Device and method for testing the crushable water storage properties

Abstract

The application provides a crushing and swelling water storage characteristic testing device and method, which comprises a testing body, the testing body is provided with a confining pressure cavity, a first communication port assembly, a second communication port assembly and a containing part, the confining pressure cavity is communicated with the first communication port assembly, so that the confining pressure cavity is vacuumized and water is injected through the first communication port assembly; the containing part is a flexible part, the containing part is provided with a containing cavity for containing a test piece, the containing cavity is communicated with the second communication port assembly, so that the containing cavity is vacuumized and water is injected through the second communication port assembly; the testing body further comprises a plurality of loading plates, each loading plate is movably arranged along the direction of approaching and moving away from the containing part, so that the loading plate is pressed on the containing part when the loading plate moves towards the containing part, and the crushing and swelling water storage characteristic testing device solves the problem that the crushing and swelling water storage characteristic testing device in the prior art cannot dynamically obtain the crushing and swelling coefficients and water storage coefficients of the overburden rock in the real caving process and the stress broken state.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coal mining, in particular, relates to a broken swelling water storage characteristic testing device and method. BACKGROUND

[0002] The coal mine underground reservoir water resource recycling technology system is proposed, which uses the goaf formed by coal mining as a space for water resource storage and purification, collects and stores the water resources damaged by mining in the underground goaf, and can realize effective protection and recycling of coal mining water resources. Among them, after the coal seam is mined, the overlying strata collapse and swell in volume, forming voids and cracks which are the main water storage space. Therefore, the index of volume swelling after the rock mass is broken (broken swelling coefficient) and the index of rock mass water storage capacity (water storage coefficient) are of great significance to the determination of the capacity of the underground reservoir.

[0003] For near-horizontal coal seams, the overlying rock mass of the goaf is in a "masonry beam" stress state, which breaks and swells under the action of compressive stress, shear stress and bending stress caused by vertical load. Its broken swelling characteristics and water storage characteristics mainly depend on the block size and arrangement and accumulation method of the rock mass, which are determined by factors such as rock properties, mining process parameters, and mine pressure. Under laboratory conditions, comprehensive consideration of the above factors and high reduction of the block size and accumulation method of the goaf rock mass can ensure the accuracy of the test data. For this reason, various testing devices and testing methods have appeared:

[0004] For example, a coal mine underground reservoir water storage coefficient measuring device is provided, which includes a test box containing similar simulation material rock mass, one side of which is connected to a water storage bin through a water delivery pipe, the other side is connected to a water storage amount monitoring device through a water outlet pipe, the top is placed with a pressurizing plate, and is connected to a pressurizing device through a pressurizing rod and a lever. The device can simulate the roof pressure environment of the water storage goaf and measure the water storage coefficient under the action of the roof pressure. However, the device uses rock mass similar material with great difference from the original rock pore and fracture structure (great difference in rock properties), does not consider the mining process parameters on site, and applies a uniform load to the roof stress environment, which seriously affects the accuracy and effectiveness of the test data.

[0005] For example, a broken swelling coefficient measuring device, method and water absorption rate measuring method are provided, which measuring device includes a first container and a second container in communication with each other, a pressurizing component, and a power component. Based on the principle of communicating vessels, the volume of complete rock blocks and rock fragments is measured to realize the measurement of the broken swelling coefficient and the water absorption rate. However, the device and method do not consider the mining process parameters and mine pressure on site, which seriously affects the accuracy and effectiveness of the test data.

[0006] For example, a coal rock residual crushing swelling coefficient measuring method and system are provided, step 1, measuring the original volume; step 2, placing the rock to be measured into a crushing cylinder; crushing the rock in the cylinder by a falling hammer until the crushing size of the rock to be measured meets the requirements; placing the rock fragments to be measured into a sample separation sieve for separation; step 3, placing the rock fragments to be measured into a pressure cylinder; applying stress pressure to the rock fragments to be measured by a separate hydraulic jack; calculating the volume after crushing; step 4, calculating the rock residual crushing swelling coefficient. However, the device and method do not consider the mining process parameters and mine pressure on site, which seriously affects the accuracy and effectiveness of the test data. SUMMARY

[0007] The main purpose of the present application is to provide a crushing and swelling water storage characteristic testing device and method to solve the problem that the crushing and swelling water storage characteristic testing device in the prior art cannot dynamically obtain the crushing and swelling coefficients and water storage coefficients of the overburden rock in the real caving process and the stress crushing state. In order to achieve the above purpose, according to one aspect of the present application, a crushing and swelling water storage characteristic testing device is provided, which comprises a test body, the test body has a confining pressure cavity, a first communication port assembly, a second communication port assembly and a containing part arranged in the confining pressure cavity, the confining pressure cavity is in communication with the first communication port assembly to vacuum and water injection in the confining pressure cavity through the first communication port assembly; the containing part is a flexible part, the containing part has a containing cavity for containing a test piece, the containing cavity is in communication with the second communication port assembly to vacuum and water injection in the containing cavity through the second communication port assembly; the test body further comprises: a plurality of loading plates, the plurality of loading plates are arranged in the confining pressure cavity and above the containing part, each loading plate is movably arranged in the direction of approaching and away from the containing part, so that the loading plate is pressed on the containing part when the loading plate moves towards the containing part, to load the test piece in the containing part.

[0008] Further, the test body comprises a plurality of first driving members, the plurality of first driving members are arranged one by one corresponding to the plurality of loading plates, a first output shaft of each first driving member is drivingly connected with the loading plate, so that the first driving member drives the loading plate to make reciprocating linear motion; the loading plate is rotationally connected with the first output shaft, so as to be in close contact with the containing part when the loading plate is pressed on the containing part; and / or, the loading plate comprises a first main plate and a first contact part arranged on the first main plate, the first contact part is a flexible part, so as to be in contact with the containing part when the loading plate is pressed on the containing part.

[0009] Further, the end of the first output shaft has a first connecting part, the first connecting part is spherical; the loading plate is provided with a mounting groove matched with the shape of the first connecting part, so that the first connecting part is rotatably arranged in the mounting groove.

[0010] Further, the fragmentation and swelling water storage property testing device further comprises a bearing assembly arranged in the confining pressure cavity and below the containing part to bear the test piece in the containing cavity; the bearing assembly comprises a plurality of bearing plates, each of which is movably arranged in a direction towards and away from the containing part.

[0011] Further, the plurality of loading plates are sequentially arranged along a first preset direction, and the plurality of bearing plates are sequentially arranged along the first preset direction; the plurality of loading plates and the plurality of bearing plates are arranged in one-to-one correspondence, and each loading plate is arranged opposite to the corresponding bearing plate.

[0012] Further, the testing body comprises a plurality of second driving members arranged in one-to-one correspondence with the plurality of bearing plates, and each second driving member is drivingly connected with the bearing plate through a second output shaft to drive the bearing plate to make a reciprocating linear motion; the bearing plate is rotatably connected with the second output shaft to be in close contact with the containing part when the bearing plate bears the containing part; and / or the bearing plate comprises a second main plate and a second contact part arranged on the second main plate, and the second contact part is a flexible member to be in contact with the containing part when the bearing plate supports the containing part.

[0013] Further, the testing body comprises a main body part, a first structure, a second structure, a first piston and a second piston, the main body part has a confining pressure cavity, and the containing part is connected with the main body part; the first structure is connected with the main body part, and the first structure has a first cavity in communication with the containing cavity, and the first piston is movably arranged in the first cavity and the containing cavity; the second structure is connected with the main body part, and the second structure and the first structure are located on opposite sides of the main body part; the second structure has a second cavity in communication with the containing cavity, and the second piston is movably arranged in the second cavity and the containing cavity to clamp the test piece in the containing cavity.

[0014] Further, the second communication port assembly comprises a third communication port for vacuumizing; the testing body further comprises a first piston rod, a first end of the first piston rod being connected with the first piston, a second end of the first piston rod being arranged outside the first structure through the first structure; the testing body has a first through hole, the first through hole sequentially penetrating the first piston rod and the first piston, one end of the first through hole at the second end of the first piston rod being the third communication port, the other end of the first through hole being in communication with the accommodating cavity between the first piston and the second piston; and / or, the second communication port assembly comprises a fourth communication port for water injection; the testing body further comprises a second piston rod, a first end of the second piston rod being connected with the second piston, a second end of the second piston rod being arranged outside the second structure through the second structure; the testing body has a second through hole, the second through hole sequentially penetrating the second piston rod and the second piston, one end of the second through hole at the second end of the second piston rod being the fourth communication port, the other end of the second through hole being in communication with the accommodating cavity between the first piston and the second piston; and / or, the first structure is provided with a first oil inlet, a first oil cavity being formed between the first piston and the first structure, the first oil cavity being in communication with the first oil inlet, so that the first piston moves linearly by adjusting the amount of oil entering the first oil cavity through the first oil inlet; and / or, the second structure is provided with a second oil inlet, a second oil cavity being formed between the second piston and the second structure, the second oil cavity being in communication with the second oil inlet, so that the second piston moves linearly by adjusting the amount of oil entering the second oil cavity through the second oil inlet; and / or, the testing body further comprises a first sealing member, the first sealing member being connected with the accommodating portion and arranged around the accommodating portion, the first sealing member being clamped between the main body portion and the first structure; and / or, the testing body further comprises a second sealing member, the second sealing member being connected with the accommodating portion and arranged around the accommodating portion, the second sealing member being clamped between the main body portion and the second structure.

[0015] Further, the first communication port assembly comprises a first communication port, the crush resistance water storage characteristic testing device further comprises a first vacuum pump, the first vacuum pump being in communication with the first communication port; and / or, the first communication port assembly comprises a second communication port, the crush resistance water storage characteristic testing device further comprises a first constant-speed constant-pressure pump, the first constant-speed constant-pressure pump being in communication with the second communication port, so that the first constant-speed constant-pressure pump injects water into the confining pressure cavity through the second communication port; and / or, the second communication port assembly comprises a third communication port, the crush resistance water storage characteristic testing device further comprises a second vacuum pump, the second vacuum pump being in communication with the third communication port; and / or, the second communication port assembly comprises a fourth communication port, the crush resistance water storage characteristic testing device further comprises a second constant-speed constant-pressure pump, the second constant-speed constant-pressure pump being in communication with the fourth communication port, so that the second constant-speed constant-pressure pump injects water into the accommodating cavity through the fourth communication port.

[0016] According to another aspect of the present invention, a method for testing the water storage characteristics of fractured and bulging strata is provided, applicable to the aforementioned test apparatus for testing water storage characteristics of fractured and bulging strata. The method for testing water storage characteristics of fractured and bulging strata includes: step S110, based on the thickness and length of the overlying strata in the goaf, the width of the coal pillar, the height of the goaf, and the pressure of the overlying strata, according to the similarity criterion C τ =C σ C l / C h =1,C σ =1, and C M =C σ (C l / C h ) 2 =1. Determine the specimen length l and thickness h, the simulated coal pillar width x, the simulated goaf height y, and the applied load of the loading plate; where, C τ For the shear stress similarity scale, C σ For the compressive stress similarity scale, C M For the bending stress similarity scale, C l and C h The length and thickness of the overlying strata are similar to the scale. In step S120, the number of annular structures *n* is adjusted according to the determined specimen length *l*, so that the total length *l'* of the *n* annular structures equals the specimen length *l*. An additional annular structure is added to each side of the *n* annular structures to simulate the coal pillar support effect. At this point, the total number of annular structures is *n+2*. The loading plate and bearing plate are each annular structure. In step S130, a core is taken from the field and processed into a specimen with a length of *l'+2x* and a thickness of *h*. The initial apparent volume *V0* of the specimen is obtained using the drainage method. The length of the annular structure on each side of the *n* annular structures is equal to the simulated width *x* of the coal pillar. In step S140, the loading plate and bearing plate are adjusted to be horizontal, and the specimen processed in step S130 is inserted. The specimen is then adjusted to the middle position and clamped using the first and second pistons. At this point, the specimen and the *n* annular structures... The contact length of the bearing plates on the left and right sides of the shaped structure is the simulated width x of the coal pillar; in step S150, the first vacuum pump and the second vacuum pump are used to evacuate the confining pressure cavity and the receiving cavity respectively; in step S160, the first constant speed and constant pressure pump is used to inject water at a constant pressure into the confining pressure cavity, and the change in water volume ΔV1 in the confining pressure cavity is monitored in real time; then, the second constant speed and constant pressure pump is used to inject water at a pressure lower than that in the confining pressure cavity into the receiving cavity, and the change in the injected water volume V2 is monitored in real time; in step S170, pressure is applied to the specimen according to the applied load of the loading plate determined in step S110; in step S180, using the initial apparent volume V0 of the specimen obtained in step S130 and the change in water volume ΔV1 in the confining pressure cavity and the real-time injected water volume V2 in the receiving cavity obtained in step S160, the dynamic water storage characteristics of the specimen are obtained by the formula V2 / V0, and the dynamic fragmentation characteristics of the specimen are obtained by the formula (ΔV1+V0) / V0.

[0017] The technical scheme of the present application is applied to the broken and dilated water storage characteristic testing device, which comprises a testing body, the testing body has a confining pressure cavity, a first communication port assembly, a second communication port assembly and a containing part arranged in the confining pressure cavity, the containing part is a flexible part, and the containing part has a containing cavity for containing a test piece. When testing the broken and dilated water storage characteristic of the test piece, the confining pressure cavity is first vacuumized through the first communication port assembly, and the containing cavity is vacuumized through the second communication port assembly; then the confining pressure cavity is water-injected through the first communication port assembly, the containing cavity is water-injected through the second communication port assembly, and the water amount changes in the confining pressure cavity and the containing cavity are observed; finally, the plurality of loading plates are controlled to move towards the containing part, so that the plurality of loading plates are arranged on the containing part, the test piece in the containing part is loaded, the compression stress suffered by the test piece is simulated, wherein each loading plate can be independently driven, the displacement of each loading plate can be not completely same, and the force acting on the containing part can be not completely same, the shear stress and the bending stress suffered by the test piece are simulated, the loading of the test piece by the plurality of loading plates can simulate the real stress state of the overburden strata of the goaf, so as to ensure the accuracy of the test data, thereby improving the test data accuracy of the broken and dilated water storage characteristic testing device of the present application, and solving the problem that the broken and dilated water storage characteristic testing device in the prior art cannot simulate the caving process and the stress and broken state of the overburden strata of the goaf. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the present application, and together with the description of the exemplary embodiments of the present application, serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0019] Figure 1 A schematic view of an embodiment of the broken and dilated water storage characteristic testing device according to the present application is shown;

[0020] Figure 2 A schematic view of a first structure of the broken and dilated water storage characteristic testing device according to the present application is shown;

[0021] Figure 3 A schematic view of direct roof rock water storage coefficient testing of the broken and dilated water storage characteristic testing device according to the present application is shown;

[0022] Figure 4 A schematic view of non-direct roof rock water storage coefficient testing of the broken and dilated water storage characteristic testing device according to the present application is shown.

[0023] In the above drawings, the following reference signs are included:

[0024] 1, test body; 10, first piston rod; 102, first through hole; 103, fourth communication port; 104, second piston rod; 106, second through hole; 107, first sealing element; 108, second sealing element; 109, first communication port; 110, second communication port; 11, confining pressure cavity; 111, third communication port; 12, containing portion; 121, containing cavity; 13, loading plate; 14, first driving element; 141, first output shaft; 142, first connecting portion; 15, second driving element; 151, second output shaft; 152, second connecting portion; 16, main body portion; 17, first structure; 171, first cavity; 172, first oil inlet; 18, second structure; 181, second cavity; 182, second oil inlet; 19, first piston; 191, first oil cavity; 192, second oil cavity; 193, second piston; 20, test piece; 30, bearing assembly; 31, bearing plate; 40, first vacuum pump; 50, first constant-speed constant-pressure pump; 60, second vacuum pump; 70, second constant-speed constant-pressure pump. DETAILED DESCRIPTION

[0025] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0027] It should be noted that the terms used herein are only for the purpose of describing the specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, they indicate the presence of a feature, step, operation, device, component and / or combination thereof.

[0028] The present application provides a fragmentation and swelling water storage property testing device, please refer to Figures 1 to 4, including a test body 1, the test body 1 having a confining pressure cavity 11, a first communicating port assembly, a second communicating port assembly and a containing part 12 arranged in the confining pressure cavity 11, the confining pressure cavity 11 being communicated with the first communicating port assembly to vacuumize and inject water into the confining pressure cavity 11 through the first communicating port assembly; the containing part 12 being a flexible part, the containing part 12 having a containing cavity 121 for containing a test piece 20, the containing cavity 121 being communicated with the second communicating port assembly to vacuumize and inject water into the containing cavity 121 through the second communicating port assembly; the test body 1 further comprising: a plurality of loading plates 13, the plurality of loading plates 13 being arranged in the confining pressure cavity 11 and above the containing part 12, each loading plate 13 being movably arranged in a direction towards the containing part 12, so as to be pressed on the containing part 12 when the loading plate 13 moves towards the containing part 12, to load the test piece 20 in the containing part 12.

[0029] The broken and expanded water storage characteristic testing device can simulate the caving process and the stress broken state of the overburden strata of the goaf, and comprises a test body 1, the test body 1 having a confining pressure cavity 11, a first communicating port assembly, a second communicating port assembly and a containing part 12 arranged in the confining pressure cavity 11, the containing part 12 being a flexible part, the containing part 12 having a containing cavity 121 for containing a test piece 20. When testing the broken and expanded water storage characteristic of the test piece 20, the confining pressure cavity 11 is first vacuumized through the first communicating port assembly, and the containing cavity 121 is vacuumized through the second communicating port assembly; then the confining pressure cavity 11 is injected with water through the first communicating port assembly, the containing cavity 121 is injected with water through the second communicating port assembly, and the water quantity change in the confining pressure cavity 11 and the containing cavity 121 is observed; finally, the plurality of loading plates 13 are controlled to move towards the containing part 12, so that the plurality of loading plates 13 are pressed on the containing part 12, to load the test piece 20 in the containing part 12, to simulate the compressive stress, the shear stress and the bending stress suffered by the test piece 20, wherein each loading plate 13 can be independently driven, the displacement of each loading plate 13 can not be completely same, and the force acting on the containing part 12 can not be completely same, to simulate the shear stress and the bending stress suffered by the test piece 20, so that the loading of the test piece 20 by the plurality of loading plates 13 can simulate the real stress state of the overburden strata of the goaf, to ensure the accuracy of the test data, to improve the test data accuracy of the broken and expanded water storage characteristic testing device, and to solve the problem that the broken and expanded water storage characteristic testing device in the prior art cannot dynamically obtain the broken and expanded coefficients and the water storage coefficients of the overburden strata of the goaf in the real caving process and the stress broken state.

[0030] Specifically, the containing part 12 is a flexible part, the flexible part deforms under stress and restores after the stress disappears. The containing part 12 is made of rubber.

[0031] Optionally, the test piece 20 is a plate-shaped original rock test piece obtained by geometric scaling according to the size of the overburden rock stratum of the goaf on site, and the width and height are fixed, for example, width:height = 6 cm:4 cm, and the length is obtained by multiplying the length of the rock stratum goaf or the rock stratum caving step distance by the geometric scaling factor.

[0032] In the embodiment, the test body 1 comprises a plurality of first driving members 14, the plurality of first driving members 14 are arranged in one-to-one correspondence with the plurality of loading plates 13, the first output shaft 141 of each first driving member 14 is drivingly connected with the loading plate 13, so that the first driving member 14 drives the loading plate 13 to move reciprocatingly and linearly; the loading plate 13 is rotationally connected with the first output shaft 141, so as to be in close contact with the accommodating portion 12 when the loading plate 13 is pressed on the accommodating portion 12; and / or the loading plate 13 comprises a first main plate and a first contact portion arranged on the first main plate, the first contact portion is a flexible member, so as to be in contact with the accommodating portion 12 when the loading plate 13 is pressed on the accommodating portion 12.

[0033] Specifically, each first driving member 14 drives each loading plate 13 to move reciprocatingly and linearly in a direction towards close to and away from the accommodating portion 12, so that each loading plate 13 can be pressed on the accommodating portion 12 or away from the accommodating portion 12, thereby loading or stopping loading the test piece 20 in the accommodating portion 12. The plurality of first driving members 14 are arranged in one-to-one correspondence with the plurality of loading plates 13, so that the first driving member 14 can drive the corresponding loading plate 13 to move differently, and the force acting on the accommodating portion 12 can also not be completely the same, thereby simulating the compressive stress, shear stress and bending stress that the test piece 20 is subjected to, so that the loading of the test piece 20 by the plurality of loading plates 13 can truly simulate the real stress state of the overburden rock stratum of the goaf, further ensuring the accuracy of the test data.

[0034] Optionally, the first driving member is a loading oil cylinder.

[0035] In the embodiment, the loading plate 13 is rotationally connected with the first output shaft 141, so as to be in close contact with the accommodating portion 12 when the loading plate 13 is pressed on the accommodating portion 12. Such a configuration allows the angle of the loading plate 13 to be freely adjusted, and the loading plate 13 can be completely pressed on the accommodating portion 12, thereby simulating the compressive stress, shear stress and bending stress that the test piece 20 is subjected to, so that the loading of the test piece 20 by the plurality of loading plates 13 can truly simulate the real stress state of the overburden rock stratum of the goaf, further ensuring the accuracy of the test data.

[0036] In the embodiment, the loading plate 13 comprises a first main plate and a first contact portion arranged on the first main plate, the first contact portion is a flexible member, so as to be in contact with the accommodating portion 12 when the loading plate 13 is pressed on the accommodating portion 12.

[0037] Specifically, the flexible piece is deformed under force and returns to its original shape after the force disappears. The first contact part is made of rubber. In actual implementation, the first contact part is flexible, so that the first contact part can bend along with the bending of the containing part 12, thereby ensuring that the loading plate 13 is always in contact with the containing part 12 when the loading plate 13 is pressed on the containing part 12, so that the loading plate 13 uniformly loads the test piece 20, and the real stress state of the overburden strata of the goaf can be truly simulated, further ensuring the accuracy of the test data.

[0038] In this embodiment, the end of the first output shaft 141 has a first connecting part 142 in the shape of a ball; the loading plate 13 is provided with a mounting groove matching the shape of the first connecting part 142, so that the first connecting part 142 is rotatably arranged in the mounting groove.

[0039] Specifically, the ball-shaped first connecting part 142 is rotatably arranged in the mounting groove, so that the angle of the loading plate 13 can be freely adjusted, thereby simulating the pressure shear stress and bending stress to which the test piece 20 is subjected, so that the real stress state of the overburden strata of the goaf can be truly simulated by loading the test piece 20 with multiple loading plates 13, further ensuring the accuracy of the test data.

[0040] Optionally, the first main plate is made of a rigid material, and the first contact part is made of rubber, so that the test piece 20 with slight unevenness can be uniformly loaded.

[0041] In this embodiment, the device for testing the crushing and swelling water storage characteristics further comprises a bearing assembly 30 arranged in the confining pressure cavity 11 and below the containing part 12 to bear the test piece 20 in the containing cavity 121; the bearing assembly 30 comprises a plurality of bearing plates 31, each of which is movably arranged in the direction of approaching and moving away from the containing part 12.

[0042] Specifically, the bearing assembly 30 is used to bear the test piece 20 in the containing cavity 121, and the height of the support for the test piece 20 is changed by moving each bearing plate 31 in the direction of approaching and moving away from the containing part 12, thereby truly simulating the height change of the goaf, thereby further ensuring the accuracy of the test data.

[0043] In this embodiment, the plurality of loading plates 13 are arranged in sequence along a first preset direction, and the plurality of bearing plates 31 are arranged in sequence along the first preset direction; the plurality of loading plates 13 and the plurality of bearing plates 31 are arranged one-to-one, and each loading plate 13 is arranged opposite to the corresponding bearing plate 31.

[0044] Specifically, the first preset direction is, for example, the horizontal direction. Figure 1The loading plates 13 are arranged opposite to the corresponding bearing plates 31, so that when the loading plates 13 load the test piece 20 in the accommodating cavity 121 at a certain position, the corresponding bearing plates 31 can bear the reaction force of the test piece 20 at the position, so as to avoid that the bearing plates 31 and the loading plates 13 have too large load difference on the test piece 20, and damage the accommodating part 12 and the test piece 20.

[0045] In the embodiment, the test body 1 includes a plurality of second driving members 15, the plurality of second driving members 15 are arranged in one-to-one correspondence with the plurality of bearing plates 31, the second output shaft 151 of each second driving member 15 is drivingly connected with the bearing plate 31, so that the second driving member 15 drives the bearing plate 31 to move in a reciprocating straight line; the bearing plate 31 is rotationally connected with the second output shaft 151, so as to be in close contact with the accommodating part 12 when the bearing plate 31 bears the accommodating part 12; and / or the bearing plate 31 includes a second main plate and a second contact part arranged on the second main plate, the second contact part is a flexible member, so as to be in contact with the accommodating part 12 when the bearing plate 31 supports the accommodating part 12.

[0046] Specifically, the second driving member 15 drives the bearing plate 31 to move in a reciprocating straight line along a direction towards the accommodating part 12 or away from the accommodating part 12, so that the bearing plate 31 drives the accommodating part 12 and the test piece 20 to move upwards or downwards, thereby changing the height of the test piece 20. The plurality of second driving members 15 are arranged in one-to-one correspondence with the plurality of bearing plates 31, so that each second driving member 15 can drive each bearing plate 31 to complete different displacements, so that different positions of the test piece 20 are at different heights, thereby truly simulating the height change of the goaf, thereby further ensuring the accuracy of the test data.

[0047] Specifically, the flexible member deforms under stress and restores after the stress disappears. The second contact part is made of rubber.

[0048] In specific implementation, for the direct roof rock, the flexible bearing plate 31 can be gradually lowered to simulate the coal seam mining, as shown in Figure 3 For the non-direct roof rock, the flexible bearing plate 31 can be gradually lowered to simulate the sinking curve of the rock bottom interface, as shown in Figure 4 .

[0049] Optionally, the second driving member is an oil cylinder.

[0050] In the embodiment, the bearing plate 31 is rotationally connected with the second output shaft 151, so as to be in close contact with the accommodating part 12 when the bearing plate 31 bears the accommodating part 12.

[0051] Specifically, the end of the second output shaft 151 has a second connecting part 152 in a spherical shape; the bearing plate 31 is provided with a mounting groove matched with the shape of the second connecting part 152, so that the second connecting part 152 is rotatably arranged in the mounting groove, so that the angle of the bearing plate 31 can be adjusted, thereby ensuring that the bearing plate 31 is in close contact with the containing part 12 when bearing the containing part 12, so that the bearing plate 31 can completely bear the containing part 12, thereby ensuring that the bearing plate 31 can bear the test piece 20 according to the set pressure, avoiding that the bearing plate 31 cannot bear the test piece 20 in reaction force, resulting in damage to the containing part 12 and the test piece 20.

[0052] In the embodiment, the test body 1 includes a main body part 16, a first structure 17, a second structure 18, a first piston 19 and a second piston 193, the main body part 16 has a confining pressure cavity 11, and the containing part 12 is connected with the main body part 16; the first structure 17 is connected with the main body part 16, and the first structure 17 has a first cavity 171, which is in communication with the containing cavity 121, and the first piston 19 is movably arranged in the first cavity 171 and the containing cavity 121; the second structure 18 is connected with the main body part 16, and the second structure 18 and the first structure 17 are located on opposite sides of the main body part 16; the second structure 18 has a second cavity 181, which is in communication with the containing cavity 121, and the second piston 193 is movably arranged in the second cavity 181 and the containing cavity 121, so that the first piston 19 and the second piston 193 clamp the test piece 20 located in the containing cavity 121.

[0053] Specifically, the projection of the first piston 19 and the second piston 193 perpendicular to the first preset direction is consistent with the size of the projection of the test piece 20 perpendicular to the first preset direction, the first piston 19 moves in the first cavity 171 and the containing cavity 121 in the direction towards or away from the test piece 20, and the second piston 193 moves in the second cavity 181 and the containing cavity 121 in the direction towards or away from the test piece 20, which can realize the adjustment of the end size of the test piece 20, so as to simulate the change of the coal pillar width on the left and right sides of the goaf rock mass, so that the first piston 19 and the second piston 193 can respectively fix the end of the test piece 20 from the left and right ends of the test piece 20, avoid the test piece 20 moving along the first preset direction, simulate the end fixing of the coal pillar on the left and right sides of the goaf rock mass to the rock mass, and further ensure the accuracy of the test data.

[0054] In specific implementation, the first structure 17 and / or the second structure 18 are detachably connected with the main body part 16, so as to facilitate the test piece 20 to be placed in the containing cavity 121.

[0055] Optionally, the first structure 17 and the second structure 18 are end-fixed oil cylinders; a sealing ring is arranged between the first piston 19 and the first structure 17 to ensure normal operation of the oil cylinder and airtightness of the space; a sealing ring is arranged between the second structure 18 and the second piston 193 to ensure normal operation of the oil cylinder and airtightness of the space.

[0056] In the embodiment, the second communication port assembly includes a third communication port 111 for vacuumizing; the test body 1 further includes a first piston rod 10, a first end of the first piston rod 10 being connected with the first piston, a second end of the first piston rod 10 being arranged outside the first structure 17 through the first structure 17; the test body 1 has a first through hole 102, the first through hole 102 sequentially penetrating the first piston rod 10 and the first piston 19, one end of the first through hole 102 at the second end of the first piston rod 10 being the third communication port 111, the other end of the first through hole 102 being in communication with the accommodating cavity 121 between the first piston 19 and the second piston 193; and / or, the second communication port assembly includes a fourth communication port 103 for water injection; the test body 1 further includes a second piston rod 104, a first end of the second piston rod 104 being connected with the second piston, a second end of the second piston rod 104 being arranged outside the second structure 18 through the second structure 18; the test body 1 has a second through hole 106, the second through hole 106 sequentially penetrating the second piston rod 104 and the second piston 193, one end of the second through hole 106 at the second end of the second piston rod 104 being the fourth communication port 103, the other end of the second through hole 106 being in communication with the accommodating cavity 121 between the first piston 19 and the second piston 193; and / or, the first structure 17 is provided with a first oil inlet 172, a first oil cavity 191 being surrounded between the first piston 19 and the first structure 17, the first oil cavity 191 being in communication with the first oil inlet 172, so that the first piston 19 moves in a reciprocating linear manner by adjusting the amount of oil entering the first oil cavity 191 through the first oil inlet 172; and / or, the second structure 18 is provided with a second oil inlet 182, a second oil cavity 192 being surrounded between the second piston 193 and the second structure 18, the second oil cavity 192 being in communication with the second oil inlet 182, so that the second piston 193 moves in a reciprocating linear manner by adjusting the amount of oil entering the second oil cavity 192 through the second oil inlet 182; and / or,

[0057] The test body 1 further includes a first sealing member 107, the first sealing member 107 being connected with the accommodating portion 12 and arranged around the accommodating portion 12, the first sealing member 107 being clamped between the main body portion 16 and the first structure 17; and / or,

[0058] The test body 1 further includes a second sealing member 108, the second sealing member 108 being connected with the accommodating portion 12 and arranged around the accommodating portion 12, the second sealing member 108 being clamped between the main body portion 16 and the second structure 18.

[0059] Specifically, the first piston rod 10 can realize the isolation between the first through hole 102 and the first oil cavity 191, and the second piston rod 104 can realize the isolation between the second through hole 106 and the second oil cavity 192. The fluid, gas or water transmission channel can be provided for the test piece 20 from the end while the two pistons are pressing the test piece 20. The first through hole 102 is located at one end of the second end of the first piston rod 10, and the other end of the first through hole 102 is connected with the containing cavity 121 between the first piston 19 and the second piston 193. The gas in the containing cavity 121 can be extracted through the first through hole 102 and the third communication port 111, so that the test piece 20 is in a vacuum state. The second through hole 106 is located at one end of the second end of the second piston rod 104, and the other end of the second through hole 106 is connected with the containing cavity 121 between the first piston 19 and the second piston 193. Water can be injected into the containing cavity 121 through the fourth communication port 103 and the second through hole 106.

[0060] In specific implementation, the amount of oil entering the first oil cavity 191 from the first oil inlet 172 is adjusted to adjust the movement amount of the first piston 19 in the first cavity 171 and the containing cavity 121, so as to adjust the left end size of the test piece 20. The amount of oil entering the second oil cavity 192 from the second oil inlet 182 is adjusted to adjust the movement amount of the second piston 193 in the second cavity 181 and the containing cavity 121, so as to adjust the right end size of the test piece 20.

[0061] Optionally, a sealing member is arranged between the first structure 17 and the first piston rod 10, and a sealing member is arranged between the second structure 18 and the second piston rod 104, so as to ensure the normal operation of the oil cylinder and the airtightness of the space.

[0062] In the embodiment, the test body 1 further comprises: a first sealing member 107 connected with the containing part 12 and arranged around the containing part 12, the first sealing member 107 being clamped between the main body part 16 and the first structure 17; and / or a second sealing member 108 connected with the containing part 12 and arranged around the containing part 12, the second sealing member 108 being clamped between the main body part 16 and the second structure 18. Such arrangement can realize the sealing of the containing cavity 121 by the first sealing member 107 between the main body part 16 and the first structure 17 and the second sealing member 108 between the main body part 16 and the second structure 18, so as to avoid the failure of vacuumizing the containing cavity 121 or water leakage.

[0063] Optionally, the first sealing member 107 and the second sealing member 108 are rubber sealing rings.

[0064] In the embodiment, the first communication port assembly includes the first communication port 109, and the fragmentation and swelling water storage characteristic testing device further includes a first vacuum pump 40 connected with the first communication port 109; and / or, the first communication port assembly includes the second communication port 110, and the fragmentation and swelling water storage characteristic testing device further includes a first constant-speed constant-pressure pump 50 connected with the second communication port 110, so that the first constant-speed constant-pressure pump 50 injects water into the confining pressure cavity 11 through the second communication port 110; and / or, the second communication port assembly includes the third communication port 111, and the fragmentation and swelling water storage characteristic testing device further includes a second vacuum pump 60 connected with the third communication port 111; and / or, the second communication port assembly includes the fourth communication port 103, and the fragmentation and swelling water storage characteristic testing device further includes a second constant-speed constant-pressure pump 70 connected with the fourth communication port 103, so that the second constant-speed constant-pressure pump 70 injects water into the containing cavity 121 through the fourth communication port 103.

[0065] Specifically, the first vacuum pump 40 evacuates the confining pressure cavity 11 through the first communication port 109, and the second vacuum pump 60 evacuates the containing cavity 121 through the third communication port 111; the first constant-speed constant-pressure pump 50 injects water into the confining pressure cavity 11 through the second communication port 110, and the second constant-speed constant-pressure pump 70 injects water into the containing cavity 121 through the fourth communication port 103.

[0066] Specifically, the first constant-speed constant-pressure pump 50 and the second constant-speed constant-pressure pump 70 have a constant-pressure and constant-flow dual operation mode, and can record the operation state pressure, flow and other parameters of the pump in real time and high precision, provide a constant water pressure for the test piece 20, and test the change of the injected water volume in real time.

[0067] In specific implementation, the single first driving member 14 and the single loading plate 13, and the single second driving member 15 and the single bearing plate 31 can form a single ring structure, and the multiple ring structures are combined with the first structure body 17 and the second structure body 18, so as to form a sealed containing cavity and a confining pressure cavity. At the same time, by adjusting the number of ring structures, tests on test pieces 20 with different lengths can be carried out.

[0068] The application further provides a fragmentation and swelling water storage characteristic testing method, which is suitable for the fragmentation and swelling water storage characteristic testing device in the above embodiment, and includes the following steps.

[0069] In step S110, according to the thickness and length of the overlying strata of the goaf, the width of the coal pillar, the height of the goaf and the pressure of the overlying strata, the similarity criterion C τ =C σ C l / C h =1, C σ =1 and C M =Cσ (C l / C h ) 2 =1determine the length l and thickness h of the test piece 20, the coal pillar simulation width x, the applied load of the loading plate 13, to ensure that the test piece 20 is subjected to similar compressive stress, shear stress and bending stress as in the field; wherein, C τ is the shear stress similarity ratio, C σ is the compressive stress similarity ratio, C M is the bending stress similarity ratio, C l and C h are the overburden length and thickness similarity ratios, respectively. Among them, the length l and thickness h of the test piece 20 correspond to the length and thickness of the overburden, the coal pillar simulation width x corresponds to the coal pillar width, the goaf simulation height corresponds to the goaf height, and the applied load of the loading plate 13 simulates the overburden pressure.

[0070] Step S120, adjust the number of ring structures n according to the determined length l of the test piece 20, so that the total length l' of n ring structures is equal to the length l of the test piece 20, and one ring structure is added on both sides of the n ring structures for coal pillar support simulation, at this time the total number of ring structures is n+2; wherein, the loading plate 13 and the bearing plate 31 correspond to one ring structure.

[0071] Step S130, take the core from the field and process it into a test piece 20 with a length of l'+2x and a thickness of h, and obtain the initial apparent volume V0 of the test piece 20 by the drainage method; wherein, the length of one ring structure on both sides of the n ring structures is equal to the coal pillar simulation width x.

[0072] Step S140, adjust the loading plate 13 and the bearing plate 31 to be horizontal, load the test piece 20 processed in step S130, and adjust the test piece 20 to the middle position and clamp it by the first piston 19 and the second piston 193, at this time the contact length of the test piece 20 with the bearing plate 31 on both sides of the n ring structures is the coal pillar simulation width x.

[0073] Step S150, use the first vacuum pump 40 and the second vacuum pump 60 to respectively vacuum the confining pressure cavity 11 and the containing cavity 121.

[0074] Step S160, use the first constant-speed constant-pressure pump 50 to inject water with a constant pressure into the confining pressure cavity 11, and monitor the change AV1 of the water volume in the confining pressure cavity 11 in real time; then use the second constant-speed constant-pressure pump 70 to inject water with a pressure less than that of the confining pressure cavity 11 into the containing cavity 121, and monitor the change of the injected water volume V2 in real time.

[0075] Step S170, the applied load of the loading plate 13 determined in step S110 is applied to the test piece 20. For direct roof rock, the coal seam mining can be simulated by gradually lowering the loading plate 13, such as Figure 3 As shown, the lowering amount of the bearing plate 31 is fixed as the simulated height y of the goaf. For non-direct roof rock, the sinking profile curve of the rock bottom interface can be simulated by gradually lowering the bearing plate 31, such as Figure 4 As shown.

[0076] Step S180, the initial apparent volume V0 of the test piece 20 obtained in step S130 and the water volume change AV1 in the confining pressure cavity 11 and the real-time injected water volume V2 in the containing cavity 121 obtained in step S160 are used to obtain the dynamic water storage characteristics of the test piece 20 through the following formula V2 / V0, and the dynamic swelling characteristics of the test piece 20 are obtained through the formula (AV1+V0) / V0.

[0077] Specifically, the swelling and water storage characteristic testing device of the present application is used to test the swelling and water storage characteristics, which solves the problem that the swelling and water storage characteristic testing device in the prior art cannot truly simulate the caving process and stress broken state of the overlying rock of the goaf, and cannot dynamically and synchronously obtain the swelling coefficient and water storage coefficient of the caving rock in the above process.

[0078] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0079] The swelling and water storage characteristic testing device of the present application can truly simulate the caving process and stress broken state of the overlying rock of the goaf; it can truly simulate the real stress state (compressive stress, shear stress and bending stress) of the overlying rock of the goaf; it can freely adjust the core mining process parameters such as the height of the goaf and the width of the coal pillar which affect the swelling and water storage characteristics of the caving rock mass of the goaf; it can synchronously and dynamically obtain the water storage coefficient and the swelling coefficient of the caving rock mass of the goaf in the mining and compaction process.

[0080] The broken swelling water storage characteristic testing device of the application comprises a testing body 1, the testing body 1 has a confining pressure cavity 11, a first communication port assembly, a second communication port assembly and a containing part 12 arranged in the confining pressure cavity 11, the containing part 12 is a flexible part, the containing part 12 has a containing cavity 121 for containing a test piece 20. When testing the broken swelling water storage characteristic of the test piece 20, first, the confining pressure cavity 11 is vacuumized through the first communication port assembly, and the containing cavity 121 is vacuumized through the second communication port assembly; then, the confining pressure cavity 11 is water-filled through the first communication port assembly, the containing cavity 121 is water-filled through the second communication port assembly, and the water amount change in the confining pressure cavity 11 and the containing cavity 121 is observed; finally, a plurality of loading plates 13 are controlled to move towards the containing part 12, so that the plurality of loading plates 13 are arranged on the containing part 12, the test piece 20 in the containing part 12 is loaded, and the compressive stress suffered by the test piece 20 is simulated, wherein each loading plate 13 can be independently driven, the displacement of each loading plate 13 can not be completely same, and the force acting on the containing part 12 can not be completely same, the shear stress and the bending stress suffered by the test piece 20 are simulated, so that the loading of the test piece 20 by the plurality of loading plates 13 can simulate the compressive stress, the shear stress and the bending stress of the overburden strata of the goaf in the real stress state, thereby ensuring the accuracy of the test data, thereby improving the test data accuracy of the broken swelling water storage characteristic testing device of the application, and thereby solving the problem that the broken swelling water storage characteristic testing device in the prior art cannot dynamically obtain the broken swelling coefficient and the water storage coefficient of the overburden strata of the goaf in the real caving process and the stress broken state.

[0081] It should be noted that the terms "first", "second", and the like in the specification and claims of the application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to the clearly listed steps or units, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0082] For purposes of the description hereinafter, the terms "upper", "lower", "right", "left", "rear", "front", "vertical" and "horizontal" as can be perceived herein relative to the accompanying drawings refer to the orientation of the components being described. Unless specifically set forth herein, the terms "on", "onto", "attached", "connected" or "coupled" to, among others, and the like, are used to describe their intended orientation, and are subject to routine modification when the objects or components are turned over, rotated 90 degrees, or otherwise repositioned in other orientations.

[0083] The preferred embodiments herein disclosed are not to be construed as limiting, as the same is subject to modification and variation. Such variations are considered within the scope of the present application. The application is to be construed in accordance with the provisions of the patent laws and to support a fair but substantial interpretation.

Claims

1. A fragmentation and swelling water storage property testing device characterized by, The test body (1) comprises a confining pressure cavity (11), a first communication port assembly, a second communication port assembly, and a containing part (12) arranged in the confining pressure cavity (11), the confining pressure cavity (11) is communicated with the first communication port assembly to vacuumize and water-fill the confining pressure cavity (11) through the first communication port assembly; the containing part (12) is a flexible part, the containing part (12) has a containing cavity (121) for containing a test piece (20), the containing cavity (121) is communicated with the second communication port assembly to vacuumize and water-fill the containing cavity (121) through the second communication port assembly; the test body (1) further comprises: a plurality of loading plates (13), each of the plurality of loading plates (13) is arranged in the confining pressure cavity (11) and above the containing part (12), each of the loading plates (13) is movably arranged along a direction towards the containing part (12) and away from the containing part (12) respectively, so as to be pressed on the containing part (12) when the loading plate (13) moves towards the containing part (12), to load the test piece (20) in the containing part (12); the test body (1) comprises a first driving part (14), a first output shaft (141) of the first driving part (14) is rotationally connected with the loading plate (13), so as to be fitted with the containing part (12) when the loading plate (13) is pressed on the containing part (12); an end of the first output shaft (141) has a first connecting part (142), the first connecting part (142) is spherical; the loading plate (13) is provided with a mounting groove matched with the shape of the first connecting part (142), so that the first connecting part (142) is rotationally arranged in the mounting groove.

2. The test device according to claim 1, wherein the test body (1) comprises a plurality of first driving parts (14), each of the plurality of first driving parts (14) is arranged corresponding to one of the plurality of loading plates (13), a first output shaft (141) of each of the first driving parts (14) is drivingly connected with the loading plate (13), so that the first driving part (14) drives the loading plate (13) to make reciprocating linear motion; and / or the loading plate (13) comprises a first main plate and a first contact part arranged on the first main plate, the first contact part is a flexible part, so that the first contact part is in contact with the containing part (12) when the loading plate (13) is pressed on the containing part (12).

3. The burst storage property testing device according to claim 1 or 2, characterized by, The test device further comprises: a bearing assembly (30) arranged in the confining pressure cavity (11) and below the containing part (12), to bear the test piece (20) in the containing cavity (121); the bearing assembly (30) comprises a plurality of bearing plates (31), each of the bearing plates (31) is movably arranged along a direction towards the containing part (12) and away from the containing part (12) respectively.

4. The burst storage property testing device according to claim 3, wherein A plurality of the loading plates (13) are arranged in sequence along a first preset direction, and a plurality of the bearing plates (31) are arranged in sequence along the first preset direction; the plurality of the loading plates (13) are arranged in one-to-one correspondence with the plurality of the bearing plates (31), and each of the loading plates (13) is arranged opposite to the corresponding bearing plate (31).

5. The test device according to claim 3, wherein, The test body (1) comprises a plurality of second driving members (15), the plurality of second driving members (15) are arranged in one-to-one correspondence with the plurality of bearing plates (31), and a second output shaft (151) of each of the second driving members (15) is drivingly connected with the bearing plate (31) so that the second driving member (15) drives the bearing plate (31) to move linearly back and forth. The bearing plate (31) is rotationally connected with the second output shaft (151) so as to be in close contact with the containing part (12) when the bearing plate (31) bears the containing part (12); and / or, The bearing plate (31) comprises a second main plate and a second contact part arranged on the second main plate, and the second contact part is a flexible member so as to be in contact with the containing part (12) when the bearing plate (31) supports the containing part (12).

6. The burst storage property testing device according to claim 1 or 2, wherein The test body (1) comprises a main body part (16), a first structure (17), a second structure (18), a first piston (19) and a second piston (193), the main body part (16) has the confining pressure cavity (11), and the containing part (12) is connected with the main body part (16); The first structure (17) is connected with the main body part (16), the first structure (17) has a first cavity (171), the first cavity (171) is in communication with the containing cavity (121), and the first piston (19) is movably arranged in the first cavity (171) and the containing cavity (121); The second structure (18) is connected with the main body part (16), the second structure (18) and the first structure (17) are located on opposite sides of the main body part (16); the second structure (18) has a second cavity (181), the second cavity (181) is in communication with the containing cavity (121), and the second piston (193) is movably arranged in the second cavity (181) and the containing cavity (121) so that the first piston (19) and the second piston (193) clamp the test piece (20) located in the containing cavity (121).

7. The test device according to claim 6, wherein, The second communication port assembly comprises a third communication port (111) for vacuumizing; the test body (1) further comprises a first piston rod (10), a first end of the first piston rod (10) is connected with the first piston (19), a second end of the first piston rod (10) is arranged outside the first structure (17) through the first structure (17); the test body (1) has a first through hole (102), the first through hole (102) passes through the first piston rod (10) and the first piston (19) in sequence, one end of the first through hole (102) at the second end of the first piston rod (10) is the third communication port (111), the other end of the first through hole (102) is connected with the accommodating cavity (121) between the first piston (19) and the second piston (193); and / or, The second communication port assembly comprises a fourth communication port (103) for water injection; the test body (1) further comprises a second piston rod (104), a first end of the second piston rod (104) is connected with the second piston (193), a second end of the second piston rod (104) is arranged outside the second structure (18) through the second structure (18); the test body (1) has a second through hole (106), the second through hole (106) passes through the second piston rod (104) and the second piston (193) in sequence, one end of the second through hole (106) at the second end of the second piston rod (104) is the fourth communication port (103), the other end of the second through hole (106) is connected with the accommodating cavity (121) between the first piston (19) and the second piston (193); and / or, The first structure (17) is provided with a first oil inlet (172), a first oil cavity (191) is surrounded between the first piston (19) and the first structure (17), the first oil cavity (191) is connected with the first oil inlet (172), so that the first piston (19) makes reciprocating linear motion by adjusting the amount of oil entering the first oil cavity (191) through the first oil inlet (172); and / or, The second structure (18) is provided with a second oil inlet (182), a second oil cavity (192) is surrounded between the second piston (193) and the second structure (18), the second oil cavity (192) is connected with the second oil inlet (182), so that the second piston (193) makes reciprocating linear motion by adjusting the amount of oil entering the second oil cavity (192) through the second oil inlet (182); and / or, The test body (1) further comprises a first sealing member (107), the first sealing member (107) is connected with the accommodating portion (12) and is arranged around the accommodating portion (12), the first sealing member (107) is clamped between the main body portion (16) and the first structure (17); and / or, The test body (1) further comprises a second sealing member (108) connected with the accommodating portion (12) and arranged around the accommodating portion (12), the second sealing member (108) being clamped between the main body portion (16) and the second structure (18).

8. The test device according to any one of claims 1 to 2, wherein, The first communication port assembly comprises a first communication port (109), and the test device further comprises a first vacuum pump (40) connected with the first communication port (109); and / or, The first communication port assembly comprises a second communication port (110), and the test device further comprises a first constant-speed constant-pressure pump (50) connected with the second communication port (110) to inject water into the confining pressure cavity (11) through the second communication port (110); and / or, The second communication port assembly comprises a third communication port (111), and the test device further comprises a second vacuum pump (60) connected with the third communication port (111); and / or, The second communication port assembly comprises a fourth communication port (103), and the test device further comprises a second constant-speed constant-pressure pump (70) connected with the fourth communication port (103) to inject water into the accommodating cavity (121) through the fourth communication port (103).

9. A method of testing the hydrohead characteristics of a tissue, characterized by, The test method is suitable for the test device according to any one of claims 1 to 8, and the test method comprises the following steps: Step S110: Based on the thickness and length of the overlying strata, the width of the coal pillar, the height of the goaf, and the pressure of the overlying strata, according to the similarity criterion C... τ =C σ C l / C h =1, C σ =1, and C M =C σ (C) l / C h ) 2 =1 Determine the length l and thickness h of the specimen (20), the simulated width x of the coal pillar, the simulated height y of the goaf, and the applied load of the loading plate (13); where, C τ For the shear stress similarity scale, C σ For the compressive stress similarity scale, C M For the bending stress similarity scale, C l and C h These are the similarity scales for the length and thickness of the overlying strata, respectively. In step S120, the number of annular structures n is adjusted according to the length l of the test piece (20), so that the total length l' of n annular structures is equal to the length l of the test piece (20), and one annular structure is arranged on the left and right sides of the n annular structures for coal pillar support simulation, so that the total number of annular structures is n+2; wherein the loading plate (13) and the bearing plate (31) correspond to one annular structure; In step S130, the test piece (20) with a length of l'+2x and a thickness of h is obtained by coring and processing on site, and the initial apparent volume V0 of the test piece (20) is obtained by the drainage method; wherein the length of one annular structure on the left and right sides of the n annular structures is equal to the coal pillar simulation width x; In step S140, the loading plate (13) and the bearing plate (31) are adjusted to be horizontal, the test piece (20) processed in step S130 is loaded, and the test piece (20) is adjusted to the middle position and clamped by the first piston (19) and the second piston (193), so that the contact length of the test piece (20) with the bearing plate (31) on the left and right sides of the n annular structures is equal to the coal pillar simulation width x; In step S140, the loading plate (13) and the bearing plate (31) are adjusted to be horizontal, the test piece (20) processed in step S130 is loaded, and the test piece (20) is adjusted to the middle position and clamped by the first piston (19) and the second piston (193), so that the contact length of the test piece (20) with the bearing plate (31) on the left and right sides of the n annular structures is equal to the coal pillar simulation width x; Step S150, the first vacuum pump (40) and the second vacuum pump (60) are used to respectively vacuum the confining pressure cavity (11) and the containing cavity (121); Step S160, the first constant speed and constant pressure pump (50) is used to inject water with constant pressure into the confining pressure cavity (11), and the water volume change △V1 in the confining pressure cavity (11) is monitored in real time; then the second constant speed and constant pressure pump (70) is used to inject water with pressure less than that in the confining pressure cavity (11) into the containing cavity (121), and the injected water volume V2 is monitored in real time; Step S170, the load applied by the loading plate (13) is applied to the test piece (20) according to the load determined in step S110; Step S180, the initial apparent volume V0 of the test piece (20) obtained in step S130, the water volume change △V1 in the confining pressure cavity (11) and the real-time injected water volume V2 in the containing cavity (121) obtained in step S160 are used to obtain the dynamic water storage characteristics of the test piece (20) through the formula V2 / V0, and the dynamic crush expansion characteristics of the test piece (20) through the formula (△V1+ V0) / V0.

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