Weak rock mass sample preparation method and device and shear-seepage coupling test method

Abstract

The invention relates to a weak rock mass sample preparation method and device and a shear-seepage coupling test method, and the preparation method comprises the following steps: preparing a weak rock mass into a test sample through a sample preparation device, enabling the test sample to be suitable for a traditional shear-seepage testing machine, and performing a test by adopting the shear-seepage coupling test method. And mass and density data of fluid at a water inlet and a water outlet are collected in real time to complete real-time measurement of the mass loss of the weak rock mass in the shear-seepage coupling test process. Compared with the prior art, the method has the advantages that the application range is wide, the real state of the actual weak rock mass shear seepage process can be reflected more truly, and the like.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and in particular to a soft rock mass sealing device and a sample preparation and shear seepage coupling test method. Background Art

[0002] Large-scale hydropower projects or underground engineering construction often encounter geological conditions with weak rock interlayers, such as locally softened or muddied breccia, cataclasite, mylonite, etc. In addition, many major landslide disasters are also closely related to weak rock mass and weak rock mass structural surfaces, such as soft and hard interlayer landslides, weak interlayer landslides, etc. Under the interaction between weak rock mass and its structural surface and groundwater, its shear strength is significantly reduced, which may bring adverse effects to the project or cause geological disasters. Therefore, studying the shear-seepage characteristics of weak rock mass and its structural surface has important engineering significance and academic value.

[0003] At present, in the experimental research on water-rock degradation of weak rock mass, most of the research is on saturated softening, dry-wet cycle, etc., usually the strength indicators of non-coupled working conditions such as uniaxial compressive strength are measured to obtain the law, or the water-rock coupled triaxial test is carried out. At the same time, the current experimental equipment and methods for shear seepage coupling of rock structure are all carried out for hard rock. At present, there is a lack of research reports on direct shear-seepage coupling tests on weak rock mass and weak rock mass structural surfaces. The existing technology for sealing shear seepage tests is to press a silicone waterstop, rubber strip or other waterstop material at the shear joint of the specimen, and the pressure of the waterstop material needs to exceed the sealing water pressure to achieve stable sealing. When the water pressure is high, the pressure can be as high as several MPa. However, weak rock mass often cannot withstand this pressure due to its low strength, especially its strength will be further degraded during the test. On the other hand, the effect of this pressure on hard rock can be ignored, but it will cause large deformation on weak rock mass, which will have a non-negligible impact on the results. Therefore, in the prior art, it is impossible to stably seal the weak rock mass or the weak rock mass structural surface samples in the shear seepage coupling test, and thus the test cannot be carried out. In addition, most of the traditional shear seepage tests on hard rock are loaded by directly loading the samples into the shear box. However, the weak rock mass itself has a loose structure and low strength, and its structure further deteriorates or even cracks after encountering water. Therefore, in the prior art, directly loading the weak rock mass or the weak rock mass structural surface samples into the shear box may cause the weak rock mass to crack during the test, and thus the test cannot be carried out. Moreover, the shear seepage coupling process of the weak rock mass and its structural surface in nature is accompanied by material migration such as the dissolution of soluble minerals and the loss of fine solid particles. However, there is no method for quantitatively measuring the amount of material migration in the shear seepage coupling process of the weak rock mass and its structural surface.

[0004] In summary, the current experimental research on shear-seepage coupling of soft rock mass and its structural surface has the following problems:

[0005] 1. There is no test device specifically used for the shear-seepage coupling test of soft rock mass and its structural surface. Test devices suitable for hard rock are often used for testing. However, the hard rock test device will cause deformation of the soft rock mass.

[0006] Second, if the weak rock mass is placed directly in the test device, the sample will crack and the test cannot be carried out;

[0007] 3. In real life, the shear seepage coupling process of weak rock mass and its structural surface is accompanied by the dissolution of soluble minerals, the loss of fine solid particles and other material migration, which cannot be quantified by existing technology. Summary of the invention

[0008] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a method and device for preparing soft rock samples and a shear seepage coupling test method.

[0009] The present invention aims to solve the problem that the prior art cannot accurately and reliably carry out shear seepage coupling test research on soft rock mass and its structural surface, and to provide a method that can overcome the difficulties such as low strength and easy cracking of soft rock mass, and realize quantitative measurement of mechanical properties and material migration of soft rock mass and its structural surface under shear seepage coupling.

[0010] The purpose of the present invention can be achieved by the following technical solutions:

[0011] According to a first aspect of the present invention, a method for preparing a soft rock sample is provided, the method comprising the following steps:

[0012] Placing a single-sided sample on a sample preparation device, wherein the sample preparation device comprises a silicone mold and a sample sheath and a wedge-shaped pad disposed in the silicone mold;

[0013] Adjust the position of the wedge-shaped pad so that the structural surface of the single-sided specimen is flush with the side of the specimen sheath away from the wedge-shaped pad;

[0014] Prepare high-strength and low-permeability casting materials, pour the casting materials into the gap between the sample and the sample preparation device until it is completely filled, and cure until the strength of the casting materials is stable;

[0015] Remove the silicone mold and wedge-shaped spacer, and fill the gap formed by the wedge-shaped spacer;

[0016] Check the flatness of the prepared sample and end the preparation.

[0017] As a preferred technical solution, after the pouring and filling of the casting material is completed, the bubbles are discharged by a vacuum method.

[0018] According to a first aspect of the present invention, there is provided a device for preparing soft rock samples, which is used to implement the above-mentioned sample preparation method, and comprises: a silicone mold for protection and support, a wedge-shaped pad for adjusting the position of the sample, and a sample sheath for fixing and protecting the sample; the sample sheath comprises a steel keel, and the steel keel is provided with reinforcing ribs and reinforcing enclosures; the wedge-shaped pad is arranged on one side of the sample sheath close to the silicone mold.

[0019] As a preferred technical solution, the reinforcing ribs include a first reinforcing rib located close to the wedge-shaped pad and a second reinforcing rib on the other side, and the reinforcing enclosure is located on the steel keel on the side of the sample sheath away from the wedge-shaped pad.

[0020] As a preferred technical solution, the reinforced enclosure includes a first reinforced enclosure and a second reinforced enclosure, and the end of the second reinforced enclosure is provided with a small hole for easy pouring of casting materials.

[0021] As a preferred technical solution, the first reinforcing ribs include cross reinforcing ribs for sample positioning and first width reinforcing ribs.

[0022] As a preferred technical solution, the device also includes a reserved slot for fluid inlet and outlet; the reserved slot is located on the side of the sample sheath close to the reinforced enclosure.

[0023] According to the third aspect of the present invention, a shear seepage coupling test method for a weak rock mass is provided, and the shear seepage coupling test method for a weak rock mass is used to perform a shear seepage coupling test on the weak rock mass prepared by the above-mentioned sample preparation method, and measure the test data at the water inlet and the water outlet for mutual verification, and obtain the mass loss of the weak rock mass during the shear process by calculating the fluid density at the water outlet; the test data include mass data at two moments before and after the water inlet and the water outlet, density data at two moments before and after the water inlet and the water outlet, the fluid volume at the water inlet, and the fluid volume at the water outlet.

[0024] As a preferred technical solution, the detailed steps of the test method include:

[0025] Two prepared single-sided specimens are placed in an upper shear box and a lower shear box respectively with their structural surfaces facing each other to obtain test specimens; a first sealing seam and a second sealing seam are provided at the joint of the upper shear box and the lower shear box; the first sealing seam refers to a sealing seam close to the tangential end of the testing machine, and the second sealing seam refers to a sealing seam away from the tangential end of the testing machine;

[0026] The sealing material is embedded in the second sealing seam, and the sealing sheet is fastened in the first sealing seam using a sealing fixture; the sealing fixture comprises a sealing reaction frame, which covers the second sealing seam and squeezes the sealing sheet through the sealing reaction frame;

[0027] The sealing fixture is gradually adjusted so that the positive stress generated by the sealing reaction frame on the test specimen exceeds the specified multiple of the maximum water pressure, and the installation is completed;

[0028] Preload the test machine, empty all bubbles in the test machine, conduct shear seepage coupling test on weak rock mass, measure the test data of water inlet and outlet for data analysis;

[0029] After the test is completed, the test samples are taken out to analyze the structural surface.

[0030] As a preferred technical solution, the analysis process of mass loss during shearing of soft rock mass comprises the following steps:

[0031] Acquire test data, and cross-check the test data of the water inlet with the test data of the water outlet;

[0032] Calculate the real-time fluid density of the fluid at the outlet, the expression is:

[0033]

[0034] Among them, ρ out Indicates the fluid density at the outlet; M 1out Indicates the quality data of the water outlet at the previous moment; M 2out Indicates the quality data of the water outlet at the next moment; Q out Indicates the fluid volume at the outlet;

[0035] Using real-time fluid density difference △ρ=ρ out -ρ in Indicates real-time mass loss, plots fluid density difference curve and cumulative mass loss curve; where ρ in Represents the fluid density at the water inlet.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] 1) The present invention provides a sample preparation method and a device for sample preparation that can protect the integrity of soft rock samples; the sample sheath keel in the device is used to bear the positive stress of the water-stopping material, effectively seal and stop water, and completely avoid the damage of the soft rock or soft rock structure surface samples caused by the pressure or the influence on the test results; the sample sheath reinforcement rib is used as a baffle to extend the seepage path; the soft rock and its structure surface samples are semi-wrapped and reinforced by high-strength and low-permeability materials, so as to avoid the structural collapse of the sample during the test and obtain the shear curve of the whole process; the sample prepared by the preparation method can be suitable for the test equipment for hard rock and hard rock structure surface, avoiding the influence of large deformation of the soft rock or even rock destruction caused by traditional high-pressure sealing, and ensuring the accuracy of the test;

[0038] 2) The present invention establishes a method for quantitatively measuring the amount of material migration of soft rock mass and its structural surface under the shear seepage coupling effect. The material migration of soft rock mass is measured in real time by two electronic scales and two densitometers during the test process, providing a scientific basis for engineering and geological disaster prevention involving soft rock mass;

[0039] 3) The present invention proposes a sealing method suitable for soft rock mass, which uses a sealing sheet and a sealing fixture at the first sealing seam to replace the traditional high-pressure sealing device, thereby avoiding the influence of large deformation of the soft rock mass or even rock mass destruction caused by the traditional high-pressure sealing, thereby ensuring the accuracy of the test;

[0040] 4) The present invention has a wide range of applications. The semi-wrapped reinforcement sample preparation method is used to prepare test samples. The method is applicable to all types of soft rock masses, including soft rock masses with relatively complete initial structures, soft rock masses in a loose and fragmented state in the initial state, and rock samples with soft and hard interlayers.

[0041] 5) The present invention can truly restore the actual state of the shear seepage process of soft rock mass. By semi-wrapping and reinforcing the soft rock mass and its structural surface samples with high-strength and low-permeability materials, the samples are subject to lateral constraints, and the large shear deformation is concentrated in the shear zone, making the test closer to the shear seepage state under the natural state. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the sample preparation device of the present invention after installation;

[0043] Figure 2 2a is a schematic diagram of a sample after preparation according to the present invention; (2a) is a longitudinal cross-sectional diagram of the sample after preparation; (2b) is a transverse cross-sectional diagram of the sample after preparation;

[0044] Figure 3 Schematic diagram of the sample sheath shooting of the present invention; (3a) is a front view of the sample sheath; (3b) is a left view of the sample sheath; (3c) is a top view of the sample sheath; (3d) is a cross-sectional view of the sample sheath along AA;

[0045] Figure 4 Schematic diagram of the test sample of the present invention; (4a) is a longitudinal cross-sectional view of the test sample; (4b) is a transverse cross-sectional view of the test sample;

[0046] Figure 5 It is a schematic diagram of the quantitative testing device of the present invention.

[0047] Reference numerals:

[0048] 1-first reinforcement enclosure, 2-second reinforcement enclosure, 3-second length reinforcement rib, 4-second width reinforcement rib, 5-reserved gap, 6-cross reinforcement rib, 7-first width reinforcement rib, 8-steel keel, 10-silicone mold, 11-sample sheath, 12-single-sided sample, 13-wedge-shaped pad, 14-casting gap, 15-casting material, 16-test sample, 17-testing machine, 18-axial loading module, 19-high-pressure servo piston pump, 2 0-water inlet liquid storage tank, 21-water inlet density meter, 22-water inlet electronic balance, 23-control computer, 24-water outlet liquid storage tank, 25-water outlet density meter, 26-water outlet electronic balance, 27-tangential loading terminal, 28-water inlet water injection pipe, 29-water outlet water injection pipe, 30-sealing fixture, 31-water inlet flow meter, 32-water outlet flow meter, 33-sealing sheet, 34-sealing fixture pad, 35-sealing reaction frame. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0050] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0051] Embodiment 1:

[0052] This embodiment provides a method for preparing a soft rock sample, which comprises the following steps:

[0053] S1. Place the single-sided sample 12 on a sample preparation device such as Figure 1 As shown, the sample preparation device includes a silicone mold 10 and a sample sheath 11 and a wedge-shaped pad 13 arranged in the silicone mold 10;

[0054] S2, adjust the position of the wedge-shaped pad 13 so that the structural surface of the single-sided sample 12 is aligned with the sample sheath 11, according to Figure 1 The side away from the wedge-shaped pad 13 is shown flush;

[0055] S3, prepare high-strength and low-permeability casting material 15, pour the casting material 15 into the casting gap 14 between the sample and the sample preparation device until it is completely filled and the bubbles are discharged by vacuum method, and cure until the strength of the casting material 15 is stable;

[0056] S4, remove the silicone mold 10 and the wedge-shaped pad 13, and fill the gap formed by the wedge-shaped pad 13;

[0057] S5. Check the flatness of the prepared sample and end the preparation. Figure 2 As shown, Figure (2a) is a schematic diagram of a longitudinal section, and Figure (2b) is a schematic diagram of a transverse section.

[0058] Embodiment 2:

[0059] The above is an introduction to a method embodiment. The following is a further explanation of the solution of the present invention through an apparatus embodiment.

[0060] like Figure 3 As shown, Figure (3a) is a front view of the sample sheath, Figure (3b) is a left view of the sample sheath, Figure (3c) is a top view of the sample sheath, and Figure (3d) is a cross-sectional view of the sample sheath along AA; the sample preparation device includes: a silicone mold 10 for protection and support, a wedge-shaped pad 13 for adjusting the position of the sample, and a sample sheath 11 for fixing and protecting the sample; wherein, the sample sheath 11 is placed in the silicone mold 10, and the wedge-shaped pad 13 is arranged on one side of the sample sheath 11 close to the silicone mold 10; the sample sheath 11 includes a steel keel 8, and the steel keel 8 is provided with reinforcing ribs and reinforcing enclosures, and the specifications of the sample sheath 11 are: 200 mm long, 100 mm wide, and 50 mm high.

[0061] Among them, the reinforced enclosure includes a first reinforced enclosure 1 and a second reinforced enclosure 2 located on the side of the sample sheath 11 away from the wedge-shaped pad 13. The end of the second reinforced enclosure 2 is provided with a small hole for pouring the casting material 15, and a reserved gap 5 for fluid entry and exit is provided near the reinforced enclosure side; the specifications of the first reinforced enclosure 1 are: 200m long and 6mm wide; the specifications of the second reinforced enclosure 2 are: 100mm long and 8mm wide.

[0062] The reinforcing ribs include a first reinforcing rib located near the wedge-shaped pad 13 and a second reinforcing rib on the other side, wherein the first reinforcing rib includes a cross reinforcing rib 6 and a first width reinforcing rib 7 , and the second reinforcing rib includes a second length reinforcing rib 3 and a second width reinforcing rib 4 .

[0063] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the described module can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0064] Embodiment 3:

[0065] The present embodiment provides a shear seepage coupling test method for a weak rock mass, which is used to perform a shear seepage coupling test on the weak rock mass prepared by the above-mentioned sample preparation method, and measure the test data of the water inlet and the water outlet for mutual verification, and obtain the mass loss of the weak rock mass during the shear process by calculating the fluid density at the water outlet; the test data include mass data at two moments before and after the water inlet and the water outlet, density data at two moments before and after the water inlet and the water outlet, the fluid volume at the water inlet, and the fluid volume at the water outlet.

[0066] The test method uses a test machine 17 to conduct a shear seepage test on a weak rock mass, wherein the test machine 17 can be a biaxial loading test machine or a common shear seepage test machine. In the present invention, a biaxial loading test machine is used, and the test machine 17 includes an axial loading module 18, a high-pressure servo plunger pump 19, a water outlet liquid storage tank 20, a water inlet density meter 21, a water inlet electronic balance 22, a control computer 23, a water outlet liquid storage tank 24, a water outlet density meter 25, a water outlet electronic balance 26, a tangential loading end 27, a water inlet water injection pipe 28, a water outlet water injection pipe 29, a sealing fixture 30, a water inlet flowmeter 31, a water outlet flowmeter 32 and a sealing sheet 33; wherein the sealing fixture 30 includes a sealing fixture pad 34 and a sealing reaction frame 35.

[0067] The detailed steps of the test method include:

[0068] A1. Place two prepared single-sided specimens with their structural surfaces facing each other into the upper shear box and the lower shear box to obtain test specimen 16. Figure 4 As shown, FIG. (4a) is a longitudinal cross-sectional view, and FIG. (4b) is a transverse cross-sectional view;

[0069] A first sealing seam and a second sealing seam are provided at the joint of the upper shear box and the lower shear box. The first sealing seam refers to the sealing seam on the side of the tangential end 27 close to the testing machine 17, and the second sealing seam refers to the sealing seam on the side of the tangential end 27 away from the testing machine 17.

[0070] A2, embed the sealing material into the second sealing seam, and use the sealing fixture 30 to fasten the sealing sheet 33 in the first sealing seam; the sealing fixture 30 covers the second sealing seam and squeezes the sealing sheet 33 through the sealing reaction frame 35;

[0071] A3. Gradually adjust the sealing fixture 30 so that the positive stress generated by the sealing reaction frame 35 on the test specimen 16 exceeds twice the maximum water pressure. Figure 5 As shown;

[0072] A4. Add the fluid medium of the seepage shear test into the water inlet storage tank 20, preload the testing machine 17, and use the high-pressure servo plunger pump 19 to inject the fluid to empty all bubbles in the testing machine 17.

[0073] A5. Start the testing machine 17, apply axial load or constraint according to the set loading program, and after reaching the target value, officially start the shear seepage coupling test, and record the water pressure and flow rate at the inlet and outlet, the mass and density change of the liquid storage tank at the inlet and outlet, and the mechanical deformation data such as axial load and shear displacement until the end of the test;

[0074] A6. After the test, remove the test sample 16 and conduct further analysis on its structural surface. After the test analysis is completed, knock off the inclusion material to remove the sealing sheath and use it for subsequent sample preparation.

[0075] In the process of analyzing the mass loss during the shearing of soft rock mass, multiple dimensional data are used for mutual verification. For the mass data and density data measured at the water inlet, the results meet the following requirements:

[0076]

[0077] Among them, M 1in , M 2in Respectively represent the data measured by the electronic balance at two moments before and after the water inlet; ρ 1in , ρ 2in They represent the results obtained by the density meter at two moments before and after the water inlet respectively; represents the total volume of fluid passing through the inlet between two moments, Q ib To inject flow;

[0078] For the mass data and density data measured at the outlet, the results satisfy:

[0079]

[0080] Among them, M 1out , M 2out Respectively represent the data measured by the electronic balance at two moments before and after the water outlet; ρ 1out , ρ 2out Respectively represent the results obtained by the density meter at two moments before and after the water outlet; Represents the total volume of fluid passing through the outlet between two moments; Q out The outflow flow.

[0081] It can be assumed that the density and volume of the fluid will not change from the inlet storage tank 20 through the high-pressure servo plunger pump 19 to the injection into the sample. Therefore, the key to calculating the mass loss during the shearing process of weak rock mass is to calculate the fluid density at the outlet, thereby obtaining a real-time fluid density difference curve and a cumulative mass loss curve.

[0082] The real-time density of the fluid at the outlet can be calculated as follows:

[0083]

[0084] Among them, ρ out Indicates the fluid density at the outlet;

[0085] The real-time mass loss can be expressed as the real-time fluid density difference:

[0086] Δρ=ρ out -ρ in

[0087] Where Δρ represents the real-time fluid density difference.

[0088] The above-mentioned real-time data on mass loss can be jointly analyzed with the normal load-shear displacement curve, hydraulic opening-shear displacement curve, shear stress-shear displacement curve, etc. in traditional shear seepage research, which will not be elaborated here.

[0089] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for preparing a soft rock sample, characterized in that: The preparation method comprises the following steps: Placing a single-sided sample (12) in a sample preparation device, wherein the sample preparation device comprises a silicone mold (10) and a sample sheath (11) and a wedge-shaped pad (13) arranged in the silicone mold (10); The position of the wedge-shaped pad (13) is adjusted so that the structural surface of the single-sided specimen (12) is flush with the side of the specimen sheath (11) away from the wedge-shaped pad (13); Preparing a high-strength and low-permeability casting material (15), pouring the casting material (15) into the casting gap (14) between the sample and the sample preparation device until it is completely filled, and curing until the strength of the casting material (15) is stable; Remove the silicone mold (10) and the wedge-shaped spacer (13), and fill the gap formed by the wedge-shaped spacer (13); Check the flatness of the prepared sample and end the preparation.

2. A method for preparing a soft rock sample according to claim 1, characterized in that: After the pouring and filling of the casting material (15) is completed, the bubbles are discharged by a vacuum method.

3. A soft rock sample preparation device, characterized in that: The device is used to implement the sample preparation method of any one of claims 1 or 2, comprising: a silicone mold (10) for protection and support, a wedge-shaped pad (13) for adjusting the position of the sample, and a sample sheath (11) for fixing and protecting the sample; the sample sheath (11) comprises a steel keel (8), and the steel keel (8) is provided with reinforcing ribs and reinforcing enclosures; the wedge-shaped pad (13) is arranged on one side of the sample sheath (11) close to the silicone mold (10).

4. A soft rock sample preparation device according to claim 3, characterized in that: The reinforcing ribs include a first reinforcing rib located close to the wedge-shaped pad (13) and a second reinforcing rib on the other side, and the reinforcing enclosure is located on the steel keel (8) on the side of the sample sheath (11) away from the wedge-shaped pad (13).

5. A soft rock sample preparation device according to claim 4, characterized in that: The reinforced enclosure comprises a first reinforced enclosure (1) and a second reinforced enclosure (2), and the end of the second reinforced enclosure (2) is provided with a small hole for facilitating the pouring of casting material (15).

6. A soft rock sample preparation device according to claim 4, characterized in that: The first reinforcing ribs include cross reinforcing ribs (6) for sample positioning and first width reinforcing ribs (7).

7. A soft rock sample preparation device according to claim 3, characterized in that: The device also includes a reserved slit (5) for fluid to enter and exit; the reserved slit (5) is located on the side of the sample sheath (11) close to the reinforced enclosure.

8. A shear seepage coupling test method for soft rock mass, characterized in that: The soft rock shear seepage coupling test method is used to carry out a shear seepage coupling test on the soft rock mass prepared by any of the sample preparation methods in claim 1 or 2, and to measure the test data at the water inlet and the water outlet for mutual verification, and to obtain the mass loss of the soft rock mass during the shear process by calculating the fluid density at the water outlet; the test data include mass data at two moments before and after the water inlet and the water outlet, density data at two moments before and after the water inlet and the water outlet, the fluid volume at the water inlet, and the fluid volume at the water outlet.

9. A soft rock mass shear seepage coupling test method according to claim 8, characterized in that: The detailed steps of the test method include: Two prepared single-sided specimens are placed in an upper shear box and a lower shear box respectively with their structural surfaces facing each other to obtain a test specimen (16); a first sealing seam and a second sealing seam are provided at the joint of the upper shear box and the lower shear box; the first sealing seam refers to a sealing seam on the side of the tangential end (27) close to the test machine (17), and the second sealing seam refers to a sealing seam on the side of the tangential end (27) away from the test machine (17); The sealing material is embedded in the second sealing seam, and the sealing sheet (33) is fastened in the first sealing seam using a sealing fixture (30); the sealing fixture (30) comprises a sealing reaction frame (35) which covers the second sealing seam and squeezes the sealing sheet (33) through the sealing reaction frame (35); The sealing fixture (30) is gradually adjusted so that the normal stress generated by the sealing reaction frame (35) on the test specimen (16) exceeds a specified multiple of the maximum water pressure, and the installation is completed; Preloading the testing machine (17), emptying all bubbles in the testing machine (17), and then conducting a shear seepage coupling test on a weak rock mass, measuring the test data of the water inlet and the water outlet for data analysis; After the test is finished, the test sample (16) is taken out to analyze the structural surface.

10. A shear seepage coupling test method for weak rock mass according to claim 8, characterized in that: The analysis process of mass loss during shearing of soft rock mass comprises the following steps: Acquire test data, and cross-check the test data of the water inlet with the test data of the water outlet; Calculate the real-time fluid density of the fluid at the outlet, the expression is: Among them, ρ out is the fluid density at the outlet; M 1out is the quality data of the water outlet at the previous moment; M 2out is the quality data of the water outlet at the next moment; Q out is the outlet fluid volume; Using real-time fluid density difference Δρ=ρ out -ρ in represents the real-time mass loss, plots the fluid density difference curve and the cumulative mass loss curve; where ρ in is the density of the fluid at the inlet.

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