Weak interaction stratum grouting reinforcement test device and test method

Abstract

The invention discloses a weak interaction stratum grouting reinforcement test device and a test method. The device comprises a weak interaction stratum structural body, a stress loading mechanism, a grouting mechanism, a slurry diffusion monitoring mechanism, a rock mass deformation monitoring mechanism and a data acquisition mechanism. The soft interaction stratum structural body is located in a pressurization pressure chamber of the stress loading mechanism, and the grout outlet end of the grouting mechanism is in fluid communication with the grout inlet end of the position to be reinforced of the soft interaction stratum structural body. The signal collection end of the slurry diffusion monitoring mechanism is located in the soft interaction stratum structure body, and the signal output end of the slurry diffusion monitoring mechanism is in signal connection with the slurry diffusion signal input end of the data acquisition mechanism; the signal collecting end of the rock mass deformation monitoring mechanism is located in the soft interaction stratum structure body, and the signal output end of the rock mass deformation monitoring mechanism is in signal connection with the rock mass deformation signal input end of the data collecting mechanism. According to the method, related analysis methods and technical supports can be provided for grouting reinforcement analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of soft interactive formation reinforcement. Specifically, it is a grouting reinforcement test device and test method for soft interactive formations. Background Art

[0002] In tunnel construction, the phenomenon of alternating fractured basalt and tuff often occurs. To ensure the smooth progress of the project, grouting is usually used for treatment. However, on-site practical experience shows that fissure grouting can achieve good reinforcement effects on fractured basalt formations, but the grouting effect on tuff formations is not obvious. Therefore, evaluating the grouting effect and diffusion analysis for such soft interactive formations with different properties is a difficult problem to solve. The advanced pre-grouting technology is a technology that uses ground "L"-shaped directional drilling for grouting. It can reinforce the driving roadway in advance without disturbing underground construction. However, since it is difficult to determine the grouting diffusion law of such soft interactive formations through current tests and theoretical analyses, there are deficiencies in the evaluation of the grouting effect for such soft interactive formations, and targeted measures cannot be taken to improve the corresponding technology. It is urgent to explore the grouting diffusion mechanism in such soft interactive formations to provide parameter basis for the improvement of the advanced drilling grouting technology.

[0003] Patent CN115791896A discloses a test device and method for grouting diffusion analysis of high-temperature formations based on resistivity detection, which is mainly used to simulate the grouting process of soil media. Patent number CN118130319A discloses a simulation in-situ formation grouting diffusion analysis experimental device and its use method, which is mainly for simulating the grouting diffusion analysis of soil layers under environmental pressure. Patent CN117368051A discloses a test device for grouting diffusion mechanism of water-rich fractured rock mass in deep formations, which can simulate the grouting process of water-rich fractured rock mass in deep formations. Patent CN116359077A discloses a simulation test system and method for grouting migration and diffusion in deep formations in a hot-rich area, which is mainly based on the analysis of fissured rock samples for grouting migration and diffusion. Patent CN107389898A discloses a visualization simulation test device and method for grouting diffusion law of dynamic water and sand formation reinforcement, which is aimed at the grouting water blocking simulation of double chemical slurries in water and sand formations. CN109667589A discloses a full-section visualization simulation test device and method for synchronous grouting of shield tunneling in ultra-deep formations, which is used to simulate the synchronous grouting process of shield construction in soil.

[0004] The above patents mainly focus on the grouting analysis of a single formation, and it is difficult to analyze the differences in grouting of soft interbedded formations, especially in terms of grouting diffusion at the junction of soft formations and the stability of the excavated chamber after reinforcement. It is difficult for existing experimental devices to obtain relevant laws. Summary of the Invention

[0005] To this end, the technical problem to be solved by the present invention is to provide a grouting reinforcement test device and test method for soft interbedded strata, which can truly simulate the difference in the diffusion of grout in soft interbedded strata during the grouting process, and carry out relevant tests on the diffusion law and grouting effect evaluation of different grouting pressures, different grouting depths, and different grouts in different soft interbedded strata. The grouting reinforcement test device and test method of the present invention can provide relevant analysis methods, parameter bases, and technical supports for the on-site implementation of the grouting reinforcement process for soft interbedded strata.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] A grouting reinforcement test device for soft interbedded strata, comprising a soft interbedded stratum structure body, a stress loading mechanism, a grouting mechanism, a slurry diffusion monitoring mechanism, a rock mass deformation monitoring mechanism, and a data acquisition mechanism; the soft interbedded stratum structure body is located in the pressure chamber of the stress loading mechanism; the slurry outlet end of the grouting mechanism is in fluid communication with the slurry inlet end of the position to be reinforced of the soft interbedded stratum structure body; the signal collection end of the slurry diffusion monitoring mechanism is located inside the soft interbedded stratum structure body, and the signal output end of the slurry diffusion monitoring mechanism is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism; the signal collection end of the rock mass deformation monitoring mechanism is located inside the soft interbedded stratum structure body, and the signal output end of the rock mass deformation monitoring mechanism is signal-connected to the rock mass deformation signal input end of the data acquisition mechanism.

[0008] In the above grouting reinforcement test device for soft interbedded strata, the stress loading mechanism includes a hydraulic pump and a hydraulic control system (which can adjust different loading pressures and displacements), and the hydraulic control system controls the hydraulic pump to apply three-way forces to the soft interbedded stratum structure body to simulate the formation stress, or it can also be other stress loading mechanisms that can apply three-way forces to the soft interbedded stratum structure body; the data acquisition mechanism is a multi-parameter integrated data acquisition system, including interfaces for different sensors, isolation amplifiers, filters, and multi-channel sampling configurations, or it can also be other data acquisition mechanisms that can collect the data information monitored by the slurry diffusion monitoring mechanism and the rock mass deformation monitoring mechanism.

[0009] The above-mentioned grouting reinforcement test device for soft interbedded strata, wherein the grouting mechanism comprises a grouting pump, a slurry agitator, a constant temperature water tank, a grouting hose and a flow monitor; the slurry agitator is arranged in the constant temperature water tank, the fluid outlet end of the constant temperature water tank is in fluid communication with the fluid inlet end of the flow monitor, the fluid outlet end of the flow monitor is in fluid communication with the fluid inlet end of the grouting pump, the fluid outlet end of the grouting pump is in fluid communication with the fluid inlet end of the grouting hose, and the fluid outlet end of the grouting hose is in fluid communication with the slurry inlet end of the position to be reinforced of the soft interbedded strata structure; the flow monitor is a control valve.

[0010] The above-mentioned grouting reinforcement test device for soft interbedded strata, wherein the slurry diffusion monitoring mechanism comprises a fiber Bragg grating temperature sensor and a apparent resistivity electrode; the temperature measurement probe of the fiber Bragg grating temperature sensor is arranged inside the soft interbedded strata structure, and the temperature signal output end of the fiber Bragg grating temperature sensor is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism; the apparent resistivity electrode is arranged inside the soft interbedded strata structure, and the apparent resistivity signal output end of the apparent resistivity electrode is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism; according to the size of the soft interbedded strata structure, the fiber Bragg grating temperature sensor is arranged in at least 3 layers (at least 1 layer is arranged in each of the fractured basalt layer, the soft interbedded layer and the tuff layer) in a layered arrangement inside the soft interbedded strata structure, and at least 9 are evenly arranged in each layer; the apparent resistivity electrode is arranged in at least 3 layers (at least 1 layer is arranged in each of the fractured basalt layer, the soft interbedded layer and the tuff layer) in a layered arrangement inside the soft interbedded strata structure, and at least 3 are arranged in parallel in each layer.

[0011] The above-mentioned grouting reinforcement test device for soft interbedded strata, wherein the rock mass deformation monitoring mechanism comprises a stress-strain sensor, the signal collection end of the stress-strain sensor is located inside the soft interbedded strata structure, and the signal output end of the stress-strain sensor is signal-connected to the rock mass deformation signal input end of the data acquisition mechanism; according to the size of the soft interbedded strata structure, the stress-strain sensor is arranged in at least 3 layers (at least 1 layer is arranged in each of the fractured basalt layer, the soft interbedded layer and the tuff layer) in a layered arrangement inside the soft interbedded strata structure, and at least 9 are evenly arranged in each layer.

[0012] The above-mentioned grouting reinforcement test device for soft interbedded strata, wherein the soft interbedded strata structure body is a soft interbedded strata structure printed by a 3D printer, and prefabricated fissures are arranged inside the soft interbedded strata structure, and the slurry diffusion monitoring mechanism and the rock mass deformation monitoring mechanism are arranged; or, the soft interbedded strata structure body is a layered compaction of cataclastic rock and tuff sampled on site, and corresponding reserved sleeves are buried at the same time (the reserved sleeves are used to connect the grouting pipelines of the grouting mechanism to ensure that the slurry diffuses out from the bottom of the hole; the reserved sleeves are generally arranged at the center of the soft interbedded strata structure body), and the slurry diffusion monitoring mechanism and the rock mass deformation monitoring mechanism are arranged.

[0013] A grouting reinforcement test method for soft interbedded strata includes the following steps:

[0014] Step (1), prepare a soft interbedded strata structure body, and during the preparation of the soft interbedded strata structure body, arrange a slurry diffusion monitoring mechanism and a rock mass deformation monitoring mechanism inside the soft interbedded strata structure body, and the signal collection end of the slurry diffusion monitoring mechanism is located inside the soft interbedded strata structure body, and the signal output end of the slurry diffusion monitoring mechanism is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism; the signal collection end of the rock mass deformation monitoring mechanism is located inside the soft interbedded strata structure body, and the signal output end of the rock mass deformation monitoring mechanism is signal-connected to the rock mass deformation signal input end of the data acquisition mechanism;

[0015] Step (2), place the soft interbedded strata structure body in the pressure chamber of the stress loading mechanism, and fluidly connect the slurry outlet end of the grouting mechanism to the slurry inlet end of the position to be reinforced of the soft interbedded strata structure body;

[0016] Step (3), start the grouting mechanism to grout the soft interbedded strata structure body, and at the same time apply triaxial stress to the soft interbedded strata structure body during the grouting process through the stress loading mechanism to simulate the formation pressure; during the grouting process, the data acquisition mechanism synchronously collects the data transmitted by the slurry diffusion monitoring mechanism; different grouting tests are carried out by setting different grouting pressures and grouting volumes (different grouting conditions can be set for the soft interbedded strata structure bodies prepared from different rock samples, and different grouting pressures, grouting volumes and grouting can also be set from different positions for the soft interbedded strata structure bodies prepared from the same rock sample);

[0017] Step (4), after the grouting is completed and waiting for 3 days for the slurry to solidify, drill and core the grouted and reinforced soft interbedded strata structure body; and collect the rock mass deformation data information of the soft interbedded strata structure body after coring through the rock mass deformation monitoring mechanism, so as to obtain the real stability characteristics of the grouted and reinforced formation;

[0018] Step (5): Disassemble the soft interbedded formation structure after grouting reinforcement, and repeat steps (1) to (4) to obtain the laws of grout diffusion and reinforcement effects for different grouting depths, different grouting fluids, and different soft interbedded formations.

[0019] In the above-mentioned soft interbedded formation grouting reinforcement test method, in step (1), the soft interbedded formation structure is a soft interbedded formation structure printed by a 3D printer, and prefabricated cracks are arranged inside the soft interbedded formation structure, and the grout diffusion monitoring mechanism and the rock mass deformation monitoring mechanism are arranged; or, the soft interbedded formation structure is the cataclastic rock and tuff sampled on-site and directly placed in the pressure chamber of the stress loading mechanism for layered compaction, and the corresponding reserved casing is buried while arranging the grout diffusion monitoring mechanism and the rock mass deformation monitoring mechanism, and the reserved casing is pulled out during grouting.

[0020] In the above-mentioned soft interbedded formation grouting reinforcement test method, the stress loading mechanism includes a hydraulic pump and a hydraulic control system (which can adjust different loading pressures and displacements), and the hydraulic control system controls the hydraulic pump to apply triaxial stress to the soft interbedded formation structure to simulate formation stress, or it can also be other stress loading mechanisms that can apply triaxial stress to the soft interbedded formation structure; the data acquisition mechanism is a multi-parameter integrated data acquisition system, including interfaces for different sensors, isolation amplifiers, filters, and multi-channel sampling configurations, or it can also be other data acquisition mechanisms that can collect the data information monitored by the grout diffusion monitoring mechanism and the rock mass deformation monitoring mechanism; the grouting mechanism includes a grouting pump, a grout agitator, a constant temperature water tank, a grouting hose, and a flow monitor; the grout agitator is arranged in the constant temperature water tank, the fluid outlet end of the constant temperature water tank is fluidly connected to the fluid inlet end of the flow monitor, the fluid outlet end of the flow monitor is fluidly connected to the fluid inlet end of the grouting pump, the fluid outlet end of the grouting pump is fluidly connected to the fluid inlet end of the grouting hose, and the fluid outlet end of the grouting hose is fluidly connected to the grout inlet end of the soft interbedded formation structure at the position to be reinforced.

[0021] The above-mentioned grouting reinforcement test method for soft interbedded strata, wherein the slurry diffusion monitoring mechanism includes fiber Bragg grating temperature sensors and apparent resistivity electrodes; the temperature measurement probes of the fiber Bragg grating temperature sensors are arranged inside the soft interbedded stratum structure, and the temperature signal output ends of the fiber Bragg grating temperature sensors are signal-connected to the slurry diffusion signal input ends of the data acquisition mechanism; the apparent resistivity electrodes are arranged inside the soft interbedded stratum structure, and the apparent resistivity signal output ends of the apparent resistivity electrodes are signal-connected to the slurry diffusion signal input ends of the data acquisition mechanism; according to the size of the soft interbedded stratum structure, the fiber Bragg grating temperature sensors are arranged in at least 3 layers in a layered manner inside the soft interbedded stratum structure (at least 1 layer is arranged in each of the fractured basalt layer, the soft interbedded layer and the tuff layer), and at least 9 are evenly arranged in each layer; the apparent resistivity electrodes are arranged in at least 3 layers in a layered manner inside the soft interbedded stratum structure (at least 1 layer is arranged in each of the fractured basalt layer, the soft interbedded layer and the tuff layer), and at least 3 are arranged in parallel in each layer;

[0022] The rock mass deformation monitoring mechanism includes stress-strain sensors, the signal collection ends of the stress-strain sensors are located inside the soft interbedded stratum structure, and the signal output ends of the stress-strain sensors are signal-connected to the rock mass deformation signal input ends of the data acquisition mechanism; according to the size of the soft interbedded stratum structure, the stress-strain sensors are arranged in at least 3 layers in a layered manner inside the soft interbedded stratum structure (at least 1 layer is arranged in each of the fractured basalt layer, the soft interbedded layer and the tuff layer), and at least 9 are evenly arranged in each layer.

[0023] The technical solution of the present invention has achieved the following beneficial technical effects:

[0024] 1. The grouting reinforcement test device and method for soft interbedded strata of the present invention are used indoors to simulate the grouting reinforcement process of soft interbedded strata, analyze the diffusion law of different strata under different grouting pressures, and at the same time drill holes and take cores in the grouting area to evaluate its grouting effect, providing relevant test devices and methods for the design and optimization of grouting technology.

[0025] 2. The simulation test platform for the grouting reinforcement test of soft interbedded strata provided by the present invention can be used for the research on the grouting diffusion mechanism of soft interbedded strata. Sensors are arranged in advance for the layered reinforcement of the soft interbedded strata on this test platform, or a 3D-printed soft stratum can be directly placed in it, corresponding stratum stress is applied, the casing is pulled out before grouting, and grouting analysis is carried out. The present invention can solve the problem of lack of analysis of the grouting diffusion mechanism of soft interbedded strata, especially the lack of research on the grouting diffusion law of rock strata with large differences in injectability. At the same time, after reinforcement, drill holes and take cores to obtain its deformation and failure characteristics under stress, so as to simulate the influence law on the grouted solid after excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the grouting drilling depth of the soft interbedded stratum structure body in the embodiment of the present invention (drilling to the fractured basalt layer);

[0027] Figure 2 Schematic diagram of the grouting drilling depth of the soft interbedded stratum structure body in the embodiment of the present invention (drilling to the soft interbedded layer);

[0028] Figure 3 Schematic diagram of the grouting drilling depth of the soft interbedded stratum structure body in the embodiment of the present invention (drilling to the tuff layer);

[0029] Figure 4 Schematic diagram of the three-way stress of the soft interbedded stratum structure body in the embodiment of the present invention;

[0030] Figure 5 Schematic diagram of the grouting reinforcement test device for the soft interbedded stratum in the embodiment of the present invention.

[0031] The reference numerals in the figure are represented as: 1 - soft interbedded stratum structure body; 2 - stress loading mechanism; 3 - data acquisition mechanism; 4 - fiber Bragg grating temperature sensor; 5 - stress and strain sensor; 6 - apparent resistivity electrode; 7 - grouting hose; 8 - grouting pump; 9 - flow monitor; 10 - constant temperature water tank; 11 - slurry agitator; 101 - fractured basalt layer; 102 - soft interbedded layer; 103 - tuff layer; 104 - grouting drilling and coring depth; 201 - hydraulic control system; 202 - reserved opening. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] As Figure 5 shown, the grouting reinforcement test device for the soft interbedded stratum in this embodiment includes a soft interbedded stratum structure body 1, a stress loading mechanism 2, a grouting mechanism, a slurry diffusion monitoring mechanism, a rock mass deformation monitoring mechanism, and a data acquisition mechanism 3;

[0033] The stress loading mechanism 2 includes a hydraulic pump and a hydraulic control system 201. It mainly uses its pressure cylinder and hydraulic control system 201 to apply triaxial stress to the soft interbedded formation structure 1, aiming to simulate the characteristics of real in-situ stress and the characteristics of rock formations under high-pressure grouting. In this embodiment, the stress loading mechanism 2 can adjust different loading pressures and displacements, and the hydraulic control system 201 controls the hydraulic pump to apply triaxial forces to the soft interbedded formation structure 1 to simulate formation stress. In some other embodiments, it can also be other stress loading mechanisms that can achieve applying triaxial forces to the soft interbedded formation structure 1. The data acquisition mechanism 3 is a multi-parameter comprehensive data acquisition system, including interfaces for different sensors, isolation amplifiers, filters, and multi-channel sampling configurations. In some other embodiments, it can also be other data acquisition mechanisms that can collect the data information monitored by the liquid diffusion monitoring mechanism and the rock mass deformation monitoring mechanism.

[0034] The soft interbedded formation structure 1 is located in the pressurized pressure chamber of the stress loading mechanism 2.

[0035] The grouting mechanism includes a grouting pump 8 (high-pressure pump), a slurry agitator 11, a constant-temperature water tank 10, a grouting hose 7, and a flow monitor 9 (in this embodiment, the flow monitor is a control valve). The slurry agitator 11 is arranged in the constant-temperature water tank 10. The fluid outlet end of the constant-temperature water tank 10 is fluidly connected to the fluid inlet end of the flow monitor 9. The fluid outlet end of the flow monitor 9 is fluidly connected to the fluid inlet end of the grouting pump 8. The fluid outlet end of the grouting pump 8 is fluidly connected to the fluid inlet end of the grouting hose 7. The fluid outlet end of the grouting hose 7 is fluidly connected to the slurry inlet end of the soft interbedded formation structure 1 at the position to be reinforced. The grouting mechanism can achieve the adjustment of the injection pressure and the control of the grouting volume during grouting, and keep the injected slurry at a constant temperature, which is convenient for monitoring the grouting diffusion distance.

[0036] The slurry diffusion monitoring mechanism includes a fiber Bragg grating temperature sensor 4 and a apparent resistivity electrode 6; the temperature measurement probe of the fiber Bragg grating temperature sensor 4 is arranged inside the weak interaction stratum structure 1, and the temperature signal output end of the fiber Bragg grating temperature sensor 4 is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism 3; the apparent resistivity electrode 6 is arranged inside the weak interaction stratum structure 1, and the apparent resistivity signal output end of the apparent resistivity electrode 6 is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism 3; the fiber Bragg grating temperature sensor 4 is arranged in 3 layers (1 layer for each of the fractured basalt layer 101, the weak interaction layer 102, and the tuff layer 103) in a layered arrangement inside the weak interaction stratum structure 1, and 9 are evenly arranged in each layer; the apparent resistivity electrode 6 is arranged in 3 layers (1 layer for each of the fractured basalt layer 101, the weak interaction layer 102, and the tuff layer 103) in a layered arrangement inside the weak interaction stratum structure 1, and 3 are arranged in parallel in each layer.

[0037] By injecting slurry at a constant temperature, the fiber Bragg grating temperature sensor 4 can accurately sense the positions of different slurry diffusions; the arranged apparent resistivity electrode 6 can obtain the apparent resistivity signals of the weak interaction stratum structure 1 before and after grouting. Through the data transmitted by the fiber Bragg grating temperature sensor 4 and the apparent resistivity electrode 6, the real-time grouting diffusion range can be obtained, and then the image of apparent resistivity - diffusion position - time under different conditions can be analyzed, so as to obtain the influence law of grouting pressure and grouting depth on the grouting diffusion range in the weak interaction stratum structure 1.

[0038] The rock mass deformation monitoring mechanism includes a stress-strain sensor 5, the signal collection end of the stress-strain sensor 5 is located inside the weak interaction stratum structure 1, and the signal output end of the stress-strain sensor 5 is signal-connected to the rock mass deformation signal input end of the data acquisition mechanism 3; it is arranged in 3 layers (1 layer for each of the fractured basalt layer 101, the weak interaction layer 102, and the tuff layer 103) in a layered arrangement inside the weak interaction stratum structure 1, and 9 are evenly arranged in each layer; after the grouting reinforcement is completed, the core drilling is used to simulate the excavation process. During and after the core drilling process, by collecting the data transmitted by the stress-strain sensor 5 near the core drilling position, the rock mass deformation characteristics during the core drilling simulation excavation process can be obtained.

[0039] In this embodiment, the weak interaction formation structure body 1 is a weak interaction formation structure printed by a 3D printer, and prefabricated fissures are arranged inside the weak interaction formation structure, and the slurry diffusion monitoring mechanism and the rock mass deformation monitoring mechanism are arranged; in some other embodiments, the weak interaction formation structure body 1 can also be formed by layering and compacting the fractured rock and tuff sampled on site, and corresponding reserved sleeves are buried while arranging the slurry diffusion monitoring mechanism and the rock mass deformation monitoring mechanism.

[0040] The grouting reinforcement test method for the weak interaction formation in this embodiment includes the following steps:

[0041] Step (1): A weak interaction formation structure printed by a 3D printer, and prefabricated fissures are arranged inside the weak interaction formation structure body 1, and the slurry diffusion monitoring mechanism and the rock mass deformation monitoring mechanism are arranged, so that the signal collection end of the slurry diffusion monitoring mechanism is located inside the weak interaction formation structure body 1, and the signal output end of the slurry diffusion monitoring mechanism is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism 3; the signal collection end of the rock mass deformation monitoring mechanism is located inside the weak interaction formation structure body 1, and the signal output end of the rock mass deformation monitoring mechanism is signal-connected to the rock mass deformation signal input end of the data acquisition mechanism 3;

[0042] Step (2): Place the weak interaction formation structure body 1 in the pressure chamber of the stress loading mechanism 2, and fluidly connect the slurry outlet end of the grouting mechanism to the slurry inlet end of the position to be reinforced of the weak interaction formation structure body 1; Connect the sensors of the slurry diffusion monitoring mechanism and the rock mass deformation monitoring mechanism to the data acquisition mechanism 3 and conduct debugging, and prepare the corresponding grouting liquid;

[0043] Step (3): After the slurry in the constant temperature water tank 10 reaches the set temperature and is constant, start the grouting mechanism to grout the weak interaction formation structure body 1, and at the same time apply triaxial stress to the weak interaction formation structure body 1 during the grouting process through the stress loading mechanism 2 (see Figure 4 ) to simulate the formation pressure; during the grouting process, the data acquisition mechanism 3 synchronously collects the data transmitted by the slurry diffusion monitoring mechanism; Different grouting tests are carried out by setting different grouting pressures and grouting volumes;

[0044] Step (4), after the grout is injected and allowed to solidify for 3 days, core drilling is carried out on the soft interbedded stratum structure 1 after grouting reinforcement; at the reserved opening 202 (a glass opening is reserved on the glass cover of the pressure chamber of the stress loading mechanism 2 to facilitate grouting and core drilling), core drilling is carried out, and the rock mass deformation data information near the core in the soft interbedded stratum structure 1 after core drilling and core extraction is collected through the rock mass deformation monitoring mechanism, so as to obtain the stability characteristics of the grouted and reinforced stratum and the influence law of simulated excavation on the stress-strain characteristics of the rock mass; in this embodiment, the influence law of different grouting and core drilling depths on the grouting reinforcement effect of the soft interbedded stratum can be studied by adjusting the grouting and core drilling depth (see Figures 1 to 3 ).

[0045] Step (5), disassemble the soft interbedded stratum structure 1 after grouting reinforcement, and repeat steps (1) to (4) to obtain the laws of grouting diffusion and reinforcement effects for different grouting depths, different grouting fluids, and different soft interbedded strata.

[0046] Using the soft interbedded stratum grouting reinforcement test device and method of this embodiment, grouting diffusion analysis can be carried out in the strata of the soft interbedded stratum structure under different grouting pressures, different grouting depths, and different grouting fluids, solving the current lack of research on the grouting diffusion law of the soft interbedded stratum structure strata, and providing an important basis for the design of the grouting curtain for the soft interbedded stratum; at the same time, this test device can also obtain the laws related to the deformation and failure of the excavated rock mass after grouting reinforcement, providing an experimental basis for the corresponding support design.

[0047] Obviously, the above embodiments are only examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the claims of this patent application.

Claims

1. A grouting reinforcement test device for soft and weak alternating strata, characterized in that: The invention comprises a weak alternating stratum structure (1), a stress loading mechanism (2), a grouting mechanism, a slurry diffusion monitoring mechanism, a rock deformation monitoring mechanism and a data acquisition mechanism (3); the weak alternating stratum structure (1) is located in a pressurized pressure chamber of the stress loading mechanism (2); the slurry outlet end of the grouting mechanism is fluidly connected to the slurry inlet end of the position to be reinforced of the weak alternating stratum structure (1); the signal collection end of the slurry diffusion monitoring mechanism is located inside the weak alternating stratum structure (1), and the signal output end of the slurry diffusion monitoring mechanism is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism (3); the signal collection end of the rock deformation monitoring mechanism is located inside the weak alternating stratum structure (1), and the signal output end of the rock deformation monitoring mechanism is signal-connected to the rock deformation signal input end of the data acquisition mechanism (3).

2. The grouting reinforcement test device for soft alternating strata according to claim 1 is characterized in that: The stress loading mechanism (2) comprises a hydraulic pump and a hydraulic control system (201), wherein the hydraulic control system (201) controls the hydraulic pump to apply three-dimensional force to the soft alternating stratum structure (1) to simulate stratum stress; and the data acquisition mechanism (3) is a multi-parameter comprehensive data acquisition system.

3. The grouting reinforcement test device for soft alternating strata according to claim 1 is characterized in that: The grouting mechanism comprises a grouting pump (8), a slurry agitator (11), a constant temperature water tank (10), a grouting hose (7) and a flow monitor (9); the slurry agitator (11) is arranged in the constant temperature water tank (10), the fluid outlet end of the constant temperature water tank (10) is fluidly connected to the fluid inlet end of the flow monitor (9), the fluid outlet end of the flow monitor (9) is fluidly connected to the fluid inlet end of the grouting pump (8), the fluid outlet end of the grouting pump (8) is fluidly connected to the fluid inlet end of the grouting hose (7), and the fluid outlet end of the grouting hose (7) is fluidly connected to the slurry inlet end of the position to be reinforced of the weak alternating stratum structure (1).

4. The grouting reinforcement test device for soft alternating strata according to claim 1 is characterized in that: The slurry diffusion monitoring mechanism comprises a fiber Bragg grating temperature sensor (4) and an apparent resistivity electrode (6); the temperature measuring probe of the fiber Bragg grating temperature sensor (4) is arranged inside the soft and weak alternating stratum structure (1), and the temperature signal output end of the fiber Bragg grating temperature sensor (4) is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism (3); the apparent resistivity electrode (6) is arranged inside the soft and weak alternating stratum structure (1), and the apparent resistivity signal output end of the apparent resistivity electrode (6) is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism (3); the fiber Bragg grating temperature sensors (4) are arranged in at least three layers in a layered arrangement manner inside the soft and weak alternating stratum structure (1), and at least nine electrodes are evenly arranged in each layer; the apparent resistivity electrodes (6) are arranged in at least three layers in a layered arrangement manner inside the soft and weak alternating stratum structure (1), and at least three electrodes are arranged in parallel in each layer.

5. The grouting reinforcement test device for soft alternating strata according to claim 1 is characterized in that: The rock deformation monitoring mechanism comprises a stress and strain sensor (5); a signal collection end of the stress and strain sensor (5) is located inside the soft alternating stratum structure (1); a signal output end of the stress and strain sensor (5) is signal-connected to a rock deformation signal input end of the data acquisition mechanism (3); the stress and strain sensors (5) are arranged in at least three layers in a layered manner inside the soft alternating stratum structure (1), with at least nine sensors evenly arranged in each layer.

6. The grouting reinforcement test device for soft alternating strata according to claim 1 is characterized in that: The weak alternating stratum structure (1) is a weak alternating stratum structure printed by a 3D printer, and fissures are prefabricated inside the weak alternating stratum structure and the slurry diffusion monitoring mechanism and the rock deformation monitoring mechanism are arranged; or, the weak alternating stratum structure (1) is a layered compaction of shattered rock and tuff sampled on site, and corresponding reserved casings are buried and the slurry diffusion monitoring mechanism and the rock deformation monitoring mechanism are arranged.

7. A grouting reinforcement test method for soft alternating strata, characterized in that: The steps include: Step (1), preparing a weak alternating stratigraphic structure (1), and in the process of preparing the weak alternating stratigraphic structure (1), arranging a slurry diffusion monitoring mechanism and a rock deformation monitoring mechanism inside the weak alternating stratigraphic structure (1), and the signal collection end of the slurry diffusion monitoring mechanism is located inside the weak alternating stratigraphic structure (1), and the signal output end of the slurry diffusion monitoring mechanism is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism (3); the signal collection end of the rock deformation monitoring mechanism is located inside the weak alternating stratigraphic structure (1), and the signal output end of the rock deformation monitoring mechanism is signal-connected to the rock deformation signal input end of the data acquisition mechanism (3); Step (2), placing the soft alternating stratum structure (1) in a pressurized pressure chamber of a stress loading mechanism (2), and connecting the slurry outlet of a grouting mechanism to the slurry inlet of the position to be reinforced of the soft alternating stratum structure (1); Step (3), starting the grouting mechanism to perform grouting on the soft alternating stratum structure (1), and at the same time applying three-dimensional force to the soft alternating stratum structure (1) during the grouting process through the stress loading mechanism (2) to simulate the stratum pressure; during the grouting process, the data acquisition mechanism (3) synchronously acquires the data transmitted by the slurry diffusion monitoring mechanism; and performing different grouting tests by setting different grouting pressures and grouting volumes; Step (4), after the grouting is completed and the slurry solidifies, the soft alternating stratum structure (1) reinforced by grouting is drilled and cored; and the rock deformation data information of the soft alternating stratum structure (1) after coring is collected by the rock deformation monitoring mechanism; Step (5), dismantling the soft alternating stratum structure (1) after grouting reinforcement, repeating steps (1) to (4) to obtain the laws of grouting diffusion and reinforcement effects of different grouting depths, different grouting liquids and different soft alternating strata.

8. The grouting reinforcement test method for soft alternating strata according to claim 7 is characterized in that: In step (1), the weak alternating stratum structure (1) is a weak alternating stratum structure printed by a 3D printer, and cracks are prefabricated inside the weak alternating stratum structure and the slurry diffusion monitoring mechanism and the rock deformation monitoring mechanism are arranged; or, the weak alternating stratum structure (1) is a broken rock and tuff sampled on site, which are directly placed in the pressurized pressure chamber of the stress loading mechanism (2) for layered compaction, and the corresponding reserved casing is buried and the slurry diffusion monitoring mechanism and the rock deformation monitoring mechanism are arranged, and the reserved casing is pulled out during grouting.

9. The grouting reinforcement test method for soft alternating strata according to claim 7 is characterized in that: The stress loading mechanism (2) comprises a hydraulic pump and a hydraulic control system (201), wherein the hydraulic control system (201) controls the hydraulic pump to apply three-dimensional force to the soft alternating stratum structure (1) to simulate stratum stress; the data acquisition mechanism (3) is a multi-parameter comprehensive data acquisition system; the grouting mechanism comprises a grouting pump (8), a slurry agitator (11), a constant temperature water tank (10), a grouting hose (7) and a flow monitor (9); the slurry agitator (11) is arranged at the In the constant temperature water tank (10), the fluid outlet end of the constant temperature water tank (10) is fluidly connected to the fluid inlet end of the flow monitor (9), the fluid outlet end of the flow monitor (9) is fluidly connected to the fluid inlet end of the grouting pump (8), the fluid outlet end of the grouting pump (8) is fluidly connected to the fluid inlet end of the grouting hose (7), and the fluid outlet end of the grouting hose (7) is fluidly connected to the slurry inlet end of the position to be reinforced of the weak alternating stratum structure (1).

10. The grouting reinforcement test method for soft alternating strata according to claim 7, characterized in that: The slurry diffusion monitoring mechanism comprises a fiber Bragg grating temperature sensor (4) and an apparent resistivity electrode (6); the temperature measuring probe of the fiber Bragg grating temperature sensor (4) is arranged inside the soft and weak alternating stratum structure (1), and the temperature signal output end of the fiber Bragg grating temperature sensor (4) is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism (3); the apparent resistivity electrode (6) is arranged inside the soft and weak alternating stratum structure (1), and the apparent resistivity signal output end of the apparent resistivity electrode (6) is signal-connected to the slurry diffusion signal input end of the data acquisition mechanism (3); the fiber Bragg grating temperature sensors (4) are arranged in at least three layers in a layered manner inside the soft and weak alternating stratum structure (1), and at least nine are evenly arranged in each layer; the apparent resistivity electrodes (6) are arranged in at least three layers in a layered manner inside the soft and weak alternating stratum structure (1), and at least three are parallelly arranged in each layer; The rock deformation monitoring mechanism comprises a stress and strain sensor (5); a signal collection end of the stress and strain sensor (5) is located inside the soft alternating stratum structure (1); a signal output end of the stress and strain sensor (5) is signal-connected to a rock deformation signal input end of the data acquisition mechanism (3); the stress and strain sensors (5) are arranged in at least three layers in a layered manner inside the soft alternating stratum structure (1), with at least nine sensors evenly arranged in each layer.

Images