A push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions

Abstract

A push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions includes a box body, a rock sample holder, a holder external transfer slide, and a holder external transfer slide; the holder external transfer slide is located outside the lifting pressure chamber, and the holder external transfer slide is located on the holder external transfer slide; the holder external transfer slide is provided with a holder internal transfer external guide rail; the box body is provided with a holder internal transfer internal guide rail and a holder internal transfer slide is provided above, and the rock sample holder is located on the holder internal transfer slide. The present invention adopts a horizontal push-pull method to achieve disassembly and assembly, and has the characteristics of low operating difficulty, low difficulty in controlling installation precision, and reduced safety accidents; it optimizes the high temperature and hydraulic fracturing application structure, and improves the efficiency of rock sample disassembly and assembly and the test efficiency; it can carry out indoor rock property measurement tests under the coupling of high temperature environment and dynamic disturbance, and can also carry out indoor rock crack extension characteristics measurement tests under the coupling of hydraulic fracturing and dynamic disturbance.

Description

Technical Field

[0001] The invention belongs to the technical field of true triaxial testing, and in particular relates to a push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions. Background Art

[0002] Rockbursts, as sudden geological hazards, can be categorized as spontaneous and dynamic disturbance-triggered. Field investigations have revealed that the vast majority of strong and extremely strong rockbursts are triggered by dynamic disturbances, particularly under high-temperature conditions. Currently, understanding rockburst mechanisms and stress release technologies is still relatively limited. Therefore, conducting true triaxial dynamic disturbance tests on hard rock under high-temperature and hydraulic fracturing conditions is crucial to understanding crack propagation patterns and fracture characteristics.

[0003] Conducting true triaxial dynamic perturbation tests on hard rock indoors under high-temperature and hydraulic fracturing conditions requires true triaxial testing equipment. Traditional true triaxial testing equipment often utilizes an integrated loading and unloading structure consisting of a reaction frame and pressure chamber. The specimen box requires a hoist for assembly and disassembly, which presents drawbacks such as operational difficulty, high precision control, and the potential for safety incidents. Furthermore, the complex structural design of traditional specimen boxes for high temperatures and hydraulic fracturing can affect the assembly and disassembly of rock specimens, thereby impacting overall testing efficiency. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides a push-pull hard rock true triaxial specimen box with high-temperature and hydraulic fracturing functions. The push-pull specimen box can be disassembled and assembled in a horizontal push-pull manner within the true triaxial testing equipment, and has the characteristics of low operating difficulty, low difficulty in controlling installation precision, and reduced safety accidents. The high-temperature and hydraulic fracturing application structure of the specimen box is optimized, thereby improving the disassembly and assembly efficiency of the rock specimens, thereby improving the overall testing efficiency. In conjunction with the true triaxial testing equipment, indoor rock property measurement tests under the coupling of high-temperature environment and dynamic disturbance can be carried out, and indoor rock crack propagation characteristics tests under the coupling of hydraulic fracturing and dynamic disturbance can also be carried out, providing theoretical guidance for actual deep engineering.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: a push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions, comprising a box body, a rock sample holder, a holder external transfer slide and a holder external transfer slide; the box body comprises a rectangular frame, a static closing plate and a dynamic closing plate; a static closing plate is fixedly installed at the upper end, lower end, left end, right end and front end of the rectangular frame, and the rectangular frame with the static closing plate is fixedly installed inside the lifting pressure chamber of the true triaxial testing machine; the holder external transfer slide is horizontally fixed outside the lifting pressure chamber, and the holder external transfer slide is arranged on the holder external transfer slide; An external guide rail for inner transfer of the clamper is fixed horizontally on the upper surface of the table; an internal guide rail for inner transfer of the clamper is fixed horizontally inside the rectangular frame, the internal guide rail for inner transfer of the clamper is parallel to the external guide rail for inner transfer of the clamper, and the internal guide rail for inner transfer of the clamper is located on the extension line of the external guide rail for inner transfer of the clamper; an internal transfer slide for the clamper is provided above the external guide rail for inner transfer of the clamper and the internal guide rail for inner transfer of the clamper, the rock sample clamper is placed on the upper surface of the internal transfer slide for the clamper, and a loading hole is opened at the center of the internal transfer slide for the clamper; the dynamic closing plate is vertically fixed on the upper surface of the internal transfer slide for the clamper, and the dynamic closing plate is assembled with the rear end of the rectangular frame to form a closed box body.

[0006] A loading hole is provided at the center of each static sealing plate, and a built-in force transmission column is provided in the central loading hole of each static sealing plate. Each built-in force transmission column is magnetically connected to the actuator piston rod on the same side of the true triaxial testing machine; a loading hole is also provided at the center of the dynamic sealing plate, and an external force transmission column is provided in the central loading hole of the dynamic sealing plate.

[0007] The rock sample holder includes a rock sample clamping assembly and a rock sample insulation frame; there are six sets of rock sample clamping assemblies, one set each at the upper end, lower end, left end, right end, front end, and rear end of the rock sample; the rock sample insulation frame is mounted on the outside of the rock sample and located between the six sets of rock sample clamping assemblies.

[0008] Rock sample deformation measuring sensors are provided between the rock sample clamping assembly at the upper end of the rock sample and the rock sample clamping assembly at the lower end of the rock sample, between the rock sample clamping assembly at the left end of the rock sample and the rock sample clamping assembly at the right end of the rock sample, and between the rock sample clamping assembly at the front end of the rock sample and the rock sample clamping assembly at the rear end of the rock sample.

[0009] The rock sample clamping assembly comprises a force transmission pad, a cooling pad and a heating pad; the heating pad is in contact with the rock sample; and the cooling pad is fixedly clamped between the force transmission pad and the heating pad.

[0010] A heating resistance wire and a temperature sensor are embedded in the heating pad block, and the heating resistance wire and the temperature sensor are electrically connected to the main control system of the true triaxial testing machine through wires.

[0011] A cooling water channel is embedded in the cooling pad. The cooling water channel is connected to a cooling water tank outside the true triaxial testing machine through a circulating water pipe. A circulating water pump is provided between the circulating water pipe and the cooling water tank.

[0012] A hydraulic fracturing hole is provided on the rock sample, a hydraulic fracturing pipe is inserted into the hydraulic fracturing hole, the hydraulic fracturing pipe seal passes through a force transmission pad, a cooling pad and a heating pad and extends into the hydraulic fracturing hole, the hydraulic fracturing pipe is connected to a hydraulic fracturing pump outside the true triaxial testing machine, and the hydraulic fracturing pump is connected to a water source.

[0013] Beneficial effects of the present invention:

[0014] The push-pull hard rock true triaxial specimen box of the present invention, which has high-temperature and hydraulic fracturing functions, can be disassembled and assembled in a horizontal push-pull manner within the true triaxial testing equipment, and has the characteristics of low operating difficulty, low difficulty in controlling installation precision, and reduced safety accidents. The high-temperature and hydraulic fracturing application structure of the specimen box is optimized, thereby improving the disassembly and assembly efficiency of the rock specimens, thereby improving the overall testing efficiency. In conjunction with the true triaxial testing equipment, indoor rock property measurement tests under the coupling of high-temperature environment and dynamic disturbance can be carried out, and indoor rock crack extension characteristics measurements under the coupling of hydraulic fracturing and dynamic disturbance can also be carried out, providing theoretical guidance for actual deep engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic structural diagram of a push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions according to the present invention;

[0016] Figure 2 Schematic diagram of the structure of the rock sample holder, internal force transmission column and external force transmission column of the present invention (the rock sample insulation frame is not shown);

[0017] Figure 3 Schematic diagram of the structure of the rock sample holder of the present invention (overall);

[0018] Figure 4 Schematic diagram of the structure of the rock sample holder of the present invention (cross-sectional view);

[0019] Figure 5 This is a schematic diagram of the push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions of the present invention when used in conjunction with a true triaxial testing machine.

[0020] In the figure, 1 is a box body, 2 is a rock sample holder, 3 is a slide for transferring the sample outside the holder, 4 is a slide rail for transferring the sample outside the holder, 5 is a rectangular frame, 6 is a static sealing plate, 7 is a dynamic sealing plate, 8 is a true triaxial testing machine, 9 is a lifting pressure chamber, 10 is an external guide rail for transferring the sample inside the holder, 11 is a built-in guide rail for transferring the sample inside the holder, 12 is a slide for transferring the sample inside the holder, 13 is a built-in force transmission column, 14 is an external force transmission column, 15 is a rock sample holding assembly, 16 is a rock sample insulation frame, 17 is a rock sample, 18 is a rock sample deformation measurement sensor, 19 is a force transmission pad, 20 is a cooling pad, 21 is a heating pad, 22 is a heating resistor, 23 is a temperature sensor, 24 is a cooling water channel, 25 is a hydraulic fracturing hole, and 26 is a hydraulic fracturing pipe. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figures 1 to 5 As shown, a push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions includes a box body 1, a rock sample holder 2, a holder external transfer slide 3 and a holder external transfer slide rail 4; the box body 1 includes a rectangular frame 5, a static sealing plate 6 and a dynamic sealing plate 7; a static sealing plate 6 is fixedly installed at the upper end, lower end, left end, right end and front end of the rectangular frame 5, and the rectangular frame 5 with the static sealing plate 6 is fixedly installed inside the lifting pressure chamber 9 of the true triaxial testing machine 8; the holder external transfer slide rail 4 is horizontally fixed outside the lifting pressure chamber 9, and the holder external transfer slide 3 is arranged on the holder external transfer slide rail 4; the upper surface of the holder external transfer slide 3 is horizontally fixed with a holder internal transfer slide The external transport guide rail 10 is provided; the internal transfer guide rail 11 of the clamper is fixed horizontally inside the rectangular frame 5, the internal transfer guide rail 11 of the clamper is parallel to the external transfer slide rail 4 of the clamper, and the internal transfer guide rail 11 of the clamper is located on the extension line of the external transfer guide rail 10 of the clamper; the internal transfer slide 12 of the clamper is provided above the external transfer guide rail 10 of the clamper and the internal transfer guide rail 11 of the clamper, the rock sample clamper 2 is placed on the upper surface of the internal transfer slide 12 of the clamper, and a loading hole is opened at the center of the internal transfer slide 12 of the clamper; the dynamic closing plate 7 is fixed vertically on the upper surface of the internal transfer slide 12 of the clamper, and the dynamic closing plate 7 is assembled with the rear end of the rectangular frame 5 to form a closed box body 1.

[0023] A loading hole is provided at the center of each static sealing plate 6, and a built-in force transmission column 13 is provided in the central loading hole of each static sealing plate 6. Each built-in force transmission column 13 is magnetically connected to the actuator piston rod on the same side of the true triaxial testing machine 8; a loading hole is also provided at the center of the dynamic sealing plate 7, and an external force transmission column 14 is provided in the central loading hole of the dynamic sealing plate 7.

[0024] The rock sample holder 2 includes a rock sample clamping assembly 15 and a rock sample insulation frame 16; the rock sample clamping assembly 15 is in six sets, with one set each at the upper end, lower end, left end, right end, front end, and rear end of the rock sample 17; the rock sample insulation frame 16 is sleeved on the outside of the rock sample 17 and located between the six sets of rock sample clamping assemblies 15.

[0025] Rock sample deformation measuring sensors 18 are provided between the rock sample clamping assembly 15 at the upper end of the rock sample 17 and the rock sample clamping assembly 15 at the lower end of the rock sample 17, between the rock sample clamping assembly 15 at the left end of the rock sample 17 and the rock sample clamping assembly 15 at the right end of the rock sample 17, and between the rock sample clamping assembly 15 at the front end of the rock sample 17 and the rock sample clamping assembly 15 at the rear end of the rock sample 17.

[0026] The rock sample clamping assembly 15 includes a force transmission pad 19 , a cooling pad 20 and a heating pad 21 ; the heating pad 21 is in contact with the rock sample 17 ; and the cooling pad 20 is fixedly clamped between the force transmission pad 19 and the heating pad 21 .

[0027] A heating resistor 22 and a temperature sensor 23 are embedded in the heating pad 21 . The heating resistor 22 and the temperature sensor 23 are electrically connected to the main control system of the true triaxial testing machine 8 through wires.

[0028] A cooling water channel 24 is embedded in the cooling pad 20 . The cooling water channel 24 is connected to a cooling water tank outside the true triaxial testing machine 8 through a circulating water pipe. A circulating water pump is provided between the circulating water pipe and the cooling water tank.

[0029] A hydraulic fracturing hole 25 is provided on the rock sample 17, and a hydraulic fracturing pipe 26 is inserted into the hydraulic fracturing hole 25. The hydraulic fracturing pipe 26 seals and passes through the force transmission pad 19, the cooling pad 20 and the heating pad 21 to extend into the hydraulic fracturing hole 25. The hydraulic fracturing pipe 26 is connected to the hydraulic fracturing pump outside the true triaxial testing machine 8, and the hydraulic fracturing pump is connected to a water source.

[0030] The following describes a one-time use process of the present invention in conjunction with the accompanying drawings:

[0031] In this embodiment, the box body 1 is in a disassembled state when stored, which can save space and can be assembled when used; the clamper external transfer slide 3, the clamper external transfer slide rail 4, the clamper internal transfer external guide rail 10, the clamper internal transfer built-in guide rail 11, and the clamper internal transfer slide 12 are all in the state of parts when stored, and are only installed on the true triaxial testing machine 8 when in use, which can ensure that the true triaxial testing machine 8 can carry out true triaxial testing under normal conditions.

[0032] Before the test, the prepared rock sample 17 is first clamped into the rock sample holder 2, and then the rock sample holder 2 with the rock sample 17 is placed on the center of the upper surface of the transfer slide 12 in the holder, and then the transfer slide 3 outside the holder is pushed along the transfer slide rail 4 outside the holder until the external guide rail 10 of the transfer inside the holder is docked with the internal guide rail 11 of the transfer inside the holder, and then the transfer slide 12 inside the holder is pushed until the transfer slide 12 inside the holder moves from the external guide rail 10 of the transfer inside the holder to the internal guide rail 11 of the transfer inside the holder, and finally the rock sample holder 2 is transferred into the box body 1. At this time, the movable closing plate 7 is buckled with the rectangular frame 5 to realize the closure of the box body 1.

[0033] When the box body 1 is closed, the wires of the heating resistance wire 22 and the temperature sensor 23 are connected to the main control system through the control interface inside the lifting pressure chamber 9 of the true triaxial testing machine 8, the circulating water pipe is connected to the cooling water tank and the circulating water pump through the water channel interface inside the lifting pressure chamber 9 of the true triaxial testing machine 8, and the hydraulic fracturing pipe 26 is connected to the hydraulic fracturing pump through the hydraulic fracturing interface inside the lifting pressure chamber 9 of the true triaxial testing machine 8.

[0034] When all the above preparations are completed, the lifting pressure chamber 9 is controlled to drop into the main reaction force frame of the true triaxial testing machine 8, and then the six actuators of the true triaxial testing machine 8 are controlled to center and pre-clamp the rock sample holder 2.

[0035] When conducting an indoor test to measure rock properties in a high-temperature environment coupled with dynamic perturbations, the heating resistor 22 is first activated, heating the rock sample 17 via the heating pad 21. During this heating process, the temperature is measured in real time via the temperature sensor 23 until the rock sample 17 reaches the set value. Simultaneously, the circulating water pump is activated to circulate cooling water between the cooling water tank, the circulating water pipe, and the cooling water path 24, ensuring that the high temperature of the heating pad 21 is not transmitted outward. Furthermore, the rock sample 17 is insulated and heat-insulated by the rock sample insulation frame 16 to simulate a high-temperature environment. Once the high-temperature environment simulation is complete, true triaxial stress is applied to the rock sample 17 in the rock sample holder 2 via the six actuators of the true triaxial testing machine 8. The true triaxial stress is gradually increased to a preset value. Dynamic perturbations are then applied at the preset true triaxial stress value, while the stress-strain curve of the rock sample 17 is simultaneously acquired until the rock sample 17 fails.

[0036] When conducting an indoor test to measure rock crack growth characteristics under the coupling of hydraulic fracturing and dynamic perturbation, the hydraulic fracturing pump is first activated, injecting high-pressure water into the hydraulic fracturing holes 25 of the rock sample 17 through the hydraulic fracturing pipe 26. The pressure of the high-pressure water causes micro-cracks to form within the rock sample 17, simulating a hydraulic fracturing state. After the hydraulic fracturing state simulation is completed, the six actuators of the true triaxial testing machine 8 apply true triaxial stress to the rock sample 17 in the rock sample holder 2. The true triaxial stress is gradually increased to a preset value. Then, dynamic perturbation is applied at the preset true triaxial stress value, and the stress-strain curve of the rock sample 17 is simultaneously obtained until the rock sample 17 fails.

[0037] The solutions in the embodiments are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications that do not depart from the scope of protection of the present invention are included in the scope of protection of the present invention.

Claims

1. A push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions, characterized by: The box body comprises a box body, a rock sample holder, a holder external transfer slide and a holder external transfer slide rail; the box body comprises a rectangular frame, a static closing plate and a dynamic closing plate; a static closing plate is fixedly installed at the upper end, lower end, left end, right end and front end of the rectangular frame, and the rectangular frame with the static closing plate is fixedly installed inside the lifting pressure chamber of the true triaxial testing machine; the holder external transfer slide rail is horizontally fixed to the outside of the lifting pressure chamber, and the holder external transfer slide is arranged on the holder external transfer slide rail; the upper surface of the holder external transfer slide rail is horizontally fixed with a holder internal transfer external guide rail; the inside of the rectangular frame is horizontally fixed with a holder internal transfer internal guide rail, The built-in guide rail for transporting within the holder is parallel to the slide rail for transporting outside the clamper, and the built-in guide rail for transporting within the clamper is located on the extension line of the external guide rail for transporting within the clamper; an internal transfer slide for the clamper is provided above the external guide rail for transporting within the clamper and the built-in guide rail for transporting within the clamper, and the rock sample clamper is placed on the upper surface of the slide for transporting within the clamper, and a loading hole is provided at the center of the slide for transporting within the clamper; the dynamic closing plate is vertically fixed on the upper surface of the slide for transporting within the clamper, and the dynamic closing plate and the rear end of the rectangular frame are assembled to form a closed box body; a loading hole is provided in the center of each of the static closing plates, and a built-in force transmission column is provided in the central loading hole of each static closing plate, Each built-in force transmission column is magnetically connected to the actuator piston rod on the same side of the true triaxial testing machine; a loading hole is also provided in the center of the dynamic closing plate, and an external force transmission column is provided in the central loading hole of the dynamic closing plate; the rock sample holder includes a rock sample clamping assembly and a rock sample insulation frame; the rock sample clamping assembly is in six sets, with one set each at the upper end, lower end, left end, right end, front end and rear end of the rock sample; the rock sample insulation frame is mounted on the outside of the rock sample and is located between the six sets of rock sample clamping assemblies; between the rock sample clamping assembly at the upper end of the rock sample and the rock sample clamping assembly at the lower end of the rock sample, and between the rock sample clamping assembly at the left end of the rock sample and the rock sample Rock sample deformation measuring sensors are provided between the rock sample clamping assemblies at the right end of the sample and between the rock sample clamping assemblies at the front end of the rock sample and the rock sample clamping assemblies at the rear end of the rock sample; the rock sample clamping assemblies include a force transmission pad, a cooling pad and a heating pad; the heating pad is in contact with the rock sample; the cooling pad is fixedly clamped between the force transmission pad and the heating pad; a hydraulic fracturing hole is provided on the rock sample, a hydraulic fracturing pipe is inserted into the hydraulic fracturing hole, the hydraulic fracturing pipe seal passes through the force transmission pad, the cooling pad and the heating pad and extends into the hydraulic fracturing hole, the hydraulic fracturing pipe is connected to the hydraulic fracturing pump outside the true triaxial testing machine, and the hydraulic fracturing pump is connected to a water source.

2. The push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions according to claim 1, characterized in that: A heating resistance wire and a temperature sensor are embedded in the heating pad block, and the heating resistance wire and the temperature sensor are electrically connected to the main control system of the true triaxial testing machine through wires.

3. The push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions according to claim 1, characterized in that: A cooling water channel is embedded in the cooling pad. The cooling water channel is connected to a cooling water tank outside the true triaxial testing machine through a circulating water pipe. A circulating water pump is provided between the circulating water pipe and the cooling water tank.

Images