An experimental device and method for magnetic slurry crack grouting and filling

Abstract

The present invention provides an experimental device and method for grouting and filling of fissures with magnetic slurry, which comprises a steel truss, on which a fissure seepage visualization device and a camera to be tested are mounted, and the fissure seepage visualization device is connected to the bottom slurry outlet of a multifunctional pressure grouting pot through a grouting pipe, and the top of the multifunctional pressure grouting pot is connected to a pressure pipe, and the pressure pipe is connected to an air pump. The flow trajectory and filling area law of magnetic slurry under different grouting pressures are established, and a radial diffusion model of fissure slurry grouting is established; slurry ratio parameters are provided for different forms of fissure grouting repair projects, so as to achieve better filling inside the cracks, ensure the repair quality and reduce the cost at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of rock crack experiments, and in particular relates to an experimental device and method for magnetic slurry crack grouting and filling. Background Art

[0002] In recent years, with the continuous development of domestic infrastructure projects, the construction scale of various types of tunnel (hole) projects has also continued to expand. In geotechnical engineering such as mining, water conservancy and hydropower, tunnels, and slope reinforcement, cracks have an important impact on the stability of rock engineering. On the one hand, rock cracks are one of the important causes of water damage in underground projects. On the other hand, the existence of cracks also greatly reduces the strength of the rock mass. Grouting to fill cracks can not only effectively prevent and control engineering water damage, but also improve the integrity of the surrounding rock, and the reinforcement effect on the broken rock mass is very obvious. During the grouting process, the diffusion law of the slurry in the cracks has a decisive and important influence on the water blocking and surrounding rock reinforcement effects.

[0003] Therefore, this field is in great need of studying the diffusion morphology and influencing factors of slurry in cracks, and conducting fracture grouting simulation tests under complex conditions and establishing a fracture grouting radial diffusion model based on this is an effective research method. The following factors should be considered in establishing a fracture grouting radial diffusion model: the stress state of the fracture, fracture deformation and relative shear displacement, fracture surface contact area, slurry viscosity, fracture opening, grouting pressure, fracture roughness, fracture connectivity, fracture groundwater pressure and flow, whether the fracture surface is open, and various construction factors. The key technology is the realization of test boundary conditions, namely load, displacement boundary conditions and seepage boundary conditions. Due to the limitations of test conditions, especially in terms of confining pressure loading, controllable fracture displacement, penetration sealing means, and visualization, there are still limitations in the research on rock fracture grouting diffusion tests and test methods under complex conditions in China, and related test equipment is still relatively lacking. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an experimental device and method for magnetic slurry fissure grouting and filling, so as to establish the flow trajectory and filling area law of magnetic slurry under different grouting pressures, and establish a radial diffusion model of fissure slurry grouting; provide slurry ratio parameters for different forms of fissure grouting repair projects, achieve better filling of the inside of the cracks, ensure the quality of repair while reducing costs.

[0005] In order to realize the above-mentioned technical features, the object of the present invention is achieved as follows: an experimental device for magnetic slurry fissure grouting and filling, which includes a steel truss, on which are mounted a fissure seepage visualization device and a camera to be tested, the fissure seepage visualization device is connected to the bottom slurry outlet of a multifunctional pressure grouting jar through a grouting pipe, the top of the multifunctional pressure grouting jar is connected to a pressure pipe, and the pressure pipe is connected to an air pump.

[0006] The steel truss is a basic component of the experimental device and is made of stainless steel; it includes a base and a camera fixing frame; the base is used to build and place the fracture seepage visualization device, and the camera fixing frame is used to place the camera.

[0007] The four corners of the edge of the base are provided with bolt holes, and the base is fixed by four long bolts; and the inclination angle of the fracture seepage visualization device is changed by adjusting the positions of the nuts in the four long bolts, so as to realize the magnetic slurry fracture seepage experiment at different inclination angles; before adjustment, an angle measuring instrument is placed on the base to ensure the accuracy of the inclination angle adjusted by the base.

[0008] The fracture seepage visualization device is formed by fixing and bonding two acrylic plates of the same size, a rubber sealing strip for sealing is arranged between the two acrylic plates, and the opening between the acrylic plates is adjusted by the rubber sealing strip, thereby realizing fracture seepage visualization experiments with different openings.

[0009] The fracture seepage visualization device has reserved holes for the arrangement of magnetic bars inside, three grouting holes with equal spacing are reserved at a certain distance from the right side of the magnetic bar, and a water injection hole is reserved in the middle position on the opposite side of the grouting hole, and the diameters of the grouting holes and the water injection holes are the same as the radius of the magnetic bar.

[0010] The camera is placed on a camera fixing frame, and the focal length of the camera can be adjusted so that the penetration and diffusion process of the magnetic slurry can be clearly recorded during the experiment.

[0011] A pressure control valve is provided at the outlet of the air pump. The pressure control valve is equipped with a pressure digital control meter. The grouting pressure is accurately controlled by adjusting the pressure value of the control meter to ensure the stability of the grouting pressure and enhance the accuracy of the experiment.

[0012] The multifunctional pressure grouting device is connected to the air pump as a whole by a plastic hose, so that the air pressure inside the two is the same; the multifunctional pressure grouting device is equipped with an air pressure display gauge and a grouting control valve, and the internal pressure condition is determined by observing the numbers on the air pressure display gauge.

[0013] The interior of the multifunctional pressure grouting pot is injected with magnetic slurry through the funnel at its top. The magnetic slurry is prepared by mixing cement, water, magnetic powder, water-based epoxy resin and asphalt in a set ratio. The specific mixing ratio is determined according to experimental requirements.

[0014] The experimental method for conducting magnetic slurry fissure grouting and filling using the experimental device comprises the following steps:

[0015] Step 1. Material preparation: steel truss, base, camera fixing frame, magnetic slurry, fracture seepage visualization device, acrylic plate, rubber sealing strip, air pump, multi-function pressure grouting pot, magnetic rod, camera, grouting control valve;

[0016] Step 2: Make magnetic slurry: Determine the weight of cement, water, water-based epoxy resin, magnetic powder and asphalt materials according to the ratio of magnetic slurry, use an electronic balance to weigh the corresponding weight of materials and put them into a steel cylinder, and then turn on the power of the stirrer to stir them thoroughly;

[0017] Step 3: Install the fracture seepage visualization device: Place the magnetic bar in the magnetic bar hole reserved inside the acrylic plate and place two silicone gaskets on the other side, then place another acrylic plate to overlap the two plates, and use a rubber sealing strip to fix and bond them into a whole;

[0018] Step 4: Adjust the base: Place the angle measuring instrument on the base, adjust the position of the nuts in the four long bolts on the edge of the base to change the inclination angle of the base, and adjust the inclination angle of the base to the angle required for the experiment by observing the reading of the angle measuring instrument;

[0019] Step 5: Experimental device construction: Place the fracture seepage visualization device on the base and fix it, and place the camera in the camera holder, and then adjust the focal length of the camera so that it can clearly record the infiltration and diffusion process of the magnetic slurry area in the experiment;

[0020] Step 6: Connect the multifunctional pressure grouting pot with the air pump by using a plastic hose to form a whole. The outlets of the air pump and the multifunctional pressure grouting pot are both provided with pressure control valves. The valves have a pressure digital display gauge, which can accurately control the grouting pressure and ensure the stability of the pressure.

[0021] Step 7: Pour the prepared magnetic slurry into the multifunctional pressure grouting pot, turn on the air pump to compress the air and the camera switch to adjust the internal air pressure of the multifunctional pressure grouting pot to the experimental air pressure through the regulating valve and conduct the experiment;

[0022] Step 8: Clean and install the fracture seepage visualization device after the experiment, change the grouting pressure and magnetic rod strength, and repeat the above experimental steps.

[0023] The present invention has the following beneficial effects:

[0024] 1. The strength of the magnetic rod, the distance between the grouting hole and the magnetic rod, the ratio of the magnetic slurry and the grouting pressure used in the present invention are all variable. The method of controlling variables is used to carry out relevant experiments, the purpose of which is: ① By observing the flow trajectory and diffusion area law of the magnetic slurry under the action of magnetic rods with different magnetic field strengths, the influence range index of magnetic rods with different magnetic field strengths on the slurry is obtained, so that the magnetic rods can be reasonably arranged in the crack repair project to ensure the quality of the project and reduce the cost ② For fine cracks, according to the influence range of the magnetic field, small magnetic rods or magnetic sheets can be arranged inside the cracks for grouting repair to avoid disturbance of the structure caused by drilling ③ Determine the parameters affecting the magnetic slurry by the grouting pressure and grouting position, and guide and improve the existing grouting construction process.

[0025] 2. The present invention obtains the grouting rules of magnetic mortars of different consistencies in cracks through grouting experiments at different openings and roughnesses, and provides slurry ratio parameters for different forms of crack grouting repair projects, so that the inside of the cracks is fully filled with slurry to ensure the integrity of the project;

[0026] 3. The present invention uses independently developed magnetic slurry to carry out crack grouting filling research, the purpose of which is to: ① improve the fluidity of the slurry, so that small cracks can be better grouting and filling repair ② realize anti-gravity grouting repair ③ improve the anti-dispersion ability and drainage ability of the slurry underwater, and realize underwater grouting to repair cracks;

[0027] 4. The present invention utilizes the image self-recognition technology of the camera to capture in real time the law of the diffusion area of ​​the magnetic slurry under different magnetic field intensities and different grouting pressures in the fracture seepage visualization experiment, which is convenient for in-depth research and analysis of the experiment;

[0028] 5. The present invention uses a rubber sealing strip to fix and bond the acrylic plate, which facilitates the disassembly and installation of the fracture seepage visualization device during the experiment, achieves the effect of sealing, and avoids the cumbersome process of sealing, which is convenient for implementation and speeds up the progress of the experiment;

[0029] 6. The fixed base used in the present invention can flexibly change the inclination angle of the base by adjusting the position of the nuts in the four long bolts on its edge, and at the same time use an angle measuring instrument to measure its inclination, thereby improving the accuracy of the experiment and realizing the visualization experiment of fracture seepage under different inclination angles;

[0030] 7. The present invention provides grouting pressure through an air pump, thereby ensuring the stability of the grouting pressure; at the same time, a pressure control valve is arranged at its outlet, and the grouting pressure can be accurately controlled by adjusting the value of the digital display meter of the pressure control valve;

[0031] 8. The multifunctional pressure grouting pot of the present invention is connected to the air pump by a plastic hose, which ensures that the internal pressure is the same as the grouting pressure set by the air pump, thereby ensuring the accuracy of the experiment; at the same time, the multifunctional pressure grouting pot is convenient for grouting and cleaning, thus reducing the workload of the experiment;

[0032] 9. The present invention is simple to operate and low in cost, and has broad practical significance and application prospects in crack repair projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0034] Figure 1 It is a schematic diagram of the overall device of the present invention.

[0035] Figure 2 This is a schematic diagram of the fracture seepage visualization device of the present invention.

[0036] Figure 3 It is a cross-sectional schematic diagram of the fracture seepage visualization device of the present invention.

[0037] In the figure: steel truss 1, base 2, camera fixing bracket 3, magnetic slurry 4, fracture seepage visualization device 5, acrylic plate 6, rubber sealing strip 7, air pump 8, multifunctional pressure grouting 9, magnetic rod 10, camera, valve 12. DETAILED DESCRIPTION

[0038] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0039] Embodiment 1:

[0040] See also Figure 1-3 , an experimental device for magnetic slurry fissure grouting and filling, comprising a steel truss 1, on which a fissure seepage visualization device 5 and a camera to be tested are mounted, the fissure seepage visualization device 5 is connected to the bottom slurry outlet of a multifunctional pressure grouting pot 9 through a grouting pipe, the top of the multifunctional pressure grouting pot 9 is connected with a pressure pipe, and the pressure pipe is connected to an air pump 8. Through the above experimental device, the flow trajectory and filling area law of the magnetic slurry under different grouting pressures are established, and a radial diffusion model of fissure slurry grouting is established; slurry ratio parameters are provided for different forms of fissure grouting repair projects, so as to achieve better filling inside the cracks, ensure the repair quality and reduce the cost.

[0041] Furthermore, the steel truss 1 is a basic component of the experimental device, which is made of stainless steel; it includes a base 2 and a camera fixing frame 3; the base 2 is used to build and place the fracture seepage visualization device 5, and the camera fixing frame 3 is used to place the camera. The use of stainless steel ensures the quality of the truss while reducing the weight of the device, making it convenient to conduct the experiment.

[0042] Furthermore, bolt holes are provided at the four corners of the edge of the base 2, and the base 2 is fixed by four long bolts; and the inclination angle of the fracture seepage visualization device 5 is changed by adjusting the positions of the nuts in the four long bolts, so as to realize the magnetic slurry fracture seepage experiment at different inclination angles; before adjustment, an angle measuring instrument is placed on the base 2 to ensure the accuracy of the adjusted inclination angle of the base 2.

[0043] Furthermore, the fissure seepage visualization device 5 is formed by fixing and bonding two acrylic plates 6 of the same size, and a rubber sealing strip 7 for sealing is arranged between the two acrylic plates 6, and the opening between the acrylic plates 6 is adjusted by the rubber sealing strip 7, thereby realizing the fissure seepage visualization experiment with different openings. The bonding and fixation between the two acrylic plates 6 is realized by the rubber sealing strip 7.

[0044] Furthermore, the fissure seepage visualization device 5 has a reserved hole for arranging the magnetic rod 10, and three grouting holes with the same spacing are reserved at a certain distance to the right of the magnetic rod 10, and a water injection hole is reserved in the middle position on the opposite side of the grouting hole, and the diameters of the grouting hole and the water injection hole are the same as the radius of the magnetic rod. The magnetic rod 10 can be used to control the penetration process of the magnetic slurry 4.

[0045] Furthermore, the camera is placed on the camera fixing frame 3, and the focal length of the camera can be adjusted so that the infiltration and diffusion process of the magnetic slurry 4 can be clearly recorded in the experiment, and then the change process of the corresponding magnetic slurry 4 in the seepage of cracks with different openings is studied.

[0046] Furthermore, a pressure control valve is provided at the outlet of the air pump 8, and the pressure control valve is equipped with a pressure digital control meter. The grouting pressure can be accurately controlled by adjusting the pressure value of the control meter to ensure the stability of the grouting pressure and enhance the accuracy of the experiment.

[0047] Furthermore, the multifunctional pressure grouting pot 9 is connected to the air pump 8 as a whole by a plastic hose, so that the air pressure inside the two is the same; the multifunctional pressure grouting pot 9 is equipped with an air pressure display gauge and a grouting control valve 12, and the internal pressure conditions are determined by observing the numbers on the air pressure display gauge.

[0048] Furthermore, the interior of the multifunctional pressure grouting pot 9 is injected with magnetic slurry 4 through the funnel at the top thereof. The magnetic slurry 4 is mixed with cement, water, magnetic powder, water-based epoxy resin and asphalt in a set ratio. The specific mixing ratio is determined according to experimental requirements.

[0049] Embodiment 2:

[0050] The experimental method for conducting magnetic slurry fissure grouting and filling using the experimental device comprises the following steps:

[0051] Step 1. Material preparation: steel truss 1, base 2, camera fixing frame 3, magnetic slurry 4, fracture seepage visualization device 5, acrylic plate 6, rubber sealing strip 7, air pump 8, multifunctional pressure grouting 9, magnetic rod 10, camera, grouting control valve 12;

[0052] Step 2: Prepare magnetic slurry 4: Determine the weight of cement, water, water-based epoxy resin, magnetic powder and asphalt materials according to the proportion of magnetic slurry 4, use an electronic balance to weigh the corresponding weight of the materials and put them into a steel cylinder, and then switch on the stirrer to stir them fully;

[0053] Step 3: Install the fracture seepage visualization device 5: Place the magnetic bar 10 in the magnetic bar hole reserved inside the acrylic plate 6 and place two silicone gaskets on the other side, then place another acrylic plate so that the two plates overlap, and use the rubber sealing strip 7 to fix and bond them into a whole;

[0054] Step 4: Adjust base 2: Place the angle measuring instrument on the base, adjust the position of the nuts in the four long bolts on the edge of the base to change the inclination angle of base 2, and adjust the base inclination angle to the angle required for the experiment by observing the reading of the angle measuring instrument;

[0055] Step 5: Experimental device construction: Place the fracture seepage visualization device 5 on the base and fix it, and place the camera in the camera holder 3, and then adjust the focal length of the camera so that it can clearly record the infiltration and diffusion process of the magnetic slurry area in the experiment;

[0056] Step 6: Connect the multifunctional pressure grouting pot with the air pump 8 as a whole by using a plastic hose. The outlets of the air pump 8 and the multifunctional pressure grouting pot 9 are both provided with a pressure control valve. The valve has a pressure digital display meter, which can accurately control the grouting pressure and ensure the stability of the pressure.

[0057] Step 7: Pour the prepared magnetic slurry 4 into the multifunctional pressure grouting pot 9, and turn on the air pump 8 to compress the air and the camera switch to adjust the internal air pressure of the multifunctional pressure grouting pot to the experimental air pressure through the regulating valve and conduct the experiment;

[0058] Step 8: Clean and install the fracture seepage visualization device after the experiment, change the grouting pressure and the strength of the magnetic rod 10, and repeat the above experimental steps.

Claims

1. An experimental method for magnetic slurry fracture grouting and filling, comprising an experimental device for magnetic slurry fracture grouting and filling, characterized in that: The experimental device comprises a steel truss (1), on which a fracture seepage visualization device (5) and a camera to be tested are mounted, the fracture seepage visualization device (5) being connected to a bottom grout outlet of a multifunctional pressure grouting pot (9) via a grouting pipe, the top of the multifunctional pressure grouting pot (9) being connected to a pressure pipe, and the pressure pipe being connected to an air pump (8); The steel truss (1) is a basic component of the experimental device and is made of stainless steel. It comprises a base (2) and a camera fixing frame (3). The base (2) is used to build and place the fracture seepage visualization device (5), and the camera fixing frame (3) is used to place a camera. Bolt holes are arranged at the four corners of the edge of the base (2), and the base (2) is fixed by four long bolts; the inclination angle of the fracture seepage visualization device (5) is changed by adjusting the positions of the nuts in the four long bolts, so as to realize the magnetic slurry fracture seepage experiment at different inclination angles; before adjustment, an angle measuring instrument is placed on the base (2) to ensure the accuracy of the inclination angle adjusted by the base (2); The fracture seepage visualization device (5) is formed by fixing and bonding two acrylic plates (6) of the same size, a rubber sealing strip (7) for sealing is provided between the two acrylic plates (6), and the opening between the acrylic plates (6) is adjusted by the rubber sealing strip (7), thereby realizing fracture seepage visualization experiments with different openings; The fissure seepage visualization device (5) has reserved holes for arranging the magnetic rod (10) inside, three grouting holes with equal spacing are reserved at a certain distance to the right of the magnetic rod (10), and a water injection hole is reserved in the middle of the opposite side of the grouting hole, and the diameters of the grouting hole and the water injection hole are the same as the radius of the magnetic rod; The camera is placed on a camera fixing frame (3), and the focal length of the camera can be adjusted so that the camera can clearly record the penetration and diffusion process of the magnetic slurry (4) during the experiment; The outlet of the air pump (8) is provided with a pressure control valve, which is equipped with a pressure digital control meter. The grouting pressure is accurately controlled by adjusting the pressure value of the control meter, thereby ensuring the stability of the grouting pressure and enhancing the accuracy of the experiment. The multifunctional pressure grouting pot (9) is connected to the air pump (8) by a plastic hose to form a whole, so that the air pressure inside the two is the same; the multifunctional pressure grouting pot (9) is equipped with an air pressure display gauge and a grouting control valve (12), and the pressure inside the pot can be determined by observing the numbers on the air pressure display gauge; The multifunctional pressure grouting pot (9) is filled with magnetic slurry (4) through a funnel at the top thereof. The magnetic slurry (4) is prepared by mixing cement, water, magnetic powder, water-based epoxy resin and asphalt in a set ratio. The specific mixing ratio is determined according to experimental requirements. The experimental method comprises the following steps: Step 1. Material preparation: steel truss (1), base (2), camera fixing frame (3), magnetic slurry (4), fracture seepage visualization device (5), acrylic plate (6), rubber sealing strip (7), air pump (8), multifunctional pressure grouting pot (9), magnetic rod (10), camera, grouting control valve (12); Step 2: Prepare magnetic slurry (4): Determine the weight of cement, water, water-based epoxy resin, magnetic powder and asphalt materials according to the proportion of magnetic slurry (4), weigh the corresponding weight of materials using an electronic balance and put them into a steel cylinder, and then switch on the stirrer to stir them thoroughly; Step 3: Install the fracture seepage visualization device (5): Place the magnetic bar (10) in the magnetic bar hole reserved inside the acrylic plate (6) and place two silicone gaskets on the other side, then place another acrylic plate so that the two plates overlap, and use a rubber sealing strip (7) to fix and bond them into a whole; Step 4: Adjust the base (2): Place the angle measuring instrument on the base, adjust the position of the nuts in the four long bolts on the edge of the base to change the inclination angle of the base (2), and adjust the base inclination angle to the angle required for the experiment by observing the reading on the angle measuring instrument; Step 5: Setting up the experimental device: Place the fracture seepage visualization device (5) on the base and fix it, and place the camera in the camera holder (3), and then adjust the focal length of the camera so that it can clearly record the permeation and diffusion process of the magnetic slurry area during the experiment; Step 6: The multifunctional pressure grouting pot is connected to the air pump (8) by a plastic hose to form a whole. The outlets of the air pump (8) and the multifunctional pressure grouting pot (9) are both provided with a pressure control valve, and the valve has a pressure digital display meter, which can accurately control the grouting pressure and ensure the stability of the pressure; Step 7: Pour the prepared magnetic slurry (4) into the multifunctional pressure grouting pot (9), and turn on the air pump (8) to compress the air and the camera switch to adjust the internal air pressure of the multifunctional pressure grouting pot to the experimental air pressure through the regulating valve and conduct the experiment; Step 8: Clean and install the fracture seepage visualization device after the experiment, change the grouting pressure and the strength of the magnetic rod (10), and repeat the above experimental steps.

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