Testing device for testing relationship between fractured rock mass damage and permeability change

Abstract

The utility model relates to a test device for testing a relationship between fractured rock mass damage and permeability change. A bidirectional loading unit comprises a sample underframe, a long-end fixing plate, a wide-end fixing plate, a lateral pressure transmission mechanism and a manual turbine loading device, the sample underframe is of an I-shaped structure; the two long-end fixing plates are oppositely fixed on the outer sides of the two ends of the sample underframe in the length direction; the two wide-end fixing plates are oppositely fixed on the front side and the rear side of the web plate on the sample underframe; the two lateral pressure transmission mechanisms are oppositely distributed left and right; the lateral pressure transmission mechanism comprises a lateral pressure plate, a main guide rod, a pressure bearing end and an auxiliary guide rod; the manual turbine loading device comprises two lateral counter-force plates, two lateral counter-force reinforcing rods, two manual turbine speed reducers, two flexible pressurizing plates and two pressure sensors; the vertical loading unit comprises an upper pressing plate, a dowel bar and a variable cross-section connector; and the permeation unit comprises two glass plates. The device can be used for testing the deformation, fracture, strength and permeation characteristics of the fractured rock mass sample under different confining pressures.

Description

Technical Field

[0001] This invention belongs to the technical field of rock mass testing equipment, specifically relating to a test device for testing the relationship between damage and permeability changes in fractured rock mass. Background Technology

[0002] In actual underground engineering, fractured rock masses are typically rich in various weak structural surfaces such as joints and fissures. When excavation activities are carried out within these masses, the fractured rock masses within the affected area will suffer varying degrees of damage, resulting in significant changes in their strength and permeability. If adverse geological structures such as water-rich karst caves, underground rivers, faults, or collapse columns exist in the surrounding area, collapse instability and water inrush accidents can easily occur, leading to severe losses to the project. Therefore, studying the relationship between damage and permeability changes in fractured rock masses under different confining pressures is of great significance for ensuring the safety of underground engineering projects under water-rich conditions. Traditional methods typically employ a rock servo triaxial testing system to measure the permeability of rocks during the full stress-strain process. However, this method has several drawbacks: ① The rock servo triaxial testing system is expensive and complex to operate, hindering its widespread adoption; ② The test samples are generally intact rocks, rarely with pre-existing joints and fissures, making it difficult to reflect the naturally occurring weak structural features of fractured rock masses in actual engineering projects; ③ During the test, the deformation and fracture propagation characteristics of the sample surface cannot be directly observed, making it difficult to analyze the damage and failure of the fractured rock mass, and even more difficult to obtain the relationship between fractured rock mass damage and permeability. Therefore, given that traditional methods cannot adequately address the relationship between fractured rock mass damage and permeability, and cannot provide crucial support for the safe and stable control of underground engineering under water-rich conditions, there is an urgent need for a testing device capable of measuring the deformation, fracture, strength, and permeability characteristics of fractured rock mass samples under different confining pressures. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention provides a test device for testing the relationship between damage and permeability changes in fractured rock mass. The device has a reasonable structure and good stability. It can not only perform vertical loading tests on fractured rock mass samples or similar materials, but also perform lateral unloading tests on fractured rock mass samples or similar materials. Using this device, the deformation, fracture, and permeability change characteristics of fractured rock mass samples under different stress states can be tested.

[0004] To achieve the above-mentioned objectives, the present invention provides an experimental device for testing the relationship between damage and permeability changes in fractured rock mass, comprising a test platform base plate, a bidirectional loading unit, a vertical loading unit, and a permeability unit;

[0005] The base plate of the test platform is placed horizontally;

[0006] The bidirectional loading unit includes a sample base frame, two long-end fixing plates, two wide-end fixing plates, two lateral pressure transmission mechanisms, and a manual turbine loading device.

[0007] The sample base frame has an I-shaped structure and is horizontally fixed in the upper center area of ​​the test platform base plate; the front and rear sides of the web plate of the sample base frame are inlaid with water-stop rubber, and two bolt holes C are opened opposite to each other on the left and right sides of the web plate; the two wing plates at both ends of the length direction of the sample base frame are provided with a pair of bolt holes A opposite to each other on the front and rear sides of the web plate.

[0008] Two long-end fixing plates are distributed opposite each other on the outer sides of both ends of the sample base frame along its length. The long-end fixing plates are rectangular plates and are vertically arranged. The bottom of the long-end fixing plates has a pair of bolt holes B corresponding to a pair of bolt holes A. The top of the plates has a pair of bolt holes F corresponding to the outer sides of the pair of bolt holes B. A large guide hole is provided in the center area. Two small guide holes are symmetrically provided on the upper and lower sides of the large guide hole. The lower ends of the two long-end fixing plates are fixedly connected to the wing plates at both ends of the sample base frame along its length by two connecting bolts A passing through the two bolt holes B and the two bolt holes A. The two bolt holes F on the same side of the front and rear directions of the two long-end fixing plates form two sets of upper fixing holes respectively.

[0009] Two wide-end fixing plates are distributed opposite each other on the front and rear sides of the web of the sample base. Each wide-end fixing plate includes a wide-end fixing frame and extension arms. The wide-end fixing frame is rectangular, with a rectangular window in its central area and two bolt holes D corresponding to the two bolt holes C at its bottom. The extension arms are L-shaped, symmetrically distributed on the left and right sides of the upper end of the wide-end fixing frame. The transverse sections of the two extension arms are fixedly connected to the upper end of the fixing frame, and two connecting holes are oppositely formed on the inner sides of the two transverse sections. The longitudinal sections of the two extension arms extend to the same side and... A pair of bolt holes E are provided opposite to a set of upper fixing holes; the bottom of the two wide-end fixing plates are fixedly connected to the web plate on the sample base frame by two connecting bolts B passing through two bolt holes D and two bolt holes C; the top ends of the two wide-end fixing plates are fixedly connected to the top of the two long-end fixing plates by two connecting bolts C passing through a pair of bolt holes E and a set of upper fixing holes; the middle top sections of the two wide-end fixing plates are fixedly connected to each other by two connecting screws passing through two pairs of connecting holes; a sample receiving cavity with openings at the left and right ends and the top is formed between the sample base frame and the two wide-end fixing plates.

[0010] Two lateral pressure transmission mechanisms are distributed opposite each other on the left and right sides. Each lateral pressure transmission mechanism includes a side pressure plate, a main guide rod, a pressure-bearing end, and a secondary guide rod. The width of the side pressure plate is adapted to the width of the sample receiving cavity, and its inner end is inserted into the side end of the sample receiving cavity and slides and seals with the two wide-end fixing plates. At the same time, two water-stop rubbers are embedded in the inner end of the side pressure plate along the front and rear sides. The main guide rod is horizontally and slidably inserted into the large guide hole, and its inner end is fixedly connected to the center of the outer edge of the side pressure plate through a variable cross-section connector. The pressure-bearing end is located on the outside of the long end fixing plate on the same side and is fixedly connected to the outer end of the main guide rod. The two secondary guide rods are symmetrically distributed on the upper and lower sides of the main guide rod and are horizontally and slidably inserted into the two small guide holes.

[0011] The manual turbine loading device includes two lateral reaction plates, two lateral reaction reinforcement rods, two manual turbine reducers, two flexible pressure plates, and two pressure sensors. The two lateral reaction plates are correspondingly distributed on the outer sides of two long-end fixed plates. Each lateral reaction plate is I-shaped, with a sliding through-hole in its center. Multiple bolt holes I are formed around the sliding through-hole in its middle section. Bolt holes G are formed oppositely at the front and rear ends of its upper transverse arm, and bolt holes H are formed oppositely at the front and rear ends of its lower transverse arm. The lateral reaction plates are fixedly connected to the test platform base plate by two connecting bolts D passing through the two bolt holes H. The two lateral reaction reinforcement rods are distributed opposite each other, each lateral reaction reinforcement rod... Both ends are threaded sections, and both threaded sections pass through two bolt holes I on the same side. Additionally, each threaded section is connected to two lock nuts on both sides of the lateral reaction plate via threaded engagement. Two manual worm gear reducers are correspondingly distributed on the outer sides of the two lateral reaction plates. The manual worm gear reducers are fixedly connected to the lateral reaction plates via connecting bolts E passing through multiple bolt holes I. Simultaneously, the worm gear in the manual worm gear reducer can slidably pass into the inner side of the lateral reaction plate through a sliding through-hole. Two flexible pressure plates are correspondingly distributed on the outer sides of the two lateral pressure transmission mechanisms and are respectively fixedly connected to the inner ends of the worm gears in the two manual worm gear reducers. Two pressure sensors are respectively connected to the inner sides of the two flexible pressure plates.

[0012] The vertical loading unit includes an upper pressure plate, a force transmission rod, and a variable cross-section connector. The width of the upper pressure plate is adapted to the width of the sample receiving cavity, and its lower end is inserted into the side end of the sample receiving cavity and slides and seals with the two wide-end fixing plates. At the same time, two water-stop rubber strips are embedded in the lower end of the upper pressure plate along the front and rear sides. The force transmission rod is vertically arranged, and its lower end is fixedly connected to the upper end of the upper pressure plate through the variable cross-section connector.

[0013] The permeation unit includes two glass plates; the two glass plates are respectively fixedly installed in rectangular windows of two wide-end fixed frames, wherein the front glass plate has a water inlet hole in the middle and the rear glass plate has a water outlet hole at the bottom.

[0014] As a preferred embodiment, the base plate of the test platform is a rectangular steel plate.

[0015] Furthermore, to facilitate assembly and maintenance, the wide-end fixed frame has multiple bolt holes J around the rectangular window; the glass plate is fixedly connected to the wide-end fixed frame by multiple connecting bolts F passing through the multiple bolt holes J.

[0016] Furthermore, to ensure the reliability of the test, the test platform base plate, sample base frame, long end fixing plate, wide end fixing plate, side pressure plate, lateral reaction plate and upper pressure plate are all made of steel plate.

[0017] Furthermore, in order to ensure that the injected water can be evenly diffused to the entire surface of the sample, and at the same time, to ensure that the seeping water flows out of the water outlet without obstruction, the inner side of the glass plate is evenly provided with several vertical grooves along the length direction.

[0018] Furthermore, in order to facilitate water injection operations under rated water pressure conditions, and to facilitate the sensing of water flow through the fractured rock mass under rated water pressure conditions, thereby facilitating the determination of the permeability of the fractured rock mass under different confining pressure conditions, a stabilizing pump and a flow meter are also included. The inlet end of the stabilizing pump is connected to the water tank through an inlet pipe, and its outlet end is connected to the inlet hole on the front glass plate through a water supply pipe. A drain pipe is connected to the outer end of the outlet hole on the rear glass plate, and the flow meter is connected in series on the drain pipe.

[0019] Furthermore, in order to observe the deformation and fracture characteristics of the fractured rock mass sample surface through digital photogrammetry, so as to combine the stress state analysis of the sample rock mass to obtain the damage and permeability evolution of the fractured rock mass sample under different confining pressure conditions, a high-definition camera is also included, which is installed behind the glass plate on the rear side.

[0020] Furthermore, to facilitate automated control processes, a controller is also included, which is connected to a pressure sensor, a flow meter, a camera, and a stabilizing water pump.

[0021] As a preferred embodiment, the controller is an industrial computer.

[0022] In this invention, by setting a test platform base plate, a fixed foundation can be provided for the bidirectional loading unit, thereby ensuring the stability and reliability of bidirectional loading. Two bolt holes C are provided on the web of the sample base frame, and two bolt holes D corresponding to the two bolt holes C are provided on the bottom of the two wide-end fixing plates. This facilitates the use of connecting bolts to fix the two wide-end fixing plates to the front and rear sides of the web of the sample base plate, thus forming a three-way open sample receiving cavity between the sample base frame and the two wide-end fixing plates. This sample receiving cavity provides loading space for the rock sample. Water-stop rubber is embedded on both sides of the web of the sample base frame, effectively ensuring the sealing performance at the connection between the sample base frame and the two wide-end fixing plates, helping to prevent water leakage from the bottom of the sample receiving cavity. A pair of bolt holes A are provided on the two wing plates of the sample base frame, and a pair of bolt holes B corresponding to the pair of bolt holes A are provided on the bottom of the two long-end fixing plates. This facilitates the use of connecting bolts to fix the two long-end fixing plates to the two wing plates of the sample base plate. A large guide hole and two small guide holes are provided on the long-end fixing plate to facilitate guiding and supporting the sample. The wide-end fixing plate consists of a wide-end fixing frame and two extension arms. This allows for easy connection between the two extension arms and the two long-end fixing plates, effectively increasing the stability of the connection between the sample base, the two wide-end fixing plates, and the two long-end fixing plates. This enhances the constraint between the sample base and each fixing plate, ensuring the overall stability of the sample cavity. Furthermore, the two extension arms create a gap between the wide-end fixing frame and the long-end fixing plates, facilitating the assembly of the lateral pressure transmission mechanism. The main guide rod and two auxiliary guide rods in the lateral pressure transmission mechanism are slidably assembled in the large guide hole and the two small guide holes. Simultaneously, the side pressure plate is slidably and sealingly assembled inside the side opening of the sample cavity. This ensures that the lateral pressure transmission mechanism can only undergo lateral displacement in the left-right direction, without any lateral position in the front-back direction, thus ensuring the stability and reliability of lateral loading. By fixing a bearing end to the outer end of the main axial rod, the bearing end can be used to receive and transmit force, which is then transferred to the side pressure plate via the main axial rod. Simultaneously, the lateral reaction force can be transmitted to the force sensor on the outside via the main axial rod and the bearing end, facilitating real-time acquisition of the lateral stress state of the fractured rock mass. Water-stop rubber is embedded on both sides of the inner end of the side pressure plate to ensure a sliding seal between the side pressure plate and the two wide-end fixed plates, preventing water leakage during lateral loading. Two lateral reaction plates are fixedly installed on the outside of the two long-end fixed plates, and connected by two lateral reaction reinforcement rods, effectively ensuring the connection strength of the lateral reaction plates and thus providing a stable reaction force application effect. Sliding through holes are provided on the lateral reaction plates to facilitate guidance of the worm gear.Two manual worm gear reducers are fixedly installed on the outer sides of the two lateral reaction plates, and the worms of the manual worm gear reducers are slidably inserted into the sliding through holes. A pressure sensor and a flexible pressure plate are then installed on the inner end of the worms. This allows for manual cranking control of the worms on both sides to move in opposite directions, thereby pushing the two lateral force transmission mechanisms to move in opposite directions, facilitating the application of lateral loading forces to the fractured rock mass. The upper pressure plate of the vertical loading unit is slidably inserted into the inner side of the upper opening of the sample receiving cavity. Water-stop rubber strips are embedded on both the front and rear sides of the lower edge of the upper pressure plate to ensure the sealing performance between the upper pressure plate and the two wide-end fixed plates, preventing water leakage from the upper opening of the sample during vertical loading. The force transmission rod is fixedly connected to the upper end of the upper pressure plate via a variable cross-section connector, facilitating good integration with traditional servo presses. This allows for convenient application of vertical loads to the fractured rock mass and real-time testing of the current vertical stress state of the fractured rock mass. A water inlet is provided in the middle of the front glass plate, and a water outlet is provided at the bottom of the rear glass plate. This allows for easy water injection under rated pressure conditions using the water inlet, and also facilitates the collection of seepage flow rate using the water outlet. This makes it easy to obtain the water flow rate through the fractured rock mass under rated water pressure conditions.

[0023] The device has a reasonable structure and good stability. It can not only conduct vertical loading tests on fractured rock samples or similar materials, but also conduct lateral unloading tests on fractured rock samples or similar materials. Using this device, the deformation, fracture, and permeability variation characteristics of fractured rock samples under different stress states can be tested. It has many advantages such as being economical and flexible, easy to operate, and easy to promote. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of this utility model. Figure 1 ;

[0025] Figure 2 This is a schematic diagram of the structure of this utility model. Figure 2 ;

[0026] Figure 3 This is a schematic diagram of the assembly of the two lateral force transmission mechanisms and the fractured rock mass sample in this utility model.

[0027] In the diagram: 1. Force transmission rod, 2. Variable cross-section connector one, 3. Side pressure plate, 4. Water-stop rubber two, 5. Guiding rod, 6. Main guiding rod, 7. Pressure bearing end, 8. Locking nut, 9. Lateral reaction force reinforcing rod, 10. Connecting screw, 11. Connecting bolt C, 12. Pressure sensor, 13. Manual worm gear reducer, 14. Worm gear, 15. Flexible pressure plate, 16. Connecting bolt B, 17. Water outlet, 18. Connecting bolt F, 19. Glass plate, 20. Connecting bolt A, 21. Connecting bolt E, 22. Connecting bolt D, 23. Test platform base plate, 24. Small guide hole, 25. Screw 26. Bolt hole F, 27. Large guide hole, 28. Bolt hole B, 29. Bolt hole A, 30. Bolt hole C, 31. Sliding through hole, 32. Bolt hole G, 33. Bolt hole I, 34. Bolt hole H, 35. Connecting hole, 36. Bolt hole E, 37. Water inlet hole, 38. Water-stop rubber three, 39. Bolt hole J, 40. Bolt hole D, 41. Sample base frame, 42. Long end fixing plate, 43. Wide end fixing plate, 44. Extension arm, 45. Wide end fixing frame, 46. Lateral pressure transmission mechanism, 47. Lateral reaction plate, 48. Upper pressure plate, 49. Water-stop rubber one, 40. Variable cross-section connector two. Detailed Implementation

[0028] The invention will now be further described with reference to the accompanying drawings.

[0029] like Figures 1 to 3 As shown, the present invention provides an experimental device for testing the relationship between damage and permeability changes in fractured rock mass, including an experimental platform base plate 23, a bidirectional loading unit, a vertical loading unit, and a permeability unit;

[0030] The test platform base plate 23 is placed horizontally;

[0031] The bidirectional loading unit includes a sample base frame 40, two long-end fixing plates 41, two wide-end fixing plates 42, two lateral pressure transmission mechanisms 45, and a manual turbine loading device.

[0032] The sample base frame 40 has an I-shaped structure and is horizontally fixed in the upper center area of ​​the test platform base plate 23. Water-stop rubber 48 is embedded on both the front and rear sides of the upper web of the sample base frame 40, and two bolt holes C29 are opened opposite each other on the left and right sides of the web. The two wing plates at both ends of the sample base frame 40 in the length direction have a pair of bolt holes A28 opposite each other on the front and rear sides of the web.

[0033] Two long-end fixing plates 41 are distributed opposite each other on the outer sides of both ends of the sample base frame 40 along its length. The long-end fixing plates 41 are rectangular plates and are vertically arranged. The bottom of the long-end fixing plates 41 has a pair of bolt holes B27 corresponding to a pair of bolt holes A28. The top of the long-end fixing plates 41 has a pair of bolt holes F25 corresponding to the outer sides of the pair of bolt holes B27. A large guide hole 26 is provided in the central area. Two small guide holes 24 are symmetrically provided on the upper and lower sides of the large guide hole 26. The lower ends of the two long-end fixing plates 41 are fixedly connected to the wing plates at both ends of the sample base frame 40 along its length by two connecting bolts A20 passing through the two bolt holes B27 and the two bolt holes A28. The two bolt holes F25 on the same side of the front and rear directions of the two long-end fixing plates 41 respectively form two sets of upper fixing holes.

[0034] Two wide-end fixing plates 42 are distributed opposite to each other on the front and rear sides of the web of the sample base 40. Each wide-end fixing plate 42 includes a wide-end fixing frame 44 and an extension arm 43. The wide-end fixing frame 44 is rectangular, with a rectangular window in its central area and two bolt holes D39 corresponding to the positions of the two bolt holes C29 at its bottom. The extension arm 43 is L-shaped, with two extension arms 43 symmetrically distributed on the left and right sides of the upper end of the wide-end fixing frame 44. The transverse sections of the two extension arms 43 are fixedly connected to the upper end of the fixing frame 44. Simultaneously, two connecting holes 34 are opened opposite to each other on the inner sides of the two transverse sections. The longitudinal sections of the two extension arms 43 extend to the same side and... A pair of bolt holes E35 are provided opposite to a set of upper fixing holes; the bottom of the two wide-end fixing plates 42 are fixedly connected to the web plate on the sample base 40 by two connecting bolts B16 passing through two bolt holes D39 and two bolt holes C29; the top ends of the two wide-end fixing plates 42 are fixedly connected to the top of the two long-end fixing plates 41 by two connecting bolts C11 passing through a pair of bolt holes E35 and a set of upper fixing holes; the middle section of the top of the two wide-end fixing plates 42 is fixedly connected to each other by two connecting screws 10 passing through two pairs of connecting holes 34; a sample receiving cavity with openings at the left and right ends and the top is formed between the sample base 40 and the two wide-end fixing plates 42.

[0035] Two lateral pressure transmission mechanisms 45 are distributed opposite each other on the left and right sides. Each lateral pressure transmission mechanism 45 includes a side pressure plate 3, a main guide rod 6, a pressure-bearing end 7, and a guide rod 5. The width of the side pressure plate 3 is adapted to the width of the sample receiving cavity, and its inner end is inserted into the side end of the sample receiving cavity and slides and seals with the two wide-end fixing plates 42. At the same time, two water-stop rubber 4s are embedded in the inner side of the side pressure plate 3 along the front and rear sides. The main guide rod 6 is horizontally slidably inserted into the large guide hole 26, and its inner end is fixedly connected to the center of the outer edge of the side pressure plate 3 through a variable cross-section connector 49. The pressure-bearing end 7 is located outside the long end fixing plate 41 on the same side and is fixedly connected to the outer end of the main guide rod 6. The two guide rods 5 are symmetrically distributed on the upper and lower sides of the main guide rod 6 and are horizontally slidably inserted into the two small guide holes 24.

[0036] The manual turbine loading device includes two lateral reaction plates 46, two lateral reaction reinforcing rods 9, two manual turbine reducers 13, two flexible pressure plates 15, and two pressure sensors 12. The two lateral reaction plates 46 are distributed on the outer sides of the two long-end fixed plates 41. The lateral reaction plates 46 are I-shaped, with a sliding through hole 30 in the center. Multiple bolt holes I32 are formed around the sliding through hole 30 in the middle part. Bolt holes G31 are formed at the front and rear ends of the upper transverse arm, and bolt holes H33 are formed at the front and rear ends of the lower transverse arm. The lateral reaction plates 46 are fixedly connected to the test platform base plate 23 by two connecting bolts D22 passing through the two bolt holes H33. The two lateral reaction reinforcing rods 9 are distributed front and rear opposite each other. Both ends are threaded sections, and both threaded sections pass through two bolt holes I32 on the same side. At the same time, each threaded section is connected to two locking nuts 8 on both sides of the lateral reaction plate 46 by threaded engagement. Two manual worm gear reducers 13 are correspondingly distributed on the outer side of the two lateral reaction plates 46. The manual worm gear reducers 13 are fixedly connected to the lateral reaction plates 46 by connecting bolts E21 passing through multiple bolt holes I32. At the same time, the worm gear 14 in the manual worm gear reducer 13 can slide into the inner side of the lateral reaction plate 46 through the sliding through hole 30. Two flexible pressure plates 15 are correspondingly distributed on the outer side of the two lateral pressure transmission mechanisms 45 and are respectively fixedly connected to the inner end of the worm gear 14 in the two manual worm gear reducers 13. Two pressure sensors 12 are respectively connected to the inner side of the two flexible pressure plates 15.

[0037] The vertical loading unit includes an upper pressure plate 47, a force transmission rod 1, and a variable cross-section connector 2. The width of the upper pressure plate 47 is adapted to the width of the sample receiving cavity, and its lower end is inserted into the side end of the sample receiving cavity and slides and seals with the two wide-end fixing plates 42. At the same time, two water-stop rubber 37s are embedded in the lower end of the upper pressure plate 47 along the front and rear sides. The force transmission rod 1 is vertically arranged, and its lower end is fixedly connected to the upper end of the upper pressure plate 47 through the variable cross-section connector 2.

[0038] The permeation unit includes two glass plates 19; the two glass plates 19 are respectively fixedly installed in the rectangular windows of two wide-end fixed frames 44, wherein the front glass plate 19 has a water inlet hole 36 in the middle and the rear glass plate 19 has a water outlet hole 17 at the bottom.

[0039] As a preferred embodiment, the test platform base plate 23 is a rectangular steel plate.

[0040] To facilitate assembly and maintenance, the wide-end fixed frame 44 has multiple bolt holes J38 around the rectangular window; the glass plate 19 is fixedly connected to the wide-end fixed frame 44 by multiple connecting bolts F18 passing through the multiple bolt holes J38.

[0041] To ensure the reliability of the test, the test platform base plate 23, sample base frame 40, long end fixing plate 41, wide end fixing plate 42, side pressure plate 3, lateral reaction plate 46 and upper pressure plate 47 are all made of steel plate.

[0042] In order to ensure that the injected water can be evenly diffused to the entire surface of the sample, and to ensure that the seeping water can flow out of the water outlet without obstruction, the inner side of the glass plate 19 is evenly provided with several vertical grooves along the length direction.

[0043] To facilitate water injection under rated water pressure conditions and to easily detect the outflow rate through the fractured rock mass under rated water pressure conditions, thereby easily obtaining the permeability of the fractured rock mass under different confining pressure conditions, a stabilizing pump and a flow meter are also included. The inlet of the stabilizing pump is connected to the water tank through an inlet pipe, and its outlet is connected to the inlet hole 36 on the front glass plate 19 through a water supply pipe. A drain pipe is connected to the outer end of the outlet hole 17 on the rear glass plate 19, and the flow meter is connected in series on the drain pipe.

[0044] In order to observe the deformation and fracture characteristics of the surface of the fractured rock mass sample through digital photogrammetry, and to combine the stress state analysis of the sample rock mass to obtain the damage and permeability evolution of the fractured rock mass sample under different confining pressure conditions, a high-definition camera is also included, which is installed behind the glass plate 19 on the rear side.

[0045] To facilitate automated control processes, a controller is also included, which is connected to the pressure sensor 12, the flow meter, the camera, and the stabilizing water pump.

[0046] As a preferred embodiment, the controller is an industrial computer.

[0047] In use, firstly, a fractured rock mass sample measuring 100mm × 100mm × 10mm is prepared in an iron box with an internal space of 105mm × 105mm × 10mm by hammering and cutting. Next, the sample base frame, two wide-end fixing plates, two long-end fixing plates, two lateral pressure transmission mechanisms, a manual turbine loading device, and a permeation unit are assembled into a single testing device, and the fractured rock mass sample is placed into the sample receiving cavity. Then, the vertical loading unit is assembled at the upper end of the sample receiving cavity. Next, the lateral force transmission mechanism and the vertical loading unit are initially adjusted so that the side pressure plates and upper pressure plates move from the side and top towards the center of the sample receiving cavity and initially contact the fractured rock mass sample. Finally, the loading block of the servo press and the force transmission mechanism are connected... The upper end of the rod is connected, and the flexible pressure plate at the end of the worm gear of the manual worm gear reducer is connected to the pressure-bearing end in the lateral force transmission mechanism. The water injection hole is connected to the stabilizing water pump, and the water outlet is connected to the drainage pipe connected in series with a flow meter. A high-definition camera is set up behind the rear glass plate and connected to the controller to facilitate the observation and analysis of the deformation and fracture characteristics of the rear surface of the fractured rock mass sample. Finally, the handwheel on the manual worm gear reducer is turned on to apply a predetermined lateral pressure to the fractured rock mass sample, and the conventional servo press is controlled to slowly load the fractured rock mass sample vertically. The stabilizing water pump is turned on, and the flow meter values ​​are recorded under different pressure states during the test. When the fractured rock mass sample is re-fractured and the pressure change displayed by the servo press is not obvious, the test is stopped and the stabilizing water pump is turned off.

[0048] In this invention, by setting a test platform base plate, a fixed foundation can be provided for the bidirectional loading unit, thereby ensuring the stability and reliability of bidirectional loading. Two bolt holes C are provided on the web of the sample base frame, and two bolt holes D corresponding to the two bolt holes C are provided on the bottom of the two wide-end fixing plates. This facilitates the use of connecting bolts to fix the two wide-end fixing plates to the front and rear sides of the web of the sample base plate, thus forming a three-way open sample receiving cavity between the sample base frame and the two wide-end fixing plates. This sample receiving cavity provides loading space for the rock sample. Water-stop rubber is embedded on both sides of the web of the sample base frame, effectively ensuring the sealing performance at the connection between the sample base frame and the two wide-end fixing plates, helping to prevent water leakage from the bottom of the sample receiving cavity. A pair of bolt holes A are provided on the two wing plates of the sample base frame, and a pair of bolt holes B corresponding to the pair of bolt holes A are provided on the bottom of the two long-end fixing plates. This facilitates the use of connecting bolts to fix the two long-end fixing plates to the two wing plates of the sample base plate. A large guide hole and two small guide holes are provided on the long-end fixing plate to facilitate guiding and supporting the sample. The wide-end fixing plate consists of a wide-end fixing frame and two extension arms. This allows for easy connection between the two extension arms and the two long-end fixing plates, effectively increasing the stability of the connection between the sample base, the two wide-end fixing plates, and the two long-end fixing plates. This enhances the constraint between the sample base and each fixing plate, ensuring the overall stability of the sample cavity. Furthermore, the two extension arms create a gap between the wide-end fixing frame and the long-end fixing plates, facilitating the assembly of the lateral pressure transmission mechanism. The main guide rod and two auxiliary guide rods in the lateral pressure transmission mechanism are slidably assembled in the large guide hole and the two small guide holes. Simultaneously, the side pressure plate is slidably and sealingly assembled inside the side opening of the sample cavity. This ensures that the lateral pressure transmission mechanism can only undergo lateral displacement in the left-right direction, without any lateral position in the front-back direction, thus ensuring the stability and reliability of lateral loading. By fixing a bearing end to the outer end of the main axial rod, the bearing end can be used to receive and transmit force, which is then transferred to the side pressure plate via the main axial rod. Simultaneously, the lateral reaction force can be transmitted to the force sensor on the outside via the main axial rod and the bearing end, facilitating real-time acquisition of the lateral stress state of the fractured rock mass. Water-stop rubber is embedded on both sides of the inner end of the side pressure plate to ensure a sliding seal between the side pressure plate and the two wide-end fixed plates, preventing water leakage during lateral loading. Two lateral reaction plates are fixedly installed on the outside of the two long-end fixed plates, and connected by two lateral reaction reinforcement rods, effectively ensuring the connection strength of the lateral reaction plates and thus providing a stable reaction force application effect. Sliding through holes are provided on the lateral reaction plates to facilitate guidance of the worm gear.Two manual worm gear reducers are fixedly installed on the outer sides of the two lateral reaction plates, and the worms of the manual worm gear reducers are slidably inserted into the sliding through holes. A pressure sensor and a flexible pressure plate are then installed on the inner end of the worms. This allows for manual cranking control of the worms on both sides to move in opposite directions, thereby pushing the two lateral force transmission mechanisms to move in opposite directions, facilitating the application of lateral loading forces to the fractured rock mass. The upper pressure plate of the vertical loading unit is slidably inserted into the inner side of the upper opening of the sample receiving cavity. Water-stop rubber strips are embedded on both the front and rear sides of the lower edge of the upper pressure plate to ensure the sealing performance between the upper pressure plate and the two wide-end fixed plates, preventing water leakage from the upper opening of the sample during vertical loading. The force transmission rod is fixedly connected to the upper end of the upper pressure plate via a variable cross-section connector, facilitating good integration with traditional servo presses. This allows for convenient application of vertical loads to the fractured rock mass and real-time testing of the current vertical stress state of the fractured rock mass. A water inlet is provided in the middle of the front glass plate, and a water outlet is provided at the bottom of the rear glass plate. This allows for easy water injection under rated pressure conditions using the water inlet, and also facilitates the collection of seepage flow rate using the water outlet. This makes it easy to obtain the water flow rate through the fractured rock mass under rated water pressure conditions.

[0049] The device has a reasonable structure and good stability. It can not only conduct vertical loading tests on fractured rock samples or similar materials, but also conduct lateral unloading tests on fractured rock samples or similar materials. Using this device, the deformation, fracture, and permeability variation characteristics of fractured rock samples under different stress states can be tested. It has many advantages such as being economical and flexible, easy to operate, and easy to promote.

Claims

1. A test apparatus for testing the relationship between damage and permeability changes in fractured rock mass, comprising a test platform base plate (23), wherein the test platform base plate (23) is placed horizontally; characterized in that, It also includes bidirectional loading units, vertical loading units, and penetration units; The bidirectional loading unit includes a sample base frame (40), two long-end fixing plates (41), two wide-end fixing plates (42), two lateral pressure transmission mechanisms (45), and a manual turbine loading device; The sample base frame (40) has an I-shaped structure and is horizontally fixed in the upper center area of ​​the test platform base plate (23). Water-stop rubber (48) is embedded on both the front and rear sides of the upper web plate of the sample base frame (40), and two bolt holes C (29) are opened opposite to each other on the left and right sides of the web plate. The two wing plates at both ends of the sample base frame (40) in the length direction are provided with a pair of bolt holes A (28) opposite to each other on the front and rear sides of the web plate. Two long-end fixing plates (41) are distributed opposite each other on the outer sides of the two ends of the sample base frame (40) in the length direction. The long-end fixing plates (41) are rectangular plates and are set vertically. The bottom of the long-end fixing plates (41) is provided with a pair of bolt holes B (27) corresponding to a pair of bolt holes A (28). The top of the plates is provided with a pair of bolt holes F (25) corresponding to the outer sides of the pair of bolt holes B (27). A large guide hole (26) is provided in the center area. Two small guide holes (24) are provided symmetrically on the upper and lower sides of the large guide hole (26). The lower ends of the two long-end fixing plates (41) are fixedly connected to the wing plates at both ends of the sample base frame (40) in the length direction by two connecting bolts A (20) passing through the two bolt holes B (27) and the two bolt holes A (28). The two bolt holes F (25) on the same side in the front and rear directions of the two long-end fixing plates (41) respectively form two sets of upper fixing holes. Two wide-end fixing plates (42) are distributed opposite to each other on the front and rear sides of the web of the sample base frame (40). The wide-end fixing plate (42) includes a wide-end fixing frame (44) and an extension arm (43). The wide-end fixing frame (44) is rectangular, with a rectangular window in its central area, and two bolt holes D (39) are correspondingly opened at the bottom of the frame at the position of the two bolt holes C (29). The extension arm (43) is L-shaped, and the two extension arms (43) are symmetrically distributed on the left and right sides of the upper end of the wide-end fixing frame (44). The transverse sections of the two extension arms (43) are fixedly connected to the upper end of the fixing frame (44). At the same time, two connecting holes (34) are opened opposite to each other on the inner side of the two transverse sections. The longitudinal sections of the two extension arms (43) extend to the same side and are aligned with each other. A pair of bolt holes E (35) are provided opposite to a set of upper fixing holes; the bottom of the two wide-end fixing plates (42) are fixedly connected to the web plate on the sample base (40) by two connecting bolts B (16) passing through two bolt holes D (39) and two bolt holes C (29); the top ends of the two wide-end fixing plates (42) are fixedly connected to the top of the two long-end fixing plates (41) by two connecting bolts C (11) passing through a pair of bolt holes E (35) and a set of upper fixing holes; the middle section of the top of the two wide-end fixing plates (42) is fixedly connected to each other by two connecting screws (10) passing through two pairs of connecting holes (34); a sample receiving cavity with openings at the left and right ends and the top is formed between the sample base (40) and the two wide-end fixing plates (42). Two lateral pressure transmission mechanisms (45) are distributed opposite each other on the left and right sides; the lateral pressure transmission mechanism (45) includes a side pressure plate (3), a main guide rod (6), a pressure-bearing end (7) and a guide rod (5); the width of the side pressure plate (3) is adapted to the width of the sample receiving cavity, and its inner end is inserted into the side end of the sample receiving cavity and slides and seals with the two wide end fixing plates (42). At the same time, two water-stop rubbers are embedded on the inner end of the side pressure plate (3) along the front and rear sides. Glue 2 (4); The main guide rod (6) is horizontally and slidably inserted into the large guide hole (26), and its inner end is fixedly connected to the center of the outer edge of the side pressure plate (3) through the variable cross section connector 2 (49); The pressure bearing end (7) is located on the outside of the same side long end fixing plate (41) and is fixedly connected to the outer end of the main guide rod (6); Two auxiliary guide rods (5) are symmetrically distributed on the upper and lower sides of the main guide rod (6) and are horizontally and slidably inserted into the two small guide holes (24); The manual turbine loading device includes two lateral reaction plates (46), two lateral reaction reinforcing rods (9), two manual turbine reducers (13), two flexible pressure plates (15), and two pressure sensors (12); the two lateral reaction plates (46) are distributed on the outside of the two long-end fixed plates (41); the lateral reaction plates (46) are I-shaped, with a sliding through hole (30) in the center, and multiple bolt holes I (32) are opened around the sliding through hole (30) in the middle part, and bolt holes G (31) are opened at the front and rear ends of the upper transverse arm, and bolt holes H (33) are opened at the front and rear ends of the lower transverse arm; the lateral reaction plates (46) are fixedly connected to the test platform base plate (23) by two connecting bolts D (22) passing through the two bolt holes H (33); the two lateral reaction reinforcing rods (9) are distributed in a front-to-back manner, and each lateral reaction reinforcing rod (9) has two Both ends are threaded sections, and both threaded sections pass through two bolt holes I (32) on the same side. At the same time, each threaded section is connected to two locking nuts (8) on both sides of the lateral reaction plate (46) by threaded engagement. Two manual worm gear reducers (13) are distributed on the outer side of the two lateral reaction plates (46). The manual worm gear reducers (13) are fixedly connected to the lateral reaction plates (46) by connecting bolts E (21) passing through multiple bolt holes I (32). At the same time, the worm (14) in the manual worm gear reducer (13) can slide into the inner side of the lateral reaction plate (46) through the sliding through hole (30). Two flexible pressure plates (15) are distributed on the outer side of the two lateral pressure transmission mechanisms (45) and are fixedly connected to the inner end of the worm (14) in the two manual worm gear reducers (13). Two pressure sensors (12) are connected to the inner side of the two flexible pressure plates (15). The vertical loading unit includes an upper pressure plate (47), a force transmission rod (1), and a variable cross-section connector (2). The width of the upper pressure plate (47) is adapted to the width of the sample receiving cavity, and its lower end is inserted into the side end of the sample receiving cavity and slides and seals with the two wide end fixing plates (42). At the same time, two water-stop rubber three (37) are embedded on the lower end of the upper pressure plate (47) along the front and rear sides. The force transmission rod (1) is vertically arranged, and its lower end is fixedly connected to the upper end of the upper pressure plate (47) through the variable cross-section connector (2). The permeation unit includes two glass plates (19); the two glass plates (19) are respectively fixedly installed in the rectangular windows of two wide-end fixed frames (44), wherein the front glass plate (19) has a water inlet hole (36) in the middle and the rear glass plate (19) has a water outlet hole (17) at the bottom.

2. The experimental apparatus for testing the relationship between damage and permeability changes in fractured rock mass according to claim 1, characterized in that, The base plate (23) of the test platform is a rectangular steel plate.

3. The experimental apparatus for testing the relationship between damage and permeability changes in fractured rock mass according to claim 1 or 2, characterized in that, The wide-end fixed frame (44) has multiple bolt holes J (38) around the rectangular window; the glass plate (19) is fixedly connected to the wide-end fixed frame (44) by multiple connecting bolts F (18) passing through the multiple bolt holes J (38).

4. The experimental apparatus for testing the relationship between damage and permeability changes in fractured rock mass according to claim 1 or 2, characterized in that, The test platform base plate (23), sample base frame (40), long end fixing plate (41), wide end fixing plate (42), side pressure plate (3), lateral reaction plate (46) and upper pressure plate (47) are all made of steel plate.

5. A test apparatus for testing the relationship between damage and permeability changes in fractured rock mass according to claim 1 or 2, characterized in that, The inner side of the glass plate (19) is provided with several vertical grooves evenly distributed along its length.

6. A test apparatus for testing the relationship between damage and permeability changes in fractured rock mass according to claim 1 or 2, characterized in that, It also includes a stabilizing pump and a flow meter. The inlet of the stabilizing pump is connected to the water tank through an inlet pipe, and its outlet is connected to the inlet hole (36) on the front glass plate (19) through a water supply pipe. A drain pipe is connected to the outer end of the outlet hole (17) on the rear glass plate (19), and the flow meter is connected in series on the drain pipe.

7. A test apparatus for testing the relationship between damage and permeability changes in fractured rock mass according to claim 1 or 2, characterized in that, It also includes a high-definition camera, which is mounted behind the rear glass panel (19).

8. The experimental apparatus for testing the relationship between damage and permeability changes in fractured rock mass according to claim 7, characterized in that, It also includes a controller, which is connected to a pressure sensor (12), a flow meter, a camera and a stabilizing pump.

9. The experimental apparatus for testing the relationship between damage and permeability changes in fractured rock mass according to claim 8, characterized in that, The controller is an industrial computer.

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