Deeply-buried loose water-containing sand layer permeation grouting diffusion simulation test device and method

Abstract

The invention discloses a deeply-buried loose water-containing sand layer permeation grouting diffusion simulation test device and method, and relates to the field of geotechnical engineering and underground engineering, the deeply-buried loose water-containing sand layer permeation grouting diffusion simulation test device comprises a modular test platform, a water supply assembly, a grouting assembly and a monitoring assembly, and the modular test platform comprises a test box body and an air bag assembly; a water injection port and a water outlet in the water supply assembly are formed in the two sides and the bottom of the test box body, a grouting pipe in the grouting assembly is arranged in the middle of a top air bag in the air bag assembly, and the displacement sensors are arranged on the inner side of a top plate and the inner sides of left and right side plates of the test box body. According to the deeply-buried loose water-containing sand layer permeation grouting diffusion simulation test device and method, the test platform is convenient to assemble, the operation process is simple, the device and method have important significance on improvement of the grouting transformation effect of a water-rich sand layer on site, and popularization and application of grouting transformation of a target sand layer in engineering practice are facilitated.

Description

Technical Field

[0001] This invention relates to the fields of geotechnical engineering and underground engineering, and in particular to a device and method for simulating the diffusion of infiltration grouting in deeply buried loose water-bearing sand layers. Background Technology

[0002] Currently, the mining area is located in a deep-buried, thick, loose layer with thin bedrock. The overlying Neogene loose layer has a high water content and high water pressure, and the sand layer is fine and has good fluidity. In some mining areas, the bedrock thickness does not meet or just meets the design standard, making it extremely easy to cause water inrush and sand collapse safety accidents under the influence of mining. At present, grouting is mostly used to reinforce and modify such strata to reduce the water content in the sand layer and fill the pores inside the sand layer, thereby achieving the effect of modifying the water-bearing sand layer.

[0003] Grouting for sand layer restoration mostly employs chemical grouting materials, which offer good fluidity, low initial viscosity, high bonding with sand, and excellent impermeability after consolidation. However, deep sand layers are often difficult to conceal, making real-time monitoring of grout diffusion paths and ranges challenging. Furthermore, the combined effects of high water pressure (>10MPa) and high ground stress (depth >500m) on grout diffusion resistance and sand layer deformation lack quantitative characterization. Traditional sampling and testing methods cannot reflect the pore evolution and spatiotemporal distribution of consolidation strength throughout the grouting process. Existing simulation devices are mostly designed for shallow sand layers and lack integrated multi-physics monitoring modules, making it difficult to reproduce the actual working conditions of deeply buried strata. Summary of the Invention

[0004] The purpose of this invention is to provide a simulation test device and method for permeation grouting diffusion in deeply buried loose water-bearing sand layers. The test platform is easy to assemble and the operation process is simple. It is of great significance for improving the grouting modification effect of water-rich sand layers in the field and is conducive to the promotion and application of grouting modification of target sand layers in engineering practice.

[0005] To achieve the above objectives, the present invention provides a simulation test device and method for permeation grouting diffusion in deeply buried loose water-bearing sand layers, including a modular test platform, a water supply component, a grouting component, and a monitoring component. The modular test platform includes a test chamber and an airbag component. The test chamber is provided with water inlets and outlets in the water supply component on both sides and the bottom. The airbag component has a grouting pipe in the middle of the top airbag. Displacement sensors are arranged inside the top plate and the left and right side plates of the test chamber.

[0006] Preferably, the test chamber includes a top plate, left and right side plates, a base, and front and rear baffles. The outside of the test chamber is connected and fixed with a stainless steel frame. The front and rear baffles and left and right side plates are made of plexiglass panels. The plexiglass panels and the stainless steel frame are fixedly connected by side bolts. The interior of the test chamber is filled with a simulated sand layer, a middle partition, and a tenon and mortise structure. The tenon and mortise structure is equipped with a partition limiter. The top plate is fixedly connected to the base by bolts and rods. A fixing bolt is set in the center of the bottom plate of the test chamber.

[0007] Preferably, the airbag includes a top airbag, a top airbag inflation tube, side airbags, and side airbag inflation tubes. The top airbag is attached to the bottom of the top plate, and the top airbag inflation tube is fixedly installed on the top plate. The side airbags are located between the left and right side plates and the simulated sand layer, and are attached to the inside of the left and right side plates. The side airbag inflation tubes are fixedly installed on the left and right side plates. Pressure sensors are provided on both the top airbag inflation tube and the side airbag inflation tube.

[0008] Preferably, the water supply assembly includes an inlet and an outlet, and a flow meter and a check valve are installed on both the inlet and the outlet.

[0009] Preferably, the grouting assembly includes a grouting pipe, which has openings on both sides of the pipe body.

[0010] Preferably, the monitoring components include a pore water pressure gauge, a pressure sensor, and a displacement sensor, wherein the pressure sensor, the displacement sensor, the pore water pressure gauge, and the flow meter of the water supply component are respectively connected to a wireless signal receiving device.

[0011] Preferably, a method for simulating the diffusion of infiltration grouting in deeply buried loose water-bearing sand layers includes the following steps: Step S1: Assemble the test chamber and prepare the sand layer; Assemble the test chamber by connecting and fixing the top plate, left and right side plates, base, and front and rear baffles with stainless steel frames and bolts to form a detachable test chamber; install the middle partition and mortise and tenon structure, and divide the internal space of the test chamber into multiple target areas by sliding the middle partition. To prepare a simulated sand layer, sand is filled into the test chamber from the top to form a simulated sand layer. Step S2: Simulate the stress environment of the sand layer; Install the airbag assembly, attach the top airbag to the bottom of the top plate and the side airbags to the inside of the left and right side plates, and connect to the external air source through the inflation tubes of the top and side airbags; apply confining pressure, and according to the underground burial depth of the simulated sand layer, inflate the top and side airbags to compress the simulated sand layer, simulating the underground stress environment at different burial depths. Step S3: Simulate a water-rich environment; The water supply system is activated, injecting water into the simulated sand layer through the injection port, with excess water discharged from the outlet. Flow meters and check valves at both the injection and outlet are used to simulate water-rich conditions at different burial depths. Initial parameters are monitored: the initial pore water pressure in the sand layer is monitored using a pore water pressure gauge, and the initial water injection volume is recorded using a flow meter. Step S4: Perform grouting operation; Install the grouting assembly, ensuring the grouting pipe is fixed in the middle of the top airbag and aligned with the target area of ​​the simulated sand layer; perform grouting by injecting grout into the simulated sand layer through the grouting pipe, ensuring the grout spreads evenly through the opening structure of the grouting pipe, and simultaneously start recording basic parameters such as grouting time and grouting volume.

[0012] Step S5: Real-time monitoring and data acquisition; The monitoring components are activated to collect data in real time using pressure sensors, pore water pressure gauges, displacement sensors, and flow meters of the water supply components placed at different layers of the simulated sand layer. Data is transmitted from each sensor and flow meter to a signal collection device via a wireless signal receiving device, and then fed back to a data analysis device. Step S6: Data processing and result analysis; Data analysis involves processing collected data such as pressure, displacement, pore water pressure, and flow rate using software within the data analysis device, and outputting detection results. Pattern summarization involves analyzing the diffusion patterns of the grout, the spatiotemporal evolution of sand layer porosity, and the consolidation characteristics of the grout based on the data results, to draw relevant conclusions regarding the diffusion of infiltration grout in deeply buried loose, water-bearing sand layers.

[0013] Therefore, the purpose of this invention is to provide a simulation test device and method for permeation grouting diffusion in deeply buried loose water-bearing sand layers. The test platform is easy to assemble and the operation process is simple. It is of great significance for improving the grouting modification effect of water-rich sand layers in the field and is conducive to the promotion and application of grouting modification of target sand layers in engineering practice. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of a deep-buried loose water-bearing sand layer infiltration grouting diffusion simulation test device according to the present invention; Figure 2 This is a schematic diagram of the front and rear baffles of a deep-buried loose water-bearing sand layer infiltration grouting diffusion simulation test device according to the present invention; Figure 3 This is a schematic diagram of the middle partition plate of a deep-buried loose water-bearing sand layer infiltration grouting diffusion simulation test device according to the present invention; Figure 4 This is a cross-sectional view of a deep-buried, loose, water-bearing sand layer infiltration grouting diffusion simulation test device according to the present invention; Figure 5 This is a flowchart of a method for simulating the diffusion of infiltration grouting in a deeply buried, loose, water-bearing sand layer according to the present invention.

[0015] Figure Labels 1. Top plate; 2. Left and right side plates; 3. Base; 4. Front and rear baffles; 5. Top airbag inflation pipe; 6. Grouting pipe; 7. Top airbag; 8. Side airbags; 9. Water inlet; 10. Side airbag inflation pipe; 11. Partition limiter; 12. Mortise and tenon structure; 13. Fixing bolts; 14. Middle partition; 15. Water outlet; 16. Simulated sand layer; 17. Side bolts; 18. Bolt connecting rod; 19. Displacement sensor; 20. Pore water pressure gauge; 21. Pressure sensor. Detailed Implementation

[0016] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0018] Example 1 like Figures 1-4 As shown, the present invention provides a simulation test device for permeation grouting diffusion in deeply buried loose water-bearing sand layers, including a modular test platform, a water supply component, a grouting component, and a monitoring component. The modular test platform includes a test chamber and an airbag component. The test chamber is provided with water inlets 9 and outlets 15 in the water supply component on both sides and the bottom. The airbag component has a grouting pipe 6 in the middle of the top airbag 7. Displacement sensors 19 are arranged inside the top plate 1 and the left and right side plates 2 of the test chamber. The displacement sensors 19 detect the distance that the top and side surfaces of the sand layer expand outward during the grouting process.

[0019] The test chamber includes a top plate 1, left and right side plates 2, a base 3, and front and rear baffles 4. The overall structure is branched for easy disassembly and assembly. A stainless steel frame is used for external connection and fixation. The front and rear baffles 4 and left and right side plates 2 are made of transparent acrylic sheets, which are fixed to the stainless steel frame with side bolts. The interior of the test chamber is filled with simulated sand layer 16, a middle partition 14, and a tenon and mortise structure 12. A partition limiter 11 is installed on the tenon and mortise structure 12. The middle partition 14 divides the sand layer into multiple target sand layers. Sand is filled into the chamber from the top to form the simulated sand layer 16. A fixing bolt 13 is installed at the center of the bottom plate of the test chamber. The middle partition 14 slides within the test chamber, dividing the sand layer into multiple target sand layers. The top of the test chamber is sealed by the top plate 1, which is fixedly connected to the base 3 by bolts and rods 18, forming a sealed space. Based on the simulated underground layer 16, the confining pressure of the sand layer was determined. The sand layer inside the test chamber was compressed to different degrees by inflating the top airbag 7 and the side airbag 8 to simulate the stress environment of sand layers at different underground burial depths.

[0020] The airbag system includes a top airbag 7, a top airbag inflation tube 5, side airbags 8, and side airbag inflation tubes 10. The top airbag 7 is attached below the top plate 1 and is slightly smaller than the area of ​​the top plate 1. The pressurization range of the top airbag 7 covers at least 4 / 5 of the upper surface area of ​​the sand layer, ensuring uniform pressure on the sand layer inside the test chamber below. The top airbag inflation tube 5 is fixedly installed on the top plate 1. After the top plate 1 is installed with the test chamber, the pressurization airbag 7 is also installed at the same time. The external air source can be directly connected through the top airbag inflation tube 5 on the top plate 1 to pressurize the sand layer inside the test chamber. The side airbags 8 are located between the left and right side plates 2 and the simulated sand layer 16. The side airbags 8 are attached to the inner side of the left and right side plates 2 and are slightly smaller than the area of ​​the side plates. The pressurization range of the side airbags 8 covers at least 4 / 5 of the side area of ​​the sand layer, ensuring uniform pressure on the sand layer inside the side test chamber. The side airbag inflation tube 10 is fixed on the left and right side plates 2. After the left and right side plates 2 are installed with the test chamber, the pressure airbag 8 is also installed at the same time. The external air source can be directly connected through the side airbag inflation tube 10 on the top plate 1 to pressurize the sand layer inside the test chamber.

[0021] Both the top airbag inflation tube 5 and the side airbag inflation tube 10 are equipped with pressure sensors 21 to detect the internal air pressure of the top airbag 7 and the side airbag 8. During the inflation and deflation of the top airbag 7 and the side airbag 8, the pressure sensors 21 detect the internal pressure of the top airbag 7 and the side airbag 8, and the pressure applied by the airbags to the sand layer is controlled by feedback to adjust the pressure environment of the sand layer at different underground depths for the test.

[0022] The water supply assembly includes an inlet 9 and an outlet 15, both equipped with flow meters and check valves. The inlet 9 is connected to an external water supply system, allowing water to be added to the sand layer inside the test chamber to simulate a water-rich sand layer environment. Excess water is discharged through the outlet 15 on the base 3. Flow meters and check valves are installed on both the inlet 9 and outlet 15 to control the opening and closing of the water supply assembly. The flow meters also measure the flow rate of the leachate. The water supply assembly injects water into the simulated sand layer 16 inside the test chamber to simulate water-rich environments at different burial depths, thereby adjusting sand layer tests with different moisture contents. Furthermore, the change in porosity of the sand layer before and after grouting can be obtained by observing the degree of filtrate precipitation, thus revealing the spatiotemporal evolution law of the internal pores of the sand layer.

[0023] The grouting assembly includes a grouting pipe 6, which has openings on both sides of the pipe body. The monitoring assembly includes a pore water pressure gauge 20, a pressure sensor 21, and a displacement sensor 19. The pressure sensor 21 and the pore water pressure gauge 20 are arranged at different layers of the sand layer, with equal intervals between layers starting 50mm from the center of the grouting pipe 6, moving forward and backward, left and right. The pressure sensor 21 can monitor the pressure attenuation of the grout diffusion between sand layers before and after grouting, and can also monitor the consolidation force during the grout setting process. The pore water pressure gauge 20 can detect the change in pore pressure within the sand layer before and after grouting, and can also detect the grout diffusion resistance before and after grouting. The pressure sensor 21, displacement sensor 19, pore water pressure gauge 20, and the flow meter of the water supply assembly are connected to a wireless signal receiving device; the signal is fed back to the data analysis device via a signal collection device, and the corresponding detection data is output by the data analysis software inside the data analysis device. Regarding the sensors in the detection system of this embodiment, all are existing mature detection technologies; the specific detection principles and data processing methods are not described in detail here.

[0024] like Figure 5 As shown, a method for simulating the diffusion of infiltration grouting in deeply buried loose water-bearing sand layers includes the following steps: Step S1: Assemble the test chamber and prepare the sand layer.

[0025] Assemble the test chamber by connecting and fixing the top plate 1, left and right side plates 2, base 3, and front and rear baffles 4 with stainless steel frames and bolts to form a detachable test chamber. Install the middle partition 14 and tenon structure 12 (including partition limiter 11), and use the sliding middle partition 14 to divide the internal space of the test chamber into multiple target areas. Prepare a simulated sand layer 16 by filling sand into the test chamber from the top to form a simulated sand layer 16. Ensure that the sand layer is filled evenly according to the test requirements to lay the foundation for subsequent tests.

[0026] Step S2: Simulate the stress environment of sand layer 16; Install the airbag assembly, attaching the top airbag 7 below the top plate 1 and the side airbags 8 to the inner sides of the left and right side plates 2. Connect the airbags to an external air source through the top airbag inflation pipe and the side airbag inflation pipe 10. Apply confining pressure. Based on the underground burial depth of the simulated sand layer 16, inflate the top airbag 7 and the side airbags 8 to compress the simulated sand layer 16 (the top airbag covers ≥4 / 5 of the upper surface area of ​​the sand layer, and the side airbags 8 cover ≥4 / 5 of the side area of ​​the sand layer to ensure uniform pressure), simulating the underground stress environment at different burial depths.

[0027] Step S3: Simulate a water-rich environment.

[0028] The water supply system is activated, injecting water into the simulated sand layer 16 through injection port 9. Excess water is discharged from outlet 15. The injection volume is controlled by flow meters and check valves at injection ports 9 and 15 to adjust the moisture content of the sand layer and simulate water-rich conditions at different burial depths. Initial parameters are monitored by monitoring the initial pore water pressure of the sand layer using pore water pressure gauge 20 and recording the initial injection volume using flow meters, providing baseline data for subsequent comparisons.

[0029] Step S4: Perform grouting operation; Install the grouting assembly, ensuring that the grouting pipe 6 is fixed in the middle of the top airbag 7 and aligned with the target area of ​​the simulated sand layer 16. Perform grouting by injecting grout into the simulated sand layer 16 through the grouting pipe 6. The grout is evenly diffused through the opening structure of the grouting pipe 6. At the same time, start recording basic parameters such as grouting time and grouting volume.

[0030] Step S5: Real-time monitoring and data acquisition; The monitoring components are activated, and data is collected in real time via pressure sensors 21, pore water pressure gauges 20, displacement sensors 19, and flow meters of the water supply components, which are deployed at different levels in the simulated sand layer 16. Data transmission occurs through a wireless signal receiving device to a signal collection device, which then feeds it back to the data analysis device.

[0031] Step S6: Data processing and result analysis; Data analysis involves processing collected data such as pressure, displacement, pore water pressure, and flow rate using software within the data analysis device, and outputting the detection results. Pattern summarization involves analyzing the diffusion patterns of the grout, the spatiotemporal evolution of sand layer porosity, and the consolidation characteristics of the grout based on the data results, leading to relevant conclusions regarding the diffusion of infiltration grout in deeply buried loose, water-bearing sand layers.

[0032] This invention employs the aforementioned simulation test device and method for permeation grouting diffusion in deeply buried loose water-bearing sand layers. The test platform is easy to assemble and the operation process is simple. It is of great significance for improving the grouting modification effect of water-rich sand layers in the field and is conducive to the promotion and application of grouting modification of target sand layers in engineering practice.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A device for simulating the penetration and diffusion of grouting in deep-buried loose water-containing sand layers, characterized in that, The utility model relates to a kind of stress and water environment simulation test device, including modular test platform, water supply assembly, grouting assembly and monitoring assembly, and the modular test platform includes test box and air bag assembly;Two sides and bottom of test box are equipped with water inlet and water outlet in water supply assembly, middle part of top air bag in air bag assembly is equipped with grouting pipe in grouting assembly, displacement sensor is arranged inside top plate and left and right side plate of test box.

2. The permeation grouting diffusion simulation test device for deep buried loose water-containing sand layer according to claim 1, characterized in that, Test box includes top plate, left and right side plate, base and front and rear baffle, and the outside of test box is equipped with stainless steel frame connection and fixation, and front and rear baffle and left and right side plate are spliced by organic glass plate, and organic glass plate and stainless steel frame are fixedly connected by side bolt;Test box is filled with simulated sand layer, middle partition and mortise and tenon structure, and partition stopper is arranged on mortise and tenon structure, and top plate is fixedly connected with base by bolt connecting rod, and fixed bolt is arranged in the center of the bottom plate of test box.

3. The permeation grouting diffusion simulation test device for deep buried loose water-containing sand layer according to claim 1, characterized in that, Air bag includes top air bag, top air bag inflation pipe, side air bag and side air bag inflation pipe, and top air bag is attached to the lower side of top plate, and top air bag inflation pipe is fixedly arranged on top plate, and side air bag is located between left and right side plate and simulated sand layer, and side air bag is attached to the inside of left and right side plate, and side air bag inflation pipe is fixedly arranged on left and right side plate, and pressure sensor is arranged on top air bag inflation pipe and side air bag inflation pipe.

4. The permeation grouting diffusion simulation test device for deep buried loose water-containing sand layer according to claim 1, characterized in that, Water supply assembly includes water inlet and water outlet, and flowmeter and one-way valve are arranged on water inlet and water outlet.

5. The permeation grouting diffusion simulation test device for deep buried loose water-containing sand layer according to claim 1, characterized in that, Grouting assembly includes grouting pipe, and grouting pipe is provided with holes on both sides of pipe body.

6. The permeation grouting diffusion simulation test device for deep buried loose water-containing sand layer according to claim 1, characterized in that, Monitoring assembly includes pore water pressure gauge, pressure sensor and displacement sensor, and pressure sensor, displacement sensor and pore water pressure gauge and flowmeter of water supply assembly are connected with wireless signal receiving device respectively.

7. The method for simulating the permeation and grouting diffusion of a deeply buried loose water-containing sand layer according to any one of claims 1-6, characterized in that, It includes the following steps: Step S1, assemble test box and prepare sand layer; Assemble test box, and top plate, left and right side plate, base, front and rear baffle are fixedly connected by stainless steel frame and bolt, to form detachable test box;Install middle partition and mortise and tenon structure, and the internal space of test box is divided into multiple target areas by sliding middle partition; Prepare simulated sand layer, fill sand from top to test box, to form simulated sand layer; Step S2, stress environment of simulated sand layer; Install air bag assembly, and top air bag is attached to the lower side of top plate, and side air bag is attached to the inside of left and right side plate, and external gas source is connected through top air bag inflation pipe and side air bag inflation pipe;Apply confining pressure, and according to the underground burial depth of simulated sand layer, inflate top air bag and side air bag, to extrude simulated sand layer, to simulate underground stress environment of different burial depth; Step S3, simulate water-rich environment; Start water supply assembly, and inject water into simulated sand layer through water inlet, and excess water is discharged from water outlet;Simulate water-rich conditions of different burial depth through flowmeter and one-way valve of water inlet and water outlet;Initial parameter monitoring, monitor initial pore water pressure of sand layer through pore water pressure gauge, and record initial water injection amount through flowmeter, Step S4, grouting operation is carried out; Install the grouting assembly, make sure the grouting pipe is fixed through the middle of the top air bag and aligns with the target area of the simulated sand layer; implement grouting, inject slurry into the simulated sand layer through the grouting pipe, make the slurry evenly spread through the opening structure of the grouting pipe, and start recording basic parameters such as grouting time and grouting amount. Step S5, real-time monitoring and data acquisition; Start the monitoring assembly, and acquire data in real time through the pressure sensor, the pore water pressure gauge, the displacement sensor arranged at different layers of the simulated sand layer, and the flow meter of the water supply assembly; Data transmission, the data of each sensor and flow meter is transmitted to the signal collection device through the wireless signal receiving device, and then fed back to the data analysis device; Step S6, data processing and result analysis; Data analysis, process the collected data of pressure, displacement, pore water pressure, and flow rate through the software in the data analysis device, and output the detection result; rule summary, analyze the diffusion law of the grouting slurry, the time-space evolution of the sand layer porosity, and the slurry consolidation characteristics according to the data result, and obtain the related conclusions of the penetration grouting diffusion of the deep-buried loose water-containing sand layer.

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