Push-pull true triaxial hard-rock sample chamber with high-temperature and hydraulic fracturing functions

Abstract

A push-pull true triaxial hard-rock sample chamber with high-temperature and hydraulic fracturing functions. The sample chamber comprises a body (1), a rock sample holder (2), a holder outward transfer slide table (3), and holder outward transfer slide rails (4), wherein the holder outward transfer slide rails (4) are located outside a lifting pressure compartment (9), and the holder outward transfer slide table (3) is located on the holder outward transfer slide rails (4); external holder inward transfer guide rails (10) are provided on the holder outward transfer slide table (3); internal holder inward transfer guide rails (11) are provided inside the body (1), and a holder inward transfer slide table (12) is provided above the internal holder inward transfer guide rails (11); and the rock sample holder (2) is located on the holder inward transfer slide table (12). The push-pull true triaxial hard-rock sample chamber with high-temperature and hydraulic fracturing functions can be removed from and installed inside a true-triaxial test apparatus by means of horizontal pushing and pulling, and has the characteristics of low operation difficulty, low difficulty in terms of control over installation accuracy, reduced risk of safety accidents, etc. The structures for applying a high temperature and hydraulic fracturing are optimized, improving the removal and installation efficiency and test efficiency of a rock sample. The sample chamber enables both an indoor test for rock properties under coupled high-temperature environment and dynamic disturbance, and an indoor test for rock crack propagation characteristics under coupled hydraulic fracturing effect and dynamic disturbance.

Description

Push-pull type hard rock true triaxial sample box with high temperature and hydraulic fracturing functions TECHNICAL FIELD

[0001] The present application belongs to the technical field of true triaxial test, in particular relates to a push-pull type hard rock true triaxial sample box with high temperature and hydraulic fracturing functions. BACKGROUND

[0002] Rock burst as a sudden geological disaster can be divided into spontaneous rock burst and dynamic disturbance triggered rock burst according to the occurrence mechanism. Through field investigation, it is found that most of the strong and extremely strong rock bursts are triggered by dynamic disturbance, especially under high temperature conditions. At present, the rock burst mechanism and stress release technology are still relatively lacking. Therefore, in order to obtain the crack propagation law and fracture characteristics of rock, it is of great significance to carry out hard rock true triaxial dynamic disturbance test under high temperature and hydraulic fracturing conditions.

[0003] In order to carry out hard rock true triaxial dynamic disturbance test under high temperature and hydraulic fracturing conditions in the laboratory, it is necessary to rely on true triaxial test equipment. The traditional true triaxial test equipment adopts the integrated loading and unloading structure of reaction frame and pressure chamber, and the disassembly of the sample box needs to be carried out by lifting, which has the disadvantages of high operation difficulty, high installation precision control difficulty, easy to cause safety accidents and the like. In addition, the traditional sample box has a complex design of high temperature and hydraulic fracturing application structure, which also affects the disassembly efficiency of the rock sample, thereby affecting the overall test efficiency.

[0004] SUMMARY

[0005] In view of the problems existing in the prior art, the present application provides a push-pull type hard rock true triaxial sample box with high temperature and hydraulic fracturing functions, which can be disassembled and assembled in a horizontal push-pull manner in the true triaxial test equipment, has the characteristics of small operation difficulty, low installation precision control difficulty and reduction of safety accidents, optimizes the high temperature and hydraulic fracturing application structure of the sample box, improves the disassembly efficiency of the rock sample, and further improves the overall test efficiency; in cooperation with the true triaxial test equipment, it can carry out indoor rock property test under the coupling of high temperature environment and dynamic disturbance, and can also carry out indoor rock crack propagation characteristic test under the coupling of hydraulic fracturing and dynamic disturbance, which provides theoretical guidance for actual deep engineering.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a push-pull type true triaxial sample box for hard rock with high temperature and hydraulic fracturing functions, comprising a box body, a rock sample holder, an external transfer slide of the holder, and an external transfer rail of the holder; the box body comprises a rectangular frame, a static sealing plate, and a dynamic sealing plate; a static sealing 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 sealing plates is fixedly installed inside the lifting pressure chamber of the true triaxial testing machine; the external transfer rail of the holder is horizontally fixed outside the lifting pressure chamber, and the external transfer slide of the holder is set on the external transfer rail of the holder; the external transfer rail of the holder is horizontally fixed outside the lifting pressure chamber, and the external transfer slide of the holder is set on the external transfer rail of the holder; An external guide rail for internal transfer of the clamp is horizontally fixed on the surface of the platform; an internal guide rail for internal transfer of the clamp is horizontally fixed inside the rectangular frame, parallel to the external guide rail for internal transfer of the clamp, and located on the extension line of the external guide rail for internal transfer of the clamp; an internal transfer slide is provided above the external guide rail and the internal transfer slide, and the rock sample clamp is placed on the upper surface of the internal transfer slide, with a loading hole at the center of the internal transfer slide; a movable sealing plate is vertically fixed on the upper surface of the internal transfer slide, and the movable sealing plate is joined with the rear end of the rectangular frame to form a closed box.

[0007] A loading hole is provided in the center of each static sealing plate, and a built-in force transmission column is provided in the 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 in the center of each dynamic sealing plate, and an external force transmission column is provided in the loading hole of each dynamic sealing plate.

[0008] The rock sample holder includes a rock sample holding assembly and a rock sample insulation frame; there are six sets of rock sample holding assemblies, one set each at the top, bottom, left, right, front, and rear ends of the rock sample; the rock sample insulation frame is fitted onto the outside of the rock sample and located between the six sets of rock sample holding assemblies.

[0009] Rock sample deformation measurement sensors are installed between the rock sample clamping assembly at the upper end and the rock sample clamping assembly at the lower end of the rock sample, between the rock sample clamping assembly at the left end 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 and the rock sample clamping assembly at the rear end of the rock sample.

[0010] The rock sample clamping assembly includes 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.

[0011] The heating resistance wire and the temperature sensor are embedded in the heating pad block, and the heating resistance wire and the temperature sensor are electrically connected with the main control system of the true triaxial testing machine through wires respectively.

[0012] The cooling water path is embedded in the cooling pad block, and the cooling water path is communicated with the cooling water tank outside the true triaxial testing machine through a circulating water pipe.

[0013] The hydraulic fracturing hole is provided on the rock sample, the hydraulic fracturing pipe is inserted into the hydraulic fracturing hole, the hydraulic fracturing pipe is sealed and extends into the hydraulic fracturing hole through the force transmission pad, the cooling pad and the heating pad, the hydraulic fracturing pipe is connected with the hydraulic fracturing pump outside the true triaxial testing machine, and the hydraulic fracturing pump is connected with the water source.

[0014] The beneficial effects of the present application are as follows:

[0015] The push-pull type hard rock true triaxial sample box with high temperature and hydraulic fracturing function has the characteristics of small operation difficulty, low installation precision control difficulty and reduced safety accidents, and can be disassembled and assembled in a horizontal push-pull manner in the true triaxial testing equipment; the application optimizes the high temperature and hydraulic fracturing application structure of the sample box, improves the disassembly and assembly efficiency of the rock sample, and further improves the overall test efficiency; in cooperation with the true triaxial testing equipment, the rock property indoor test under the coupling of high temperature environment and dynamic disturbance can be carried out, and the rock crack propagation characteristic indoor test under the coupling of hydraulic fracturing effect and dynamic disturbance can also be carried out, thereby providing theoretical guidance for actual deep engineering. BRIEF DESCRIPTION OF DRAWINGS

[0016] Fig. 1 is a structural schematic view of the push-pull type hard rock true triaxial sample box with high temperature and hydraulic fracturing function;

[0017] Fig. 2 is a structural schematic view of the rock sample holder, the built-in force transmission column and the external force transmission column (the rock sample heat preservation frame is not shown);

[0018] Fig. 3 is a structural schematic view of the rock sample holder (as a whole);

[0019] Fig. 4 is a structural schematic view of the rock sample holder (cross section);

[0020] Fig. 5 is a schematic view of the push-pull type hard rock true triaxial sample box with high temperature and hydraulic fracturing function when used in cooperation with the true triaxial testing machine.

[0021] 1-box body, 2-rock sample holder, 3-outer transfer sliding table of holder, 4-outer transfer sliding rail of holder, 5-rectangular frame, 6-static sealing plate, 7-dynamic sealing plate, 8-true triaxial testing machine, 9-lifting pressure chamber, 10-outer guide rail of inner transfer of holder, 11-inner guide rail of inner transfer of holder, 12-inner transfer sliding table of holder, 13-inner force transmission column, 14-outer force transmission column, 15-rock sample holding assembly, 16-rock sample heat preservation frame, 17-rock sample, 18-rock sample deformation measurement sensor, 19-force transmission cushion block, 20-cooling cushion block, 21-heating cushion block, 22-heating resistance wire, 23-temperature sensor, 24-cooling waterway, 25-hydraulic fracturing hole, 26-hydraulic fracturing pipe. DETAILED DESCRIPTION

[0022] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0023] As shown in FIGS. 1-5, a push-pull type hard rock true triaxial sample box with high temperature and hydraulic fracturing functions comprises a box body 1, a rock sample holder 2, an outer transfer sliding table 3 of holder and an outer transfer sliding rail 4 of holder; the box body 1 comprises a rectangular frame 5, static sealing plates 6 and a dynamic sealing plate 7; one static sealing plate 6 is fixedly installed at each of the upper end, lower end, left end, right end and front end of the rectangular frame 5, and the rectangular frame 5 on which the static sealing plates 6 are installed is fixedly installed inside a lifting pressure chamber 9 of a true triaxial testing machine 8; the outer transfer sliding rail 4 of holder is horizontally fixed outside the lifting pressure chamber 9, and the outer transfer sliding table 3 of holder is arranged on the outer transfer sliding rail 4 of holder; an outer guide rail 10 of inner transfer of holder is horizontally fixed on the upper surface of the outer transfer sliding table 3 of holder; an inner guide rail 11 of inner transfer of holder is horizontally fixed inside the rectangular frame 5, and the inner guide rail 11 of inner transfer of holder is parallel to the outer transfer sliding rail 4 of holder and located on the extension line of the outer guide rail 10 of inner transfer of holder; an inner transfer sliding table 12 of holder is arranged above the outer guide rail 10 of inner transfer of holder and the inner guide rail 11 of inner transfer of holder, the rock sample holder 2 is placed on the upper surface of the inner transfer sliding table 12 of holder, and a loading hole is formed at the center of the inner transfer sliding table 12 of holder; the dynamic sealing plate 7 is vertically fixed on the upper surface of the inner transfer sliding table 12 of holder, and the dynamic sealing plate 7 and the rear end of the rectangular frame 5 are combined to form a closed box body 1.

[0024] A loading hole is formed at the center of each of the static sealing plates 6, and an inner force transmission column 13 is arranged in each of the center loading holes of the static sealing plates 6, and each inner force transmission column 13 is connected to the actuator piston rod on the same side of the true triaxial testing machine 8 by magnetic attraction; a loading hole is also formed at the center of the dynamic sealing plate 7, and an outer force transmission column 14 is arranged in the center loading hole of the dynamic sealing plate 7.

[0025] The rock sample holder 2 comprises a rock sample clamping assembly 15 and a rock sample heat preservation frame 16; the rock sample clamping assembly 15 is six sets, and is arranged at the upper end, lower end, left end, right end, front end and rear end of the rock sample 17; the rock sample heat preservation frame 16 is sleeved outside the rock sample 17 and between the six sets of rock sample clamping assemblies 15.

[0026] 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, 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 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 are all provided with a rock sample deformation measuring sensor 18.

[0027] The rock sample clamping assembly 15 comprises a force transmission pad 19, a cooling pad 20 and a heating pad 21; the heating pad 21 is in abutting contact with the rock sample 17; the cooling pad 20 is fixedly clamped between the force transmission pad 19 and the heating pad 21.

[0028] The heating resistance wire 22 and the temperature sensor 23 are embedded in the heating pad 21, and the heating resistance wire 22 and the temperature sensor 23 are respectively electrically connected to the main control system of the true triaxial testing machine 8 through wires.

[0029] The cooling water channel 24 is embedded in the cooling pad 20, and the cooling water channel 24 is communicated with a cooling water tank outside the true triaxial testing machine 8 through a circulating water pipe, and a circulating water pump is arranged between the circulating water pipe and the cooling water tank.

[0030] The hydraulic fracturing hole 25 is arranged on the rock sample 17, the hydraulic fracturing pipe 26 is inserted into the hydraulic fracturing hole 25, the hydraulic fracturing pipe 26 is sealed and penetrates through the force transmission pad 19, the cooling pad 20 and the heating pad 21 and extends into the hydraulic fracturing hole 25, the hydraulic fracturing pipe 26 is connected with a hydraulic fracturing pump outside the true triaxial testing machine 8, and the hydraulic fracturing pump is connected with a water source.

[0031] The following describes the one-time use process of the present application in combination with the drawings:

[0032] In the embodiment, the box body 1 is in a disassembled state when stored, so that space can be saved, and the box body 1 is assembled when used; the outer transfer sliding table 3 of the holder, the outer transfer sliding rail 4 of the holder, the outer guide rail 10 of the inner transfer of the holder, the inner guide rail 11 of the inner transfer of the holder, and the inner transfer sliding table 12 of the holder are all in a part state when stored, and are only mounted on the true triaxial testing machine 8 when used, so that the true triaxial testing machine 8 can carry out true triaxial tests in a normal state.

[0033] Before the test, the prepared rock sample 17 is clamped into the rock sample holder 2, and then the rock sample holder 2 clamped with the rock sample 17 is placed on the center of the upper surface of the inner transfer sliding table 12 of the holder outer transfer sliding rail 4, and then the holder outer transfer sliding table 3 is pushed along the holder outer transfer sliding rail 4 until the holder inner transfer outer guide rail 10 and the holder inner transfer inner guide rail 11 are connected together, and then the holder inner transfer sliding table 12 is pushed until the holder inner transfer sliding table 12 moves from the holder inner transfer outer guide rail 10 to the holder inner transfer inner guide rail 11, 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 closing of the box body 1.

[0034] 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 waterway 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.

[0035] When the above preparation work is completed, the lifting pressure chamber 9 is controlled to fall into the main counterforce 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.

[0036] When the rock property indoor test under the coupling of high temperature environment and dynamic disturbance needs to be carried out, the heating resistance wire 22 is started first, the rock sample 17 is heated through the heating pad 21, the temperature is measured in real time through the temperature sensor 23 during the heating process, until the temperature of the rock sample 17 reaches the set value. At the same time, the circulating water pump is started, the cooling water is circulated between the cooling water tank, the circulating water pipe and the cooling waterway 24, to ensure that the high temperature of the heating pad 21 is not conducted outward, and the rock sample 17 is heat-insulated by the rock sample heat-insulating frame 16, to simulate the high temperature environment. When the high temperature environment simulation is completed, the rock sample 17 in the rock sample holder 2 is subjected to true triaxial stress by the six actuators of the true triaxial testing machine 8, the true triaxial stress is increased step by step until the preset value, and then the dynamic disturbance is applied at the true triaxial stress preset value, and the stress-strain curve of the rock sample 17 is obtained, until the rock sample 17 is destroyed.

[0037] When the rock crack propagation characteristics under the coupling of hydraulic fracturing and dynamic disturbance need to be tested, first, the hydraulic fracturing pump is started, high-pressure water is injected into the hydraulic fracturing hole 25 of the rock sample 17 through the hydraulic fracturing pipe 26, and the internal micro cracks of the rock sample 17 are generated through the pressure action of the high-pressure water, so as to simulate the hydraulic fracturing state. When the hydraulic fracturing state simulation is completed, the rock sample 17 in the rock sample holder 2 is subjected to true triaxial stress by the six actuators of the true triaxial testing machine 8, the true triaxial stress is gradually increased until the preset value, and then the dynamic disturbance is applied at the true triaxial stress preset value, while the stress-strain curve of the rock sample 17 is obtained, until the rock sample 17 is destroyed.

[0038] The scheme in the embodiment is not used to limit the protection scope of the present application, and any equivalent implementation or change without departing from the present application is included in the protection scope of the present application.

Claims

1. A push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions, characterized in that: Including box, rock sample holder, holder outer transfer sliding table and holder outer transfer sliding rail; The box includes a rectangular frame, a static sealing plate and a dynamic sealing plate; A static sealing plate is fixed on the upper end, lower end, left end, right end and front end of the rectangular frame, and the rectangular frame with the static sealing plate is fixedly installed in the lifting pressure chamber of the true triaxial test machine; The holder outer transfer sliding rail is horizontally fixed outside the lifting pressure chamber, and the holder outer transfer sliding table is arranged on the holder outer transfer sliding rail; The holder inner transfer outer guide rail is horizontally fixed on the upper surface of the holder outer transfer sliding table; The holder inner transfer inner guide rail is horizontally fixed in the rectangular frame, and the holder inner transfer inner guide rail is parallel to the holder outer transfer sliding rail; The holder inner transfer inner guide rail is located on the extension line of the holder inner transfer outer guide rail; The holder inner transfer sliding table is arranged above the holder inner transfer outer guide rail and the holder inner transfer inner guide rail, the rock sample holder is placed on the upper surface of the holder inner transfer sliding table, and a loading hole is formed in the center of the holder inner transfer sliding table; The dynamic sealing plate is vertically fixed on the upper surface of the holder inner transfer sliding table, and the dynamic sealing plate and the rear end of the rectangular frame are spliced to form a closed box.

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 loading hole is formed in the center of each static sealing plate, and an inner force transmission column is arranged in each center loading hole of the static sealing plate; Each inner force transmission column is connected with the actuator piston rod on the same side of the true triaxial test machine in a magnetic attraction mode; A loading hole is also formed in the center of the dynamic sealing plate, and an outer force transmission column is arranged in the center loading hole of the dynamic sealing plate.

3. The push-pull hard rock true triaxial specimen box with high temperature and hydraulic fracturing functions according to claim 1, characterized in that: The rock sample holder includes a rock sample clamping assembly and a rock sample heat preservation frame; The number of the rock sample clamping assembly is six, and one set of the rock sample clamping assembly is arranged at the upper end, lower end, left end, right end, front end and rear end of the rock sample; The rock sample heat preservation frame is sleeved outside the rock sample and located between the six sets of rock sample clamping assemblies.

4. The push-pull hard rock true triaxial specimen chamber with high temperature and hydraulic fracturing functions according to claim 3, characterized in that: Rock sample deformation measurement sensors are arranged 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.

5. The push-pull hard rock true triaxial specimen chamber with high temperature and hydraulic fracturing functions according to claim 3, characterized in that: The rock sample clamping assembly includes a force transmission pad, a cooling pad and a heating pad; The heating pad is in abutting contact with the rock sample; The cooling pad is fixedly clamped between the force transmission pad and the heating pad.

6. The push-pull hard rock true triaxial specimen chamber with high temperature and hydraulic fracturing functions according to claim 5, characterized in that: A heating resistance wire and a temperature sensor are embedded in the heating pad, and the heating resistance wire and the temperature sensor are respectively electrically connected with the main control system of the true triaxial test machine through wires.

7. The push-pull hard rock true triaxial specimen chamber with high temperature and hydraulic fracturing functions according to claim 5, characterized in that: A cooling water channel is embedded in the cooling pad, and the cooling water channel is communicated with a cooling water tank outside the true triaxial test machine through a circulating water pipe, and a circulating water pump is arranged between the circulating water pipe and the cooling water tank.

8. The push-pull hard rock true triaxial specimen chamber with high temperature and hydraulic fracturing functions according to claim 5, characterized in that: A hydraulic fracturing hole is arranged on the rock sample, a hydraulic fracturing pipe is inserted into the hydraulic fracturing hole, the hydraulic fracturing pipe penetrates 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 with a hydraulic fracturing pump outside the true triaxial test machine, and the hydraulic fracturing pump is connected with a water source.

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