System and method for testing triaxial impact compression-shear seepage of multiphase rock

Abstract

The invention provides a multiphase rock triaxial impact compression-shear seepage test system and method, and belongs to the technical field of geotechnical engineering test equipment. Comprising an axial impact shearing device, a radial impact shearing device, a triaxial compression-shear seepage clamp holder and a movable impacted base, wherein the axial impact shearing device is rigidly connected with a fluid self-balancing chamber of the triaxial compression-shear seepage clamp holder through an axial impact force multiplier and is used for transmitting an axial load to a rock test piece in the triaxial compression-shear seepage clamp holder; the radial impact shearing device is connected with a lower cylinder barrel of the triaxial compression-shear seepage clamp holder through a radial impact force multiplier and is used for transmitting a radial load to a rock test piece in the triaxial compression-shear seepage clamp holder. Axial / radial static shear loading, impact shear loading and dynamic and static coupling shear loading under the triaxial condition can be applied to the rock test piece, and then impact of different medium seepage and different energy levels can be applied to the rock test piece according to different working conditions.

Description

Technical Field

[0001] This invention belongs to the technical field of geotechnical engineering testing equipment, and particularly relates to a triaxial impact shear flow testing system and method for multiphase rock. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] To ensure the safety of carbon sequestration project construction and reduce construction costs, impact-shear-seepage coupling tests under triaxial conditions can be conducted indoors to explore the mechanical and permeability characteristics of the rock mass, reveal the evolution law of rock mass impact-shear-seepage, and provide effective theoretical guidance for the project site.

[0004] However, existing methods or systems for impact compression-shear seepage testing generally have some technical problems, such as: (1) Patent application number 202310408264.X provides a test system for impact shear permeability of artificial crack specimens. This system can only perform triaxial impact shear loading on rock specimens and cannot achieve triaxial static shear loading or dynamic-static coupled shear loading. Moreover, its shear direction and seepage direction are the same, and the shear direction is singular, so it cannot perform impact shear seepage tests for working conditions where the seepage direction and shear direction are different. In addition, it cannot achieve impact force multiplication. If it is necessary to increase the impact shear force, the gas pressure in the gas storage chamber must be increased, which poses certain dangers during the test.

[0005] (2) The patent with application number 202011063973.1 provides a multi-functional multi-directional rock shear-seepage-temperature multi-field coupling test system. This system can only perform two-dimensional loading on rock specimens and cannot apply triaxial stress loads to rock specimens. Moreover, it can only realize static shear loading on specimens and cannot realize impact shear loading and dynamic-static coupling shear loading on specimens.

[0006] (3) Patent application number 201810223211.X provides a true triaxial rock shear seepage test device. This device can only perform static shear loading on rock specimens and cannot achieve impact shear loading and dynamic-static coupling shear loading on rock specimens. Moreover, it also has the problem that the shear direction and seepage direction are the same and the shear direction is singular, and it cannot perform impact shear seepage test for working conditions where the seepage direction and the shear direction are different. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention provides a triaxial impact shear flow test system and method for multiphase rocks, which can apply axial / radial static shear loading, impact shear loading and dynamic-static coupled shear loading under triaxial conditions to rock specimens, thereby enabling the application of different media flow and impact at different energy levels to rock specimens under different working conditions.

[0008] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions: The first aspect of this invention provides a triaxial impact shear flow testing system for multiphase rocks.

[0009] A triaxial impact shear flow testing system for multiphase rock includes: an axial impact shear device, a radial impact shear device, a triaxial impact shear flow holder, and a movable impact base; The axial impact shearing device is arranged above the movable support platform of the movable impact base, and is rigidly connected to the fluid self-balancing chamber of the triaxial compression shear seepage clamp through the guide bolt on the axial impact force multiplier. It is used to transfer axial load to the rock specimen in the triaxial compression shear seepage clamp. The radial impact shearing device is positioned above the bottom boss of the movable impact base and is connected to the lower cylinder of the triaxial compression shear seepage holder via the radial impact force multiplier piston near the rock specimen. It is used to transfer radial load to the rock specimen inside the triaxial compression shear seepage holder.

[0010] Furthermore, the axial impact shearing device includes: an axial impact force multiplier, an axial impact shearing piston, an axial impact guide piston, a first cylindrical guide rail, a first weight drop hammer, an acoustic emission probe, an axial shearing piston sealing cover, and a first guide piston sealing cover.

[0011] Furthermore, the axial impact force multiplier is cuboid in shape and has three cylindrical cavities inside: an axial shear piston cavity, an axial impact guide piston cavity, and an axial connecting cavity. The axial shear piston cavity and the axial impact guide piston cavity are arranged parallel and perpendicular to the rock specimen, respectively, and are connected through the axial connecting cavity. The axial connecting cavity contains hydraulic oil and is externally connected to a first single-cylinder constant speed and constant pressure pump.

[0012] Furthermore, the axial shear piston is coaxially assembled with the axial shear piston chamber and arranged parallel to the axial direction of the rock specimen; wherein, the end of the axial shear piston away from the rock specimen is in contact with hydraulic oil, and the end closer to the rock specimen is connected to the gas self-balancing chamber of the triaxial compression shear seepage clamp.

[0013] Furthermore, the axial impact guide piston is coaxially assembled with the axial impact guide piston cavity and is arranged perpendicular to the axial direction of the rock specimen; wherein, the end of the axial impact guide piston near the axial connecting cavity is in contact with hydraulic oil, and the end away from the axial connecting cavity is connected to the first cylindrical guide rail.

[0014] Furthermore, the radial impact shearing device includes: a radial impact force multiplier, a radial impact shearing piston, a radial impact guide piston, a second cylindrical guide rail, a second weight drop hammer, an acoustic emission probe, a radial shearing piston sealing cover, and a second guide piston sealing cover.

[0015] Furthermore, the radial impact force multiplier is cuboid in shape and has three cylindrical cavities inside: a radial shear piston cavity, a radial impact guide piston cavity, and a radial connecting cavity; wherein, the radial shear piston cavity and the radial impact guide piston cavity are connected through the radial connecting cavity; the radial connecting cavity contains hydraulic oil and is externally connected to a second single-cylinder constant speed and constant pressure pump.

[0016] Furthermore, the radial shear piston is coaxially assembled with the radial shear piston cavity and arranged radially parallel to the rock specimen; wherein, the end of the radial shear piston away from the rock specimen is in contact with hydraulic oil, and the end closer to the rock specimen is connected to the lower cylinder of the triaxial compression shear seepage clamp.

[0017] Furthermore, the radial impact guide piston is coaxially assembled with the radial impact guide piston cavity and arranged radially parallel to the rock specimen; wherein, the end of the radial impact guide piston near the radial connecting cavity is in contact with hydraulic oil, and the end away from the radial connecting cavity is connected to the second cylindrical guide rail.

[0018] The second aspect of this invention provides a method for testing triaxial impact shear flow in multiphase rocks.

[0019] A method for testing triaxial impact shear flow in multiphase rock, comprising: The rock specimen was placed in a triaxial compression-shear seepage holder and a triaxial confining pressure was applied. The loading mode is selected as follows: In axial static mode, the first single-cylinder constant speed and pressure pump is activated to apply an axial static load to the axial punching and shearing piston; in radial static mode, the second single-cylinder constant speed and pressure pump is activated to apply a radial static load to the radial punching and shearing piston; in axial impact mode, the first weight is released to impact the axial impact guide piston, and after hydraulic amplification, the rock specimen is subjected to axial impact shearing; in radial impact mode, the second weight is released to impact the radial impact guide piston, and after hydraulic amplification, the rock specimen is subjected to radial impact shearing; in dynamic-static coupling mode, impact disturbance is superimposed during static loading. Initiate the seepage test by injecting material into the rock specimen through the fluid self-equilibrium chamber to form seepage parallel or perpendicular to the shear direction; simultaneously monitor the impact force, displacement, acoustic emission, and seepage parameters to analyze the impact-shear-seepage coupling effect.

[0020] The above one or more technical solutions have the following beneficial effects: (1) This invention achieves multiple loading modes through the coordinated design of axial impact shearing device and radial impact shearing device: axial and radial static loads are applied by the first single-cylinder constant speed and pressure pump and the second single-cylinder constant speed and pressure pump respectively, and axial and radial impact shearing is achieved by releasing the first and second weights. Moreover, the impact disturbance can be superimposed during static loading to form a dynamic-static coupling mode, which solves the problem that the prior art can only perform triaxial impact shear loading and cannot achieve static and dynamic-static coupling shear loading. At the same time, liquid / gas is injected into the rock specimen through the fluid self-balancing chamber, which can form seepage parallel or perpendicular to the shear direction, breaking through the limitation that the shear direction and the seepage direction are single and the same. In addition, the diameter of the connecting cavity in the axial impact force multiplier and the radial impact force multiplier is smaller than the diameter of the impact shear piston cavity. The impact force is multiplied by the liquid pressure characteristics, and the impact shear force can be increased without increasing the gas pressure in the gas storage chamber, which reduces the experimental danger.

[0021] (2) The triaxial compression-shear seepage clamp of the present invention can apply triaxial confining pressure to the rock specimen. Combined with the axial load of the axial impact shear device and the radial load of the radial impact shear device, it can apply triaxial stress load to the specimen, overcoming the defect that the prior art can only perform two-dimensional loading. At the same time, through the design of static loading, impact loading and dynamic-static coupling loading modes, impact shear loading and dynamic-static coupling shear loading of the rock specimen can be realized, solving the problem that the prior art can only realize static shear loading.

[0022] (3) The present invention achieves impact shear by releasing a weight and dropping a hammer to impact the guide piston and amplifying it hydraulically. Impact disturbances can be superimposed in static loading, which can realize impact shear loading and dynamic-static coupling shear loading, solving the problem that only static shear loading can be performed in the prior art. At the same time, by utilizing the design of the fluid self-balancing chamber, it supports the formation of seepage parallel or perpendicular to the shear direction, breaking the limitation that the shear direction and seepage direction are single and the same in the prior art, and can carry out tests for different seepage and shear direction working conditions.

[0023] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0025] Figure 1 This is a schematic diagram of the main structure of a triaxial impact shear flow testing system for multiphase rock according to Embodiment 1 of the present invention.

[0026] Figure 2 This is a structural diagram of the seepage structure in Embodiment 1 of the present invention.

[0027] Figure 3 This is a cross-sectional view of the axial impact shearing device in Embodiment 1 of the present invention.

[0028] Figure 4 This is an overall structural diagram of the axial impact shearing device in Embodiment 1 of the present invention.

[0029] Figure 5 This is a cross-sectional view of the radial impact shearing device in Embodiment 1 of the present invention.

[0030] Figure 6 This is an overall structural diagram of the radial impact shearing device in Embodiment 1 of the present invention.

[0031] In the picture: Axial impact shearing device 1-1; Radial impact shearing device 1-2; Movable impact base 1-3; Triaxial shearing seepage clamp 1-4; Dual-cylinder constant speed and pressure pump 1-5; First single-cylinder constant speed and pressure pump 1-6A; Second single-cylinder constant speed and pressure pump 1-6B; Third single-cylinder constant speed and pressure pump 1-6C; First displacement sensor 1-7A; Second displacement sensor 1-7B; First pressure sensor 1-8A; Second pressure sensor 1-8B; Downstream standard chamber 1-9; Gas pressure sensor 1-10; Control valve 1-11; Gas source 1-12; Pressure reducing valve 1-13; Vacuum pump 1-14; Upstream standard chamber 1-15; Base pulley 1-16; Axial impact force multiplier 2-1; Axial shear piston sealing cover 2-2; Axial punching and shearing piston 2-3; Axial impact guide piston 2-4; First guide piston sealing cover 2-5; First weight drop hammer 2-6; First cylindrical guide rail 2-7; Axial punching and shearing piston cavity 2-8; Axial connecting cavity 2-9; Axial impact guide piston cavity 2-10. Radial impact force multiplier 3-1; Radial shear piston sealing cover 3-2; Radial punching and shearing piston 3-3; Second guide piston sealing cover 3-4; Radial impact guide piston 3-5; Radial punching and shearing piston cavity 3-6; Radial connecting cavity 3-7; Radial impact guide piston cavity 3-8. Detailed Implementation

[0032] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0033] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0034] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0035] Example 1 This embodiment discloses a triaxial impact shear flow testing system for multiphase rocks.

[0036] like Figure 1 As shown, a triaxial impact shear flow testing system for multiphase rock includes: an axial impact shear device, a radial impact shear device, a triaxial impact shear flow holder, and a movable impact base. The axial impact shearing device is arranged above the movable support platform of the movable impact base, and is rigidly connected to the fluid self-balancing chamber of the triaxial compression shear seepage clamp through the guide bolt on the axial impact force multiplier. It is used to transfer axial load to the rock specimen in the triaxial compression shear seepage clamp. The radial impact shearing device is positioned above the bottom boss of the movable impact base and is connected to the lower cylinder of the triaxial compression shear seepage holder via the radial impact force multiplier piston near the rock specimen. It is used to transfer radial load to the rock specimen inside the triaxial compression shear seepage holder.

[0037] Based on the above systematic design, this invention can apply triaxial axial / radial static shear loading, impact shear loading, and dynamic-static coupled shear loading to rock specimens, thereby enabling the application of different media seepage and impact levels to rock specimens under different working conditions. To facilitate understanding of the technical solution of this invention, the specific implementation methods are further explained and described below.

[0038] A triaxial impact shear flow test system for multiphase rock includes: an axial impact shear device 1-1, a radial impact shear device 1-2, a triaxial impact shear flow holder 1-4, and a movable impact base 1-3.

[0039] like Figure 4As shown, the axial impact shearing device includes: an axial impact force multiplier 2-1, an axial impact shearing piston 2-3, an axial impact guide piston 2-4, a first cylindrical guide rail 2-7, a first weight drop hammer 2-6, an acoustic emission probe, an axial shearing piston sealing cover 2-2, a first guide piston sealing cover 2-5, a first displacement sensor 1-7A, and a first pressure sensor 1-8A.

[0040] like Figure 3 As shown, the axial impact force multiplier 2-1 is cuboid in shape, containing an axial shear piston chamber 2-8, an axial impact guide piston chamber 2-10, and an axial connecting chamber 2-9, all three chambers being cylindrical cavities. The axial shear piston chamber 2-8 is arranged parallel to the axial direction of the rock specimen, while the axial impact guide piston chamber 2-10 is arranged perpendicular to the axial direction of the rock specimen. The two chambers are connected via the axial connecting chamber 2-9. Furthermore, the axial connecting chamber 2-9 contains hydraulic oil and is externally connected to a first single-cylinder constant-speed, constant-pressure pump 1-6A, which can provide axial static load.

[0041] The axial shear piston 2-3 is coaxially assembled with the axial shear piston chamber 2-8, parallel to the rock specimen and axially arranged; the end of the axial shear piston 2-3 away from the rock specimen is in contact with hydraulic oil and is driven by hydraulic pressure; the end closer to the rock specimen is connected to the piston in the gas self-balancing chamber, which is used to provide axial load for the rock specimen.

[0042] The axial impact guide piston 2-4 is coaxially assembled with the axial impact guide piston cavity 2-10, perpendicular to the rock specimen and axially arranged. The end of the axial impact guide piston 2-4 near the axial connecting cavity 2-9 is in contact with hydraulic oil, and the end away from the axial connecting cavity 2-9 is connected to the first cylindrical guide rail 2-7. The first weight hammer 2-6 impacts the outer platform in the first cylindrical guide rail 2-7, which drives the axial impact guide piston 2-4 to impact the hydraulic oil in the axial connecting cavity 2-9. The hydraulic oil impacts the axial shear piston 2-3, realizing the axial impact shearing of the rock specimen.

[0043] The first cylindrical guide rail 2-7 is connected to the axial impact guide piston 2-4 and is arranged perpendicular to the ground. Based on this, the first weight hammer 2-6 falls freely along the first cylindrical guide rail 2-7 to impact the impact-receiving platform in the first cylindrical guide rail 2-7, thereby achieving axial impact on the rock specimen.

[0044] The diameter of the axial connecting cavity 2-9 is smaller than that of the axial punching piston cavity 2-8. When the axial impact guide piston 2-4 impacts the hydraulic oil in the axial connecting cavity 2-9, the oil pressure in both the axial connecting cavity 2-9 and the axial punching piston cavity 2-8 rises simultaneously because the liquid pressure is equal everywhere. However, since the diameter of the axial punching piston cavity 2-8 is larger than that of the axial connecting cavity 2-9, the impact force acting on the rock specimen will be greater than the impact force of the axial impact guide piston on the hydraulic oil.

[0045] The first displacement sensor 1-7A and the first pressure sensor 1-8A are disposed in the axial connecting cavity 2-9. The first pressure sensor 1-8A is disposed perpendicular to the ground, with one end fixed to the axial impact force multiplier 2-1 and the other end fixed to the first cylindrical guide rail 2-7. It extends and retracts with the movement of the guide rail to measure the impact displacement. The first pressure sensor 1-8A is disposed in the axial connecting cavity 2-9 to collect the oil pressure changes in the cavity in real time.

[0046] An acoustic emission probe is located at the end of the axial shear piston 2-3, which can output and collect acoustic emission signals in real time during the impact shear seepage test. At the same time, the axial shear piston sealing cover 2-2 and the first guide piston sealing cover 2-5 are coaxially assembled with the axial shear piston and the axial impact guide piston, respectively, to achieve structural sealing.

[0047] like Figure 6 As shown, the radial impact shearing device includes: a radial impact force multiplier 3-1, a radial impact shearing piston 3-3, a radial impact guide piston 3-5, a second cylindrical guide rail, a second weight drop hammer, an acoustic emission probe, a radial shearing piston sealing cover 3-2, a second guide piston sealing cover 3-4, a second displacement sensor 1-7B, and a second pressure sensor 1-8B.

[0048] like Figure 5 As shown, the radial impact force multiplier 3-1 is rectangular in shape, containing a radial shear piston chamber 3-6, a radial impact guide piston chamber 3-8, and a radial connecting chamber 3-7, all three chambers being cylindrical cavities. The radial shear piston chamber 3-6 is arranged radially parallel to the rock specimen, and the radial impact guide piston chamber 3-8 is arranged parallel to the radial shear piston chamber 3-6. The two chambers are connected via the radial connecting chamber 3-7. The radial connecting chamber 3-7 contains hydraulic oil and is externally connected to a second single-cylinder constant-speed and constant-pressure pump 1-6B, which provides radial static load.

[0049] The radial shear piston 3-3 and the radial shear piston cavity 3-6 are coaxially assembled and arranged radially parallel to the specimen. The end of the radial shear piston 3-3 away from the rock specimen is in contact with hydraulic oil and is driven by hydraulic pressure. The end closer to the rock specimen is connected to the lower cylinder of the triaxial compression shear seepage clamp to provide radial shear load to the rock specimen.

[0050] The radial impact guide piston 3-5 and the radial impact guide piston cavity 3-8 are coaxially assembled and arranged radially parallel to the specimen. The end of the radial impact guide piston 3-5 near the radial connecting cavity 3-7 is in contact with hydraulic oil, and the end away from the radial connecting cavity 3-7 is connected to the second cylindrical guide rail. The second weight hammer impacts the outer platform in the second cylindrical guide rail, which drives the radial impact guide piston 3-5 to impact the hydraulic oil in the radial connecting cavity 3-7. The hydraulic oil impacts the radial shear piston, realizing the radial impact shearing of the specimen.

[0051] The diameter of the radial connecting cavity 3-7 is smaller than that of the radial shear piston cavity 3-6. When the radial impact guide piston 3-5 impacts the hydraulic oil in the radial connecting cavity 3-7, the oil pressure in both the radial connecting cavity 3-7 and the radial shear piston cavity 3-6 rises simultaneously because the liquid pressure is equal everywhere. However, since the diameter of the radial shear piston cavity 3-6 is larger than that of the radial connecting cavity 3-7, the impact force acting on the rock specimen will be greater than the impact force of the radial impact guide piston 3-5 on the hydraulic oil.

[0052] The second cylindrical guide rail is connected to the radial impact guide piston 3-5 and is arranged perpendicular to the ground. Based on this, the second weight hammer falls freely along the second cylindrical guide rail and impacts the impact-receiving platform in the second cylindrical guide rail, thereby achieving radial impact on the rock specimen.

[0053] The second displacement sensor 1-7B and the second pressure sensor 1-8B are disposed in the radial connecting cavity 3-7; wherein, the second displacement sensor 1-7B is used to collect the radial displacement of the punching and shearing piston in real time, and the second pressure sensor 1-8B is used to collect the oil pressure change in the cavity in real time.

[0054] An acoustic emission probe is located at the end of the radial shear piston 3-3, which can output and collect acoustic emission signals in real time during the impact shear seepage test. At the same time, the radial shear piston sealing cap 3-2 and the second guide piston sealing cap 3-4 are coaxially assembled with the radial shear piston 3-3 and the radial impact guide piston 3-5, respectively, to achieve structural sealing.

[0055] Furthermore, the triaxial compression-shear seepage clamp includes a fluid self-balancing chamber, a radial shear guide rail, a radial shear slider, an upper cylinder, a lower cylinder, connecting bolts, and guide bolts.

[0056] One end of the fluid self-balancing chamber is connected to the axial impact shearing device via guide bolts, and the other end is connected to the upper cylinder via connecting bolts. At the same time, the fluid self-balancing chamber is equipped with a self-balancing piston, and an air inlet is provided outside the self-balancing piston. The air inlet is connected to the gas channel provided at the piston shaft, which can be connected to an external air / water source to apply seepage to the rock specimen.

[0057] The upper cylinder is connected to the lower cylinder by connecting bolts. The upper cylinder is equipped with a radial shearing guide rail, and the lower cylinder slides along the radial shearing guide rail via a radial shearing slider to achieve radial shearing of the rock specimen. Both the upper and lower cylinders have cylindrical cavities inside, which together form the specimen confining pressure chamber.

[0058] Furthermore, the movable impact-bearing base 1-3 includes a movable support platform and a bottom boss. The upper part of the movable support platform is equipped with an axial impact shearing device 1-1 and a triaxial compression shear seepage clamp 1-4 for receiving the impact of the falling weight; the bottom boss is located at the bottom of the movable support platform for supporting the radial impact shearing device; and a base pulley 1-16 is installed below the movable impact-bearing base 1-3.

[0059] Example 2 This embodiment discloses a method for testing triaxial impact shear flow in multiphase rocks.

[0060] A method for testing triaxial impact shear flow in multiphase rock, comprising: Step S1: Place the rock specimen in the triaxial compression-shear seepage holder and apply triaxial confining pressure; Step S2: Select the loading mode. Specifically: In axial static mode, start the first single-cylinder constant speed and constant pressure pump to apply an axial static load to the axial shear piston; in radial static mode, start the second single-cylinder constant speed and constant pressure pump to apply a radial static load to the radial shear piston; in axial impact mode, release the first weight drop hammer to impact the axial impact guide piston, and after hydraulic amplification, perform axial impact shearing on the rock specimen; in radial impact mode, release the second weight drop hammer to impact the radial impact guide piston, and after hydraulic amplification, perform radial impact shearing on the rock specimen; in dynamic-static coupling mode, impact disturbance is superimposed during static loading. Step S3: Initiate the seepage test by injecting material into the rock specimen through the fluid self-equilibrium chamber to form seepage parallel or perpendicular to the shear direction; simultaneously monitor the impact force, displacement, acoustic emission, and seepage parameters to analyze the impact-shear-seepage coupling effect.

[0061] like Figure 2As shown, before executing steps S1-S3, it is necessary to connect the constant speed and pressure pumps (dual-cylinder constant speed and pressure pump 1-5, first single-cylinder constant speed and pressure pump 1-6A, second single-cylinder constant speed and pressure pump 1-6B, third single-cylinder constant speed and pressure pump 1-6C), gas cylinders, sensors (first displacement sensor 1-7A, second displacement sensor 1-7B, first pressure sensor 1-8A, second pressure sensor 1-8B, gas pressure sensor 1-10), upstream standard chamber 1-15, downstream standard chamber 1-9, pressure reducing valve 1-13, etc., through valves and pipelines. After completing the pipeline connection, the rubber sleeve and the specimen are placed in the specimen confining pressure chamber, the rock specimen is placed in the rubber sleeve, the control valve 1-11 is opened, the constant speed and pressure pump connected to the specimen confining pressure chamber is started, and confining pressure is applied to the rock specimen according to the test plan. It should be noted that the connection of these pipelines is not the main technical point of this invention, and this embodiment does not impose specific limitations on the specific connection method.

[0062] As an optional embodiment, according to the test plan, the control valve can be opened to start the first single-cylinder constant speed and constant pressure pump connected to the axial impact shearing device, apply axial pressure to the rock specimen, and monitor the axial pressure and axial displacement in real time through the first pressure sensor and the first displacement sensor.

[0063] As an optional embodiment, according to the test plan, the control valve can be opened to start the second single-cylinder constant speed and constant pressure pump connected to the radial impact shearing device, apply radial shear force to the rock specimen, and monitor the radial shear stress and radial shear displacement in real time through the second pressure sensor and the second displacement sensor.

[0064] As an optional embodiment, according to the test plan, vacuum pump 1-14 can be started to evacuate the gas pipeline. Then, the control valve is opened, and the gas source 1-12 in the gas cylinder is turned on to inject gas (CO2, He, etc.) into the pipeline. When the upstream and downstream gas pressures are equal, the control valve is closed to maintain equal upstream and downstream gas pressures. At this time, a constant-speed, constant-pressure pump is used to pressurize the gas. After pressurization is completed, the control valve is opened, which can generate a gas pressure pulse applied to the rock specimen. The permeability coefficient of the specimen is measured using the transient method through gas pressure sensor 1-10. Furthermore, during the seepage process on the rock specimen, a falling weight can be used to apply impact disturbance to the rock specimen. The falling weight impacts the impact-bearing outer platform on the cylindrical guide rail, driving the impact guide piston to impact the hydraulic oil in the connecting cavity. The hydraulic oil impacts the axial / radial shear piston, which can achieve impact shearing in different directions on the specimen during the seepage process.

[0065] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A triaxial impact shear flow testing system for multiphase rock, characterized in that, include: Axial impact shearing device, radial impact shearing device, triaxial compression shear seepage holder and mobile impact base; The axial impact shearing device is arranged above the movable support platform of the movable impact base, and is rigidly connected to the fluid self-balancing chamber of the triaxial compression shear seepage clamp through the guide bolt on the axial impact force multiplier. It is used to transfer axial load to the rock specimen in the triaxial compression shear seepage clamp. The radial impact shearing device is positioned above the bottom boss of the movable impact base and is connected to the lower cylinder of the triaxial compression shear seepage holder via the radial impact force multiplier piston near the rock specimen. It is used to transfer radial load to the rock specimen inside the triaxial compression shear seepage holder.

2. The triaxial impact shear flow testing system for multiphase rock as described in claim 1, characterized in that, The axial impact shearing device includes: an axial impact force multiplier, an axial impact shearing piston, an axial impact guide piston, a first cylindrical guide rail, a first weight drop hammer, an acoustic emission probe, an axial shearing piston sealing cover, and a first guide piston sealing cover.

3. The triaxial impact shear flow testing system for multiphase rock as described in claim 2, characterized in that, The axial impact force multiplier is rectangular and has three cylindrical cavities inside: an axial shear piston cavity, an axial impact guide piston cavity, and an axial connecting cavity. The axial shear piston cavity and the axial impact guide piston cavity are arranged parallel and perpendicular to the rock specimen, respectively, and are connected through the axial connecting cavity. The axial connecting cavity contains hydraulic oil and is externally connected to a first single-cylinder constant speed and constant pressure pump.

4. The triaxial impact shear flow testing system for multiphase rock as described in claim 2, characterized in that, The axial shear piston is coaxially assembled with the axial shear piston chamber and arranged parallel to the axial direction of the rock specimen; wherein, the end of the axial shear piston away from the rock specimen is in contact with hydraulic oil, and the end closer to the rock specimen is connected to the gas self-balancing chamber of the triaxial compression shear seepage clamp.

5. The triaxial impact shear flow testing system for multiphase rock as described in claim 2, characterized in that, The axial impact guide piston is coaxially assembled with the axial impact guide piston cavity and is arranged perpendicular to the axial direction of the rock specimen; wherein, the end of the axial impact guide piston near the axial connecting cavity is in contact with hydraulic oil, and the end away from the axial connecting cavity is connected to the first cylindrical guide rail.

6. The triaxial impact compression-shear seepage testing system for multiphase rock as described in claim 1, characterized in that, The radial impact shearing device includes: a radial impact force multiplier, a radial impact shearing piston, a radial impact guide piston, a second cylindrical guide rail, a second weight drop hammer, an acoustic emission probe, a radial shearing piston sealing cover, and a second guide piston sealing cover.

7. The triaxial impact compression-shear seepage testing system for multiphase rock as described in claim 6, characterized in that, The radial impact force multiplier is rectangular in shape and has three cylindrical cavities inside: a radial shear piston cavity, a radial impact guide piston cavity, and a radial connecting cavity. The radial shear piston cavity and the radial impact guide piston cavity are connected through the radial connecting cavity. The radial connecting cavity contains hydraulic oil and is externally connected to a second single-cylinder constant speed and constant pressure pump.

8. The triaxial impact shear flow testing system for multiphase rock as described in claim 6, characterized in that, The radial shear piston is coaxially assembled with the radial shear piston chamber and arranged radially parallel to the rock specimen; wherein, the end of the radial shear piston away from the rock specimen is in contact with hydraulic oil, and the end closer to the rock specimen is connected to the lower cylinder of the triaxial compression shear seepage clamp.

9. The triaxial impact compression-shear seepage testing system for multiphase rock as described in claim 6, characterized in that, The radial impact guide piston is coaxially assembled with the radial impact guide piston cavity and arranged radially parallel to the rock specimen; wherein, the end of the radial impact guide piston near the radial connecting cavity is in contact with hydraulic oil, and the end away from the radial connecting cavity is connected to the second cylindrical guide rail.

10. A method for testing triaxial impact shear flow in multiphase rock, characterized in that, include: The rock specimen was placed in a triaxial compression-shear seepage holder and a triaxial confining pressure was applied. The loading mode is selected as follows: In axial static mode, the first single-cylinder constant speed and pressure pump is activated to apply an axial static load to the axial punching and shearing piston; in radial static mode, the second single-cylinder constant speed and pressure pump is activated to apply a radial static load to the radial punching and shearing piston; in axial impact mode, the first weight is released to impact the axial impact guide piston, and after hydraulic amplification, the rock specimen is subjected to axial impact shearing; in radial impact mode, the second weight is released to impact the radial impact guide piston, and after hydraulic amplification, the rock specimen is subjected to radial impact shearing; in dynamic-static coupling mode, impact disturbance is superimposed during static loading. Initiate the seepage test by injecting material into the rock specimen through the fluid self-equilibrium chamber to form seepage parallel or perpendicular to the shear direction; simultaneously monitor the impact force, displacement, acoustic emission, and seepage parameters to analyze the impact-shear-seepage coupling effect.

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