing body.

6. A method for testing the blocking performance of a grouting junction entity throughout its life cycle, based on the device for testing the blocking performance of a grouting junction entity throughout its life cycle according to any one of claims 1 to 5, characterized in that: The method for testing the blocking performance of a grouting joint over its entire life cycle comprises the following steps: S1. Sample preparation: Prepare paste grouting material according to design requirements; S2. Loading: Loading the sample in the integrated test chamber for curing and testing; S3. Simulating actual curing conditions: Adjusting the temperature control assembly according to the actual site temperature environment to simulate the site temperature conditions; injecting a certain concentration of salt solution into the supply bottles of the two sets of the solution circulation assembly according to the actual site water chemistry to simulate the site groundwater conditions; setting the flow rates of the inlet and outlet peristaltic pumps of the two sets of the solution circulation assembly according to the actual site groundwater flow rate to simulate the site groundwater flow rate; finally, preparing a saturated solution in the gas phase suction control assembly according to the actual site unsaturated state to simulate unsaturated curing conditions; S4. Sample curing: Under the curing conditions set in step S3, curing for a certain number of days to complete the sample curing; S5. Cleaning the solid: After the curing is completed, close the two sets of the solution circulation components and the gas phase suction control component, replace the solution in the supply bottle of the two sets of the solution circulation components with distilled water, adjust the flow rate of the peristaltic pump for liquid inlet and outlet, and continuously measure the conductivity of the liquid in the collection bottle. When the conductivity is less than half the conductivity of the salt solution used in the supply bottle of the solution circulation component in step S3, the solid is considered to be cleaned; S6. Conduct a penetration test using the penetration component; S7. Conduct membrane effect tests under saturated / unsaturated conditions; S8. Take out the knot and divide it into three parts. Use the filter paper method to test the suction of each part of the knot. Take the average value and record it as the actual suction s. s ; S9. Change the test conditions and repeat the above test steps to carry out the grouting joint solid blocking performance test under different working conditions; S10. Draw the relationship curve between curing time, actual suction, permeability coefficient and membrane efficiency coefficient to comprehensively evaluate and predict the blocking performance of the grouting entity.

7. The method for testing the blocking performance of a grouting structure throughout its entire life cycle according to claim 6, wherein: In step S2, loading the sample into the integrated curing and testing chamber specifically includes: The upper sealing body is installed into the rigid cylinder, and the rigid cylinder and the upper sealing body are inverted together, and an inverted "T"-shaped top cover with a specific height is inserted from the bottom of the rigid cylinder to keep the upper sealing body stationary in the rigid cylinder; filter paper of corresponding size is placed on the surface of the permeable stone on the upper sealing body, and then the paste grouting material prepared in advance is filled into the rigid cylinder in layers, and is continuously tamped with tools to expel bubbles; then, the upper surface of the paste grouting material is scraped flat with a scraper, and filter paper is placed on it. Next, the base is turned upside down on the rigid cylinder and fastened through the connecting assembly. Finally, the entire integrated test chamber for maintenance and testing is quickly turned back to the upright position.

8. The method for testing the blocking performance of a grouting structure throughout its entire life cycle according to claim 6, wherein: In step S6, carrying out a penetration test using the penetration component specifically includes: Open the valve on the water inlet pipe of the permeation component, and the liquid in the liquid storage container flows into the water inlet on the base through the water inlet pipe. Set the temperature control component to keep the internal temperature of the accommodating chamber consistent with that in step S3. Use the liquid collection container to record the water output at different times, and calculate the permeability coefficient using the following formula: Where ΔQ is the difference in the flow rate of the seepage fluid between the top and bottom ends of the structure within Δt, A is the cross-sectional area of ​​the structure perpendicular to the direction of water flow, and I is the hydraulic gradient.

9. The method for testing the blocking performance of a grouting structure throughout its entire life cycle according to claim 6, wherein: In step S7, the membrane effect test under saturation state specifically includes: The distilled water in the supply bottle of the solution circulation assembly connected to the permeable stone on the upper sealing body was replaced with a 10 mM manganese sulfate solution. The pressure differential monitoring assembly was turned on, and the inlet and outlet peristaltic pumps in the two sets of the solution circulation assembly were started and the flow rate was adjusted to 25.2 μL / min. The solution was circulated at the top and bottom ends of the structure. During the test, the exudate from the top and bottom ends was collected, and the conductivity and concentration changes of the exudate were measured. After the pressure differential value monitored by the pressure differential monitoring assembly stabilized, it was considered that the test had reached a stable stage under the action of the 10 mM manganese sulfate solution. Afterwards, the manganese sulfate solution with higher concentration was replaced in sequence until the pressure difference value under the last concentration condition was stable, and the grouting solid membrane efficiency test under saturation was ended. The membrane effect coefficient was calculated using the following formula: Where Δπ is the theoretical chemical osmotic pressure difference, which can be calculated by Δπ = vRTΔC, ΔP is the actual chemical osmotic pressure difference between the top and bottom ends of the structure, v is the total number of ions contained in the chemical formula of the electrolyte, and R is the universal gas constant (8.314 J·mol -1 ·K -1 ), T is the absolute temperature, and ΔC is the difference in chemical concentration between the top and bottom of the structure.

10. The method for testing the blocking performance of a grouting structure throughout its entire life cycle according to claim 6, wherein: In step S7, performing a membrane effect test under an unsaturated state specifically includes: The distilled water in the supply bottle of the solution circulation assembly connected to the permeable stone on the upper sealing body was replaced with a 10 mM manganese sulfate solution. The pressure differential monitoring assembly and the gas phase suction control assembly were turned on, and the suction was controlled to 4.2 MPa. The inlet and outlet peristaltic pumps in the two sets of the solution circulation assemblies were started and the flow rate was adjusted to 25.2 μL / min. The solution was circulated at the top and bottom ends of the structure. During the test, exudate from the top and bottom ends was collected, and the conductivity and concentration changes of the exudate were measured. After the pressure differential value monitored by the pressure differential monitoring assembly stabilized, it was considered that the test had reached a stable stage under the action of the 10 mM manganese sulfate solution. Afterwards, the manganese sulfate solution with higher concentration was replaced in sequence until the pressure difference value under the last concentration condition was stable, and the grouting solid membrane efficiency test under the unsaturated state was ended. The membrane effect coefficient was calculated using the following formula: Wherein, Δπ is the theoretical chemical osmotic pressure difference, which can be calculated by the Van't Hoff formula, ΔP is the actual chemical osmotic pressure difference between the top and bottom ends of the structure, and s is the loading suction of the gas phase suction control component.

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