Nonlinear seepage flow velocity equivalent testing device and method for simulating fractured rock mass

Abstract

The invention belongs to the field of experimental research of rock seepage, and provides a non-linear seepage flow velocity equivalent testing device for simulating fractured rock mass, which comprises a water storage container, a water supply part, a pressure measuring part, a pore matrix part and a through fracture, the output end of the water supply part is communicated with the water storage container, and the water storage container is communicated with the pressure measuring part and the pore matrix part; the pore matrix part is filled with a pore matrix, the pore matrix is of a hollow cylindrical structure, the hollow part of the pore matrix forms the through crack, and the through crack is blocked or partially filled; the pore matrix part is provided with a drainage chamber, and a water source in the water storage container enters the drainage chamber through the pore matrix; according to the method, the change condition of the flow velocity of the rock mass with the through cracks at the through cracks can be effectively measured, the seepage flow containing the through cracks can be accurately calculated, and the change rule of the non-linear seepage flow velocity is provided.

Description

Technical Field

[0001] The invention belongs to the field of experimental research on rock seepage, and in particular relates to a nonlinear seepage velocity equivalent testing device and method for simulating fractured rock mass. Background Art

[0002] The through and non-through cracks, pipes and pore structures in the soil together constitute a complex porous network system. Among them, the through pipe cracks are the main path for the conversion between groundwater and surface water, the important channel for the hydraulic connection between groundwater and rock and soil, and the boundary condition that is often tracked by the instability and failure of rock and soil.

[0003] Since the microstructure of the cracks and pores that make up porous media is extremely complex and irregular, statistical methods are usually used only from a macroscopic perspective when studying seepage problems. That is, the average flow velocity and pressure of the fluid flow on the seepage section (the formation section perpendicular to the fluid flow direction) are mainly studied, rather than studying the flow conditions in individual cracks and pores.

[0004] At present, the seepage velocity test mainly measures the flow velocity and permeability of a fixed cross-section, and there has been no discussion on the changes in the seepage velocity and permeability with the distance from the through-fracture. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a nonlinear seepage velocity equivalent test device and method for simulating fractured rock mass to solve the problems in the prior art. The technical solution adopted by the present invention is: A nonlinear seepage flow velocity equivalent test device for simulating fractured rock mass, comprising: a water storage container, a water supply part, a pressure measuring part, a pore matrix part and a through fracture; The output end of the water supply part is connected to the water storage container, and the water storage container is connected to the pressure measuring part and the porous matrix part; The porous matrix part is filled with a porous matrix, the porous matrix is ​​a hollow cylindrical structure, the hollow part of the porous matrix forms the through cracks, and the through cracks are blocked or partially filled; The porous matrix part is provided with a drainage chamber, and the water source in the water storage container enters the drainage chamber through the porous matrix.

[0006] Furthermore, the porous matrix part includes a water guide box body, a middle frame body and a drainage box body; The water guide box is provided with a cavity opening upward, the cavity is connected to the water storage container through a water inlet pipe, the top of the water guide box is detachably connected to the middle frame, and the top of the middle frame is detachably connected to the drainage box; The middle frame is a hollow structure, the bottom of the middle frame is fixedly connected to the bottom grid plate, a plurality of partition grid plates are arranged inside the middle frame, the partition grid plates are hollow cylindrical structures, the bottom of the partition grid plates is fixedly connected to the bottom grid plate, a plurality of the partition grid plates are nested and coaxially distributed, the outer diameters of the plurality of the partition grid plates increase from the inside to the outside, the plurality of the partition grid plates divide the interior of the middle frame into a plurality of filling cavities, the filling cavities are filled with the porous matrix; the interior of the partition grid plate located in the middle is not filled with the porous matrix and the through cracks are formed; A plurality of drainage chambers are arranged in the drainage box, and the plurality of drainage chambers are connected to the filling cavity and the through cracks in a one-to-one correspondence.

[0007] Furthermore, a plurality of annular baffles are fixedly connected in the drainage box body, and the plurality of annular baffles divide the interior of the drainage box body into a plurality of drainage chambers of annular structures; drainage holes corresponding to the plurality of drainage chambers are arranged at the bottom of the drainage box body, and the drainage holes connect the drainage chamber and the filling chamber; and drainage pipes corresponding to the plurality of drainage chambers are fixedly arranged at the top of the drainage box body.

[0008] Furthermore, it also includes a grouting shaft body, and the partition grid plate located in the middle is sleeved on the grouting shaft body, and a gap is distributed between the inner wall surface of the partition grid plate and the outer surface of the grouting shaft body, and the gap is used to fill part of the filling matrix to form a partially filled through crack.

[0009] Furthermore, a first threaded hole is provided on the bottom grid plate, a second threaded hole is provided on the drainage box body, and the grouting shaft body is threadedly connected to the first and second threaded holes; The grouting shaft body is provided with a blind hole opening upward, and the side wall of the grouting shaft body is provided with a waist-shaped hole communicating with the blind hole; a drainage grouting pipe is provided on the top of the drainage box body, and a switch valve is provided on the drainage grouting pipe; The drainage grouting pipe is used to inject the part of the filling matrix into the gap on the outer side of the grouting shaft body, and is used to form the blocked through crack when the switch valve is closed.

[0010] Furthermore, the pressure measuring part includes a pressure measuring tube, a stopper, a slider, a spring and a piston; The pressure measuring tube is arranged vertically, and its bottom is connected to the water storage container. The piston is arranged in the pressure measuring tube, and the piston is a hollow structure. The slider can slide through the inside of the piston. The top and bottom of the slider are both T-shaped structures. The spring is arranged below the T-shaped structure at the top of the slider, and the spring is sleeved on the slider. The T-shaped structure at the bottom of the slider abuts against the bottom surface of the piston. The slider is provided with a guide hole with an upward opening, a through hole connected to the guide hole is provided on the side of the slider, the inner wall surface of the piston blocks the through hole, the stopper is provided above the slider, and the stopper is provided with a pressure relief hole adapted to the guide hole; When the piston rises until the slider abuts against the stopper, the slider moves downward, causing the through hole to move downward away from the piston, thereby allowing the through hole, the flow guide hole and the pressure relief hole to communicate with the portion of the pressure measuring tube located below the piston; The pressure measuring tube is provided with scale lines for measuring pressure.

[0011] A nonlinear seepage velocity equivalent test method for simulating fractured rock mass comprises the following steps: Step 1: Arrange the test device, the water supply part, the water storage container, and the porous matrix part are connected in sequence, the water storage container is connected to the pressure measuring part, the porous matrix part is filled with porous matrix, and through cracks are set; Step 2: The water supply part supplies water to the water storage container, and the water pressure of the water storage container is observed by the pressure measuring part, and the water output of each drainage chamber is collected. The water volume of each drainage chamber is recorded as V , V , V … V n , calculate the average flow velocity in the drainage chamber through the flow rate, and draw the flow velocity distribution curve; Step 3: After the test, take out the porous matrix and determine the porosity of the converted porous matrix according to the geotechnical test standard. n and water permeability K , which passed the test K and n The velocity distribution of the porous matrix is ​​calculated based on the values ​​and characteristic dimensions of the model.

[0012] Furthermore, in step one, the through-crack is blocked or partially filled. When partially filled, an axis is placed in the through-crack to form a gap with the inner wall of the through-crack, and a part of the filling matrix is ​​filled in the gap. Then the axis is taken out to form a partially filled through-crack.

[0013] Furthermore, in step 3, the porosity n and water permeability K Obtained by the following formula: , Where: Q is the amount of water flowing through the porous matrix part; L is the length of the porous matrix; A is the cross-sectional area of ​​the porous matrix; is the hydraulic head difference at both ends of the porous matrix, in units of m ; t The test period; , Where: V 0 is the volume of the porous matrix; the unit is m m 2 is the mass of the pore matrix in water at saturation; m 1 is the mass of the porous matrix in the dry state.

[0014] The present invention has the following beneficial effects: the present invention proposes a nonlinear seepage velocity equivalent testing device for through-fracture rock mass, which is easy to manufacture, has a simple, economical and repeatable testing method, can effectively measure the change of the velocity of the through-fracture rock mass at the through-fracture, can more accurately calculate the seepage flow containing the through-fracture, and proposes the change law of the nonlinear seepage velocity. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram showing the principle of the device of the present invention; Figure 2 is a schematic diagram of a permeability curve of the present invention; Figure 3 It is a schematic diagram of the specific structure of the present invention; Figure 4 is a schematic diagram of the porous matrix part; Figure 5 It is a schematic diagram when the through crack is partially filled; Figure 6 It is a schematic diagram of the pressure measurement part; Figure 7 It is a schematic diagram of the pressure measuring part when the pressure is released. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention Figure 1-Figure 7 , the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0017] like Figure 1-Figure 3 , a nonlinear seepage flow velocity equivalent test device for simulating fractured rock mass, comprising: a water storage container 1, a water supply part 2, a pressure measuring part 3, a porous matrix part 4 and a through fracture 8; The output end of the water supply part 2 is connected to the water storage container 1, and the water storage container 1 is connected to the pressure measuring part 3 and the porous matrix part 4; The porous matrix part 4 is filled with a porous matrix 406, and the porous matrix 406 is a hollow cylindrical structure. The hollow part of the porous matrix 406 forms the through crack 8, and the through crack 8 is blocked or partially filled; The porous matrix portion 4 is provided with a drainage chamber, and the water source in the water storage container 1 enters the drainage chamber through the porous matrix 406 .

[0018] The water supply part 2 is a prior art, which can be a water tank, which outputs a pressurized water source to the water storage container 1 through a pump body. The pressure measuring part 3 is used to monitor the real-time pressure of the water storage container 1. The through crack 8 includes two states, namely, the state where the interior is hollow and not filled, the upper and lower ends are blocked, or the state where it is partially filled. The two states need to be tested separately. The water supply part 2 can be connected to the water storage container 1 through the water inlet pipe 7. Multiple drainage chambers can be connected to containers such as beakers through drainage pipes 410 to collect drainage. According to the different water volumes, the nonlinear seepage velocity and permeability of the porous matrix 406 can be intuitively judged; or the average flow velocity of the drainage chamber can be calculated by the flow rate.

[0019] In the present invention, a portion of the water source directly enters the drainage chamber through the porous matrix or the through cracks 8, and another portion of the water source enters the drainage chamber after passing through the porous matrix 406 and then entering the through cracks 8. Figure 2 , the further to the middle, the higher the permeability of the porous matrix 406.

[0020] like Figure 4 The porous matrix part 4 includes a water guide box 401 with a cylindrical outer surface, a middle frame 402 and a drainage box 403; The water guide box 401 is provided with a cavity opening upward, and the cavity is connected to the water storage container 1 through the water inlet pipe 6. The top of the water guide box 401 is detachably connected to the middle frame 402 through bolts, buckles, etc., and the top of the middle frame 402 is detachably connected to the drainage box 403 through bolts, buckles, etc.; The middle frame 402 is a hollow structure, the bottom of the middle frame 402 is fixedly connected to the bottom grid plate 404, a plurality of partition grid plates 405 are arranged inside the middle frame 402, the partition grid plates 405 are hollow cylindrical structures, the bottom of the partition grid plates 405 is fixedly connected to the bottom grid plate 404, a plurality of the partition grid plates 405 are nested and coaxially distributed, the outer diameters of the plurality of the partition grid plates 405 increase from the inside to the outside, and the plurality of the partition grid plates 405 divide the interior of the middle frame 402 into a plurality of filling cavities, and the filling cavities are filled with the porous matrix 406; the interior of the partition grid plate 405 located in the middle is not filled with the porous matrix 406 and forms the through crack 8; A plurality of drainage chambers are arranged in the drainage box 403 , and the plurality of drainage chambers are connected to the filling cavity and the through crack 8 in a one-to-one correspondence.

[0021] The bottom grid plate 404 and the partition grid plate 405 are both mesh plate structures, and can also be components such as screens. An annular filling cavity is formed between the inner and outer walls of adjacent partition grid plates 405. The drainage chamber is annular, and its structure, position, and number are adapted to the filling cavity.

[0022] The water inlet pipe 6 is filled with water into the water guide box 401, the liquid level of the water guide box 401 rises, and the water source passes through the bottom grid plate 404 upward into the porous matrix 406 and the through crack 8 to start the penetration test. Multiple filling cavities can be filled with the same porous matrix 406, or a porous matrix 406 with gradually changing pores.

[0023] Furthermore, a plurality of annular baffles 408 are fixedly connected inside the drainage box 403, and the plurality of annular baffles 408 divide the interior of the drainage box 403 into a plurality of drainage chambers of annular structures; drainage holes 409 corresponding to the plurality of drainage chambers are arranged at the bottom of the drainage box 403, and the drainage holes 409 connect the drainage chamber and the filling chamber; and a drainage pipe 410 corresponding to the plurality of drainage chambers is fixedly arranged at the top of the drainage box 403.

[0024] The drain pipe 410 outputs the infiltrated water, and the drain pipe 410 can be connected to a corresponding collection container, such as a beaker.

[0025] Furthermore, it also includes a grouting shaft 413, and the partition grid plate 405 located in the middle is sleeved on the grouting shaft 413. There is a gap between the inner wall surface of the partition grid plate 405 and the outer side surface of the grouting shaft 413, and the gap is used to fill part of the filling matrix 407 to form a partially filled through crack 8.

[0026] Furthermore, a first threaded hole is provided on the bottom grid plate 404, a second threaded hole is provided on the drainage box 403, and the grouting shaft 413 is threadedly connected to the first and second threaded holes; The grouting shaft 413 is provided with a blind hole opening upward, and the side wall of the grouting shaft 413 is provided with a waist-shaped hole 414 connected to the blind hole; a drainage grouting pipe 411 is provided on the top of the drainage box 403, and a switch valve 412 is provided on the drainage grouting pipe 411; The drainage grouting pipe 411 is used to inject the partial filling matrix 407 into the gap on the outer side of the grouting shaft 413, and is used to form the blocked through crack 8 when the switch valve 412 is closed.

[0027] The grouting shaft 413 can be connected to the first and second threaded holes by waterproof tape, paint, etc. to form a sealing function to block the through crack 8. The bottom of the drainage grouting pipe 411 is inserted into the top of the blind hole of the grouting shaft 413. The top of the drainage grouting pipe 411 can be connected to a corresponding collection container or a grouting funnel through a three-way valve to collect the discharged water source and inject part of the filling matrix 407 into the through crack 8.

[0028] like Figure 4 At this time, the part of the filling matrix 407 is not filled, and the switch valve 412 is in a closed state. At this time, the water source in the through crack 8 is blocked and cannot be discharged through the drainage grouting pipe 411. Figure 4 In the test state, what is tested is the through-crack 8 in the blocked state. In this state, the permeability is the permeability of the pore matrix 406 , excluding the part that penetrates into the through-crack 8.

[0029] like Figure 5 When the partially filled through cracks 8 need to be tested, the switch valve 412 is in an open state, and the partially filled matrix 407 is injected into the outer side of the grouting shaft 413 using a funnel or other components. The partially filled matrix 407 is between the outer side of the partially filled matrix 407 and the inner wall of the middle partition grid plate 405, and a partially filled layer of a hollow structure is formed at the partially filled matrix 407. The switch valve 412 is kept open, and the grouting shaft 413 is removed to start the permeability test of the partially filled through cracks 8. First, the water guide box 401 is removed, and then the grouting shaft 413 is taken out, and the grouting shaft 413 is cleaned and set aside.

[0030] The drainage grouting pipe 411 and the grouting shaft 413 of the present invention can be used for both drainage and grouting, and can form a uniform and stable partial filling layer.

[0031] exist Figure 5When testing, water sources have the following paths: 1. Water sources enter the porous matrix 406 from bottom to top and are discharged; 2. Water sources enter the through-cracks 8 from bottom to top and are discharged; 3. Water sources pass through the porous matrix 406 and the partially filled matrix 407 in the radial direction from the periphery to the middle, and then enter the through-cracks 8 and are discharged.

[0032] Therefore, when the partially filled through-crack 8 of the present invention is tested, a nonlinear test environment can be formed for testing the nonlinear seepage velocity, which is more in line with the actual situation.

[0033] like Figure 5-Figure 6 The pressure measuring part 3 includes a pressure measuring tube 301, a stopper 302, a slider 304, a spring 306 and a piston 307; The pressure measuring tube 301 is vertically arranged, and its bottom is connected to the water storage container 1. The piston 307 is arranged in the pressure measuring tube 301. The piston 307 is a hollow structure. The slider 304 can slide through the inside of the piston 307. The top and bottom of the slider 304 are both T-shaped structures. The spring 306 is arranged below the T-shaped structure at the top of the slider 304. The spring 306 is sleeved on the slider 304. The T-shaped structure at the bottom of the slider 304 abuts against the bottom surface of the piston 307. The slider 304 is provided with a guide hole 305 with an opening facing upward, a through hole 308 connected to the guide hole 305 is provided on the side of the slider 304, the inner wall surface of the piston 307 blocks the through hole 308, the stopper 302 is provided above the slider 304, and the stopper 302 is provided with a pressure relief hole 303 adapted to the guide hole 305; When the piston 307 rises until the slider 304 abuts against the stopper 302, the slider 304 moves downward, causing the through hole 308 to move downward away from the piston 307, so that the through hole 308, the guide hole 305 and the pressure relief hole 303 are connected to the portion of the pressure measuring tube 301 located below the piston 307; The pressure measuring tube 301 is provided with scale lines for measuring pressure.

[0034] When water is filled into the water storage container 1, a certain water pressure is formed. At this time, the water source in the pressure measuring tube 301 and below the piston 307 pushes the piston 307 to move upward. Since the slider 304 is subjected to the upward thrust of the water source and the thrust of the spring 306, the through hole 308 remains in the piston 307, so that the piston 307 rises. After the piston 307 rises to a certain height and remains unchanged, the water pressure remains stable, and the water pressure value can be obtained through the scale line on the pressure measuring tube 301.

[0035] When the porous matrix or the drain pipe 8 is blocked, the entire device is abnormal, and the piston 307 continues to rise until the slider 304 hits the stopper 302. Figure 6 At this time, the slider 304 moves downward and the spring 306 is compressed, so the through hole 308 is separated from the piston 307 and is located below the piston 307. At this time, the through hole 308 is connected to the pressure measuring tube 301 on the upper and lower sides of the piston 307, so that the water source enters the through hole 308, the guide hole 305 and the pressure relief hole 303 from the bottom of the pressure measuring tube 301 in turn, and then is discharged from the top of the pressure measuring tube 301 to complete the pressure relief.

[0036] The pressure measuring part 3 of the present invention can perform two functions: pressure measuring and pressure relief. The stopper 302 can be connected to the inside of the pressure measuring tube 301 through a thread to adjust the height of the stopper 302, so as to adjust the maximum pressure relief value. In addition, the water storage container 1 can be connected to the top of the pressure measuring tube 301 through the return pipe 5 to recover the water source.

[0037] A nonlinear seepage velocity equivalent test method for simulating fractured rock mass comprises the following steps: Step 1: Arrange the test device, the water supply part 2, the water storage container 1, and the porous matrix part 4 are connected in sequence, the water storage container 1 is connected to the pressure measuring part 3, the porous matrix part 4 is filled with a porous matrix 406, and a through crack 8 is set; Step 2: The water supply part 2 supplies water to the water storage container 1, and the water pressure of the water storage container 1 is observed by the pressure measuring part 3, and the water output of each drainage chamber is collected. The water volume of each drainage chamber is recorded as V 1 , V 2 , V 3 … V n , calculate the average flow velocity of the drainage chamber through the flow rate, and draw the flow velocity distribution curve, such as Figure 2 ; Step 3: After the test, take out the porous matrix and determine the porosity of the converted porous matrix according to the geotechnical test standard. n and water permeability K , which passed the test K and n The velocity distribution of the porous matrix is ​​calculated based on the values ​​and characteristic dimensions of the model.

[0038] Furthermore, in step 1, the through crack 8 is blocked or partially filled. When partially filled, a shaft is placed in the through crack 8, and a gap is formed between the shaft and the inner wall of the through crack 8. A part of the filling matrix 407 is filled in the gap, and then the shaft is taken out to form a partially filled through crack 8. The shaft is the grouting shaft 413.

[0039] Furthermore, in step 3, the porosity n and water permeability K Obtained by the following formula: , Where: Q is the amount of water flowing through the porous matrix part; L is the length of the porous matrix; A is the cross-sectional area of ​​the porous matrix; is the hydraulic head difference at both ends of the porous matrix, in units of m ; t The test period; , Where: V 0 is the volume of the porous matrix; the unit is m 3 m 2 is the mass of the pore matrix in water at saturation; m 1 is the mass of the porous matrix in the dry state.

[0040] In addition, in the present invention, the partially filled matrix 407 is made by mixing standard sand and cementing material, and the sand grain size is larger than that of the porous matrix 406. The porous matrix 406 can be a multi-porous combined geological unit simulation material in the prior art.

[0041] The embodiments described above are only descriptions of the preferred modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations, modifications, and substitutions made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A nonlinear seepage velocity equivalent test device for simulating fractured rock mass, characterized in that: include: A water storage container (1), a water supply portion (2), a pressure measuring portion (3), a porous matrix portion (4) and a through fracture (8); The output end of the water supply part (2) is connected to the water storage container (1), and the water storage container (1) is connected to the pressure measuring part (3) and the porous matrix part (4); The porous matrix part (4) is filled with a porous matrix (406), the porous matrix (406) is a hollow cylindrical structure, the hollow part of the porous matrix (406) forms the through crack (8), and the through crack (8) is blocked or partially filled; The porous matrix portion (4) is provided with a drainage chamber, and the water source in the water storage container (1) enters the drainage chamber through the porous matrix (406).

2. The nonlinear seepage velocity equivalent test device for simulating fractured rock mass according to claim 1, characterized in that: The porous matrix part (4) comprises a water guide box (401), a middle frame (402) and a drainage box (403); The water guide box (401) is provided with a cavity opening upwards, the cavity being connected to the water storage container (1) via a water inlet pipe (6); the top of the water guide box (401) is detachably connected to the middle frame (402); and the top of the middle frame (402) is detachably connected to the drainage box (403); The middle frame (402) is a hollow structure, the bottom of the middle frame (402) is fixedly connected to the bottom grid plate (404), a plurality of partition grid plates (405) are arranged inside the middle frame (402), the partition grid plates (405) are hollow cylindrical structures, the bottom of the partition grid plates (405) are fixedly connected to the bottom grid plate (404), the plurality of partition grid plates (405) are nested in layers and coaxially distributed, the outer diameters of the plurality of partition grid plates (405) increase from the inside to the outside, the plurality of partition grid plates (405) divide the interior of the middle frame (402) into a plurality of filling cavities, the filling cavities are filled with the porous matrix (406); the interior of the partition grid plate (405) located in the middle is not filled with the porous matrix (406) and forms the through crack (8); A plurality of drainage chambers are arranged in the drainage box (403), and the plurality of drainage chambers are connected to the filling cavity and the through crack (8) in a one-to-one correspondence.

3. The nonlinear seepage velocity equivalent test device for simulating fractured rock mass according to claim 2, characterized in that: A plurality of annular baffles (408) are fixedly connected inside the drainage box (403), and the plurality of annular baffles (408) divide the interior of the drainage box (403) into a plurality of drainage chambers of annular structures; drainage holes (409) corresponding to the plurality of drainage chambers are arranged at the bottom of the drainage box (403), and the drainage holes (409) connect the drainage chamber and the filling chamber; and drainage pipes (410) corresponding to the plurality of drainage chambers are fixedly arranged at the top of the drainage box (403).

4. The nonlinear seepage velocity equivalent test device for simulating fractured rock mass according to claim 2, characterized in that: It also comprises a grouting shaft (413), the partition grid plate (405) located in the middle is sleeved on the grouting shaft (413), and a gap is distributed between the inner wall surface of the partition grid plate (405) and the outer side surface of the grouting shaft (413), and the gap is used to fill part of the filling matrix (407) to form a partially filled through crack (8).

5. The nonlinear seepage velocity equivalent test device for simulating fractured rock mass according to claim 4, characterized in that: A first threaded hole is provided on the bottom grid plate (404), a second threaded hole is provided on the drainage box body (403), and the grouting shaft body (413) is threadedly connected to the first and second threaded holes; The grouting shaft (413) is provided with a blind hole opening upward, and the side wall of the grouting shaft (413) is provided with a waist-shaped hole (414) communicating with the blind hole; a drainage grouting pipe (411) is provided on the top of the drainage box (403), and a switch valve (412) is provided on the drainage grouting pipe (411); The drainage grouting pipe (411) is used to inject the partial filling matrix (407) into the gap on the outer side of the grouting shaft (413), and is used to form the blocked through crack (8) when the switch valve (412) is closed.

6. The nonlinear seepage velocity equivalent test device for simulating fractured rock mass according to claim 1, characterized in that: The pressure measuring part (3) comprises a pressure measuring tube (301), a stopper (302), a slider (304), a spring (306) and a piston (307); The pressure measuring tube (301) is arranged vertically, and its bottom is connected to the water storage container (1). The piston (307) is arranged in the pressure measuring tube (301). The piston (307) is a hollow structure. The slider (304) can slide through the inside of the piston (307). The top and bottom of the slider (304) are both T-shaped structures. The spring (306) is arranged below the T-shaped structure at the top of the slider (304). The spring (306) is sleeved on the slider (304). The T-shaped structure at the bottom of the slider (304) abuts against the bottom surface of the piston (307); The slider (304) is provided with a guide hole (305) opening upward, a through hole (308) communicating with the guide hole (305) is provided on the side of the slider (304), the inner wall surface of the piston (307) blocks the through hole (308), the stopper (302) is provided above the slider (304), and the stopper (302) is provided with a pressure relief hole (303) adapted to the guide hole (305); When the piston (307) rises until the slider (304) abuts against the stopper (302), the slider (304) moves downward, causing the through hole (308) to move downward away from the piston (307), thereby allowing the through hole (308), the flow guide hole (305) and the pressure relief hole (303) to communicate with the portion of the pressure measuring tube (301) located below the piston (307); The pressure measuring tube (301) is provided with scale lines for measuring pressure.

7. A nonlinear seepage velocity equivalent test method for simulating fractured rock mass, applied to the test device according to claim 1, characterized in that: The following steps are involved: Step 1: Arrange the test device, the water supply part (2), the water storage container (1), and the porous matrix part (4) are connected in sequence, the water storage container (1) is connected to the pressure measuring part (3), the porous matrix part (4) is filled with a porous matrix (406), and a through crack (8) is provided; Step 2: The water supply part (2) supplies water to the water storage container (1), and the water pressure of the water storage container (1) is observed by the pressure measuring part (3), and the water output of each drainage chamber is collected. The water volume of each drainage chamber is recorded as V 1. V 2. V 3…… V n , calculate the average flow velocity in the drainage chamber through the flow rate, and draw the flow velocity distribution curve; Step 3: After the test, take out the porous matrix and determine the porosity of the converted porous matrix according to the geotechnical test standard. n and water permeability K , which passed the test K and n The velocity distribution of the porous matrix is ​​calculated based on the values ​​and characteristic dimensions of the model.

8. The method for testing nonlinear seepage velocity of a rock mass containing through fractures according to claim 6, characterized in that: In step 1, the through crack (8) is blocked or partially filled. When partially filled, an axial body is placed in the through crack (8), and a gap is formed between the axial body and the inner wall of the through crack (8). A part of the filling matrix (407) is filled in the gap, and then the axial body is removed to form a partially filled through crack (8).

9. The method for testing nonlinear seepage velocity of a rock mass containing through fractures according to claim 7, characterized in that: In step 3, the porosity n and water permeability K Obtained by the following formula: ， Where: Q is the amount of water flowing through the porous matrix part; L is the length of the porous matrix; A is the cross-sectional area of ​​the porous matrix; is the hydraulic head difference at both ends of the porous matrix, in units of m ; t The test period; ， Where: V 0 is the volume of the porous matrix; the unit m 3 m2 is the mass of the pore matrix in water at saturated state; m1 is the mass of the porous matrix in the dry state.

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