WO2020087715A1

WO2020087715A1 - Testing device and method for performing progressive failure simulation on mining-affected rock mass

Info

Publication number: WO2020087715A1
Application number: PCT/CN2018/123287
Authority: WO
Inventors: 尹延春; 谭云亮; 赵同彬; 黄彬; 邱月; 房凯
Original assignee: 山东科技大学
Priority date: 2018-10-31
Filing date: 2018-12-25
Publication date: 2020-05-07
Also published as: CN109297823B; CN109297823A

Abstract

A testing device and method for performing progressive failure simulation on a mining-affected rock mass, relating to the technical field of rock mass mechanical testing devices, and resolving the technical issue of simulating a progressive failure process of a rock mass under mining-induced stress. The testing device comprises a flexible loading device (1) and a lateral pressure conversion device (2). The flexible loading device (1) comprises passive bearing cylinders (11), an axial pressure bearing plate (12), an axial pressure sensor (14), and an axial displacement sensor (15). The axial pressure sensor (14) and the axial displacement sensor (15) are used to monitor load and deformation of each of the passive bearing cylinders (11). The lateral pressure conversion device (2) comprises a fixed frame (21), a fixed plate (22), a triangular block combination (23), a lateral pressure bearing plate (24), and a lateral pressure sensor (25). The lateral pressure conversion device (2) converts an axial load into lateral pressure so as to apply lateral pressure. Also disclosed is a method employing the device to perform progressive failure testing on a mining-affected rock mass. The invention achieves flexible loading and axial non-uniform loading on a rock surface, is easy to operate, and reduces testing costs.

Description

Test device and test method for simulating progressive failure of moving rock mass

[0001] The present invention relates to the technical field of rock mechanics testing devices, and in particular to a testing device for simulating progressive failure of rock masses under mining conditions and a method of testing using the device.

Background technique

[0002] In underground projects such as mines and tunnels, the excavation of the chamber will cause the transfer and change of the stress of the original rock, so the surrounding rock of the chamber will be deformed and destroyed under the action of mining stress, and will be generated in the rock body in turn Fracture zone, plastic zone and elastic zone, and the study of the evolution law of the degree and extent of fracture zone and plastic zone is of great significance to the stability control of surrounding rock.

[0003] At present, in the laboratory test of rock mechanics, the study of deformation and failure of surrounding rock generally adopts similar material simulation tests and rock mechanics test methods, in which the test period of similar material simulation tests is long, the workload is large, and the deformation and failure of similar materials There is a certain gap between the characteristics and the real rock. Although the rock mechanics testing method can directly test the mechanical properties of rocks, the existing rock mechanics testing machines can generally only load uniformly distributed specimens of standard sizes, and the monitoring data is the overall strength and deformation of the specimens, which cannot reproduce the engineering chamber. The evolution process of surrounding rock under the condition of mining stress and the progressive failure characteristics from the side wall to the deep part.

[0004] In Chinese patent 201410206492.X, a test method for the evolution process of the mining stress field in deep mining is disclosed. This method realizes the non-uniform dynamic loading of large-scale coal by arranging several servo loading cylinders. The study of dynamic stress field provides a new test method. However, the mining stress in this test method is actively applied, and the process of stress self-transfer caused by coal deformation and failure cannot be analyzed, and the test device is bulky and costly. Therefore, in order to reduce costs, fully utilize the functions of conventional rock mechanics testing machines, realize laboratory simulation of progressive failure of rock masses caused by mining, and further improve the existing test equipment and test methods.

Summary of the invention

technical problem

Solution to the problem

Technical solution [0005] In order to solve the technical problem of the progressive failure process of rock masses under simulated mining stress conditions, the present invention provides a test device and test method for simulating progressive failure of rock masses. Specific technical solutions are as follows.

[0006] An experimental device for simulating progressive failure of mining rock masses, including a flexible loading device and a lateral pressure conversion device; the flexible loading device includes a passive bearing cylinder, an axial pressure plate, an axial pressure sensor, and an axial displacement The sensor; an axial pressure sensor is provided on the upper end of the passive bearing cylinder, an axial displacement sensor is installed on the side of the passive bearing cylinder, and an axial pressure plate is provided on the lower end of the passive bearing cylinder; the side pressure conversion The device includes a fixing frame, a fixing plate, a triangular block combination, a lateral pressure plate, a lateral pressure sensor and an industrial camera; the fixing frame is arranged above the passive bearing cylinder, and the fixing frame and the upper part of the rock mechanics testing machine are under pressure The column is connected; the fixed plate is arranged under the rock body test piece, the lower surface of the fixed plate is connected to the loading cylinder of the rock mechanics testing machine; the triangular block assembly includes a fixed triangular block and a sliding triangular block, the The fixed triangle block is fixedly arranged on the fixing plate, and the sliding triangle block and the fixing frame are slid through a slot and a steel ball Connection.

[0007] Preferably, the triangular block assembly is provided between the fixing frame and the fixing plate, the rock sample is placed between the axial pressure plate and the fixing plate, on the left and right of the rock sample A triangle block combination is provided on the side and the rear side, respectively.

[0008] It is further preferred that the inclined surfaces of the sliding triangular block and the fixed triangular block are attached to each other, and the inclination angle of the inclined surface is smaller than the maximum static friction angle between the inclined surfaces; the lateral side of the sliding triangular block is provided with a lateral pressure sensor and Lateral pressure plate.

[0009] It is further preferred that the lateral pressure sensor and the lateral pressure plate are connected by rolling steel balls; the lateral pressure plate is made of a high-strength transparent material.

[0010] It is further preferred that a plurality of mounting slots for industrial cameras are provided on the lateral pressure-bearing plate, and the mounting cameras are provided in the mounting slots.

[0011] It is also preferred that a plurality of passive bearing oil cylinders are provided above the rock sample; the oil inlet valve controls the content of hydraulic oil in the passive bearing oil cylinder, and the oil inlet valve is closed after being filled with hydraulic oil.

[0012] A test method using a test device simulating progressive failure of mining rock masses includes the following steps:

[0013] A. Connect the upper end fixing frame of the lateral pressure conversion device to the upper bearing column of the rock mechanics testing machine, and connect the fixing plate to the loading cylinder of the rock mechanics testing machine;

[0014] B. Open the oil inlet valve of the passive bearing cylinder, adjust and control the hydraulic oil inside each passive bearing cylinder separately After the content, close the oil inlet valve;

[0015] C. Place a rock sample, adjust the positions of the fixed triangular block, the sliding triangular block, and the lateral pressure plate in order, and install the industrial camera;

[0016] D. Turn on the rock mechanics testing machine for loading, and record the axial stress, axial displacement, lateral stress and loading time synchronously during the test. The industrial camera records the image of the side of the rock specimen in real time until the test The pieces are completely destroyed.

Beneficial effects of invention

Beneficial effect

[0017] The beneficial effects of the present invention include:

[0018] (1) Using a flexible loading device, the axial non-uniform force loading of different regions of the test piece is realized, and a plurality of passive bearing oil cylinders are used to achieve the flexible loading of the rock sample, so the device can simulate The progressive failure process of rock mass under mining conditions provides a basis for studying the stability control of surrounding rock.

[0019] (2) The lateral pressure conversion device realizes the conversion of the axial load into the lateral pressure through the combination of triangular blocks, and since the lateral pressure is realized by the axial pressure conversion, the lateral pressure and the shaft are realized Simultaneous application of pressure, lateral pressure and axial pressure are applied in conjunction with the test equipment, which better simulates the real stress state of the rock mass and further improves the reliability of laboratory rock mechanics tests.

[0020] (3) The test device for simulating progressive failure of mining rock mass can realize the direct improvement of the existing rock mechanics testing machine, save the manufacturing cost of the testing machine, and enable the ordinary uniaxial testing machine to achieve axial and lateral Loading in two directions; and the mechanical transmission structure is stable, ensuring the smooth transmission of pressure, and thus ensuring the accuracy of the test.

[0021] (4) The lateral pressure plate is made of high-strength transparent material, and the destruction form of the rock specimen during the test is recorded by installing an industrial camera, so that the visual monitoring of the pressure surface side of the rock specimen is realized .

[0022] In addition, the device has the advantages of simple structure, easy installation and disassembly, low manufacturing cost, matching with the existing test equipment, saving test cost and the like.

Brief description of the drawings

BRIEF DESCRIPTION

[0023] FIG. 1 is a schematic structural view of a test device for simulating progressive failure of mining rock masses;

[0024] FIG. 2 is a schematic cross-sectional structural view of a test device for simulating progressive failure of mining rock masses; [0025] FIG. 3 is a schematic diagram of the evolution of the axial stress of the rock specimen during the loading process;

[0026] In the drawings: 1- flexible loading device; 11- passive bearing cylinder; 12- axial pressure plate;

14-axial pressure sensor; 15-axial displacement sensor; 2-lateral pressure conversion device; 21-fixed frame; 22-fixed plate; 23-triangle block combination; 231-fixed triangle block; 232-sliding triangle block Body; 24-lateral pressure plate; 25-lateral pressure sensor; 26-industrial camera; 3-rock mechanics testing machine; 31-loading cylinder; 32-upper pressure column; 4-rock specimen.

Invention Example

Embodiments of the invention

[0027] Referring to FIG. 1 to FIG. 3, the present invention provides a test device and test method for simulating progressive failure of mining rock masses. The specific implementation manner is as follows.

[0028] As shown in FIGS. 1 and 2, a test device for simulating progressive failure of mining rock masses specifically includes a flexible loading device 1 and a lateral pressure conversion device 2. The flexible loading device 1 is used to achieve axial non-uniform force loading in different areas of the test piece, and the flexible loading of the rock test piece 4 is realized by using multiple passive bearing oil cylinders; the lateral pressure conversion device 2 is combined by a triangular block to make The uniaxial testing machine realized the conversion of axial load and lateral pressure.

[0029] Wherein, the flexible loading device 2 specifically includes a passive bearing cylinder 11, an axial pressure plate 12, an axial pressure sensor 14, and an axial displacement sensor 15. A plurality of passive bearing oil cylinders 11 are provided above the rock mass test piece 4, and the passive bearing oil cylinders 11 control the expansion and contraction of the passive bearing oil cylinders 11 through the oil inlet valve 13. The upper end of the passive bearing cylinder 11 is provided with an axial pressure sensor 14, and an axial displacement sensor 15 is installed on the side of the passive bearing cylinder 11 for real-time monitoring of axial pressure load and axial displacement. The lower end of the passive bearing cylinder 11 is provided with an axial pressure plate 12, which corresponds to the number of passive bearing cylinders 11, and the axial load plate 12 applies an axial load to the rock mass test piece. A plurality of passive load-bearing oil cylinders 11 are provided above the rock mass test piece 4, an oil inlet valve 13 controls the content of hydraulic oil in the passive load-bearing oil cylinder 11, and the oil inlet valve 13 is closed after being filled with hydraulic oil. The oil inlet valve 13 and the axial pressure sensor 14 are used to monitor and control the magnitude and distribution of the axial load, and can simulate and reproduce the rock support pressure curve during actual mining.

[0030] The side pressure conversion device 2 specifically includes a fixing frame 21, a fixing plate 22, a triangular block assembly 23, a lateral pressure plate 24, a lateral pressure sensor 25, and an industrial camera 26. The fixing frame 21 is provided above the passive bearing oil cylinder 11. The fixing frame 21 is connected to the upper pressure-bearing column of the rock mechanics testing machine 3, and may be connected by a screw thread. The fixed plate 22 is provided below the rock body test piece 4, the lower surface of the fixed plate 22 and the loading cylinder 3 at the lower part of the rock mechanics testing machine 3 1 is connected, the fixing plate 22 is made of a rigid and non-deformable material, and the fixing plate 22 and the loading cylinder 31 are connected by threads. The triangular block assembly 23 includes a fixed triangular block 231 and a sliding triangular block 232, wherein the fixed triangular block 231 is fixedly disposed on the fixed plate 22, and the sliding triangular block 232 and the fixed frame 21 are slidingly connected through a slot and a steel ball . The triangular block assembly 23 is provided between the fixed frame 21 and the fixed plate 22, and the rock sample 4 is placed between the axial pressure plate 12 and the fixed plate 22, on the left and right sides of the rock sample 4 and The rear side is respectively provided with a triangular block assembly 23, and the front side of the rock mass test piece 4 faces the air without being compressed. The inclined planes of the sliding triangle block 232 and the fixed triangle block 231 are in contact with each other. The inclination angle of the inclined plane is smaller than the maximum static friction angle between the inclined planes to ensure smooth sliding. A lateral pressure sensor 25 and a lateral pressure plate 24 are provided inside the sliding triangle block 232 for real-time monitoring of the pressure. The lateral pressure sensor 25 and the lateral pressure plate 24 are connected by rolling steel balls, and the lateral pressure plate 24 is made of a high-strength transparent material. The lateral pressure plate 24 is provided with a plurality of mounting slots for industrial cameras 26. The mounting slots are provided with industrial cameras 26. The industrial cameras 26 are used to record the lateral deformation of the rock mass specimen in real time, thereby realizing the rock mass specimen Visual monitoring of bearing surface

[0031] The device can simulate the progressive failure process of rock mass under mining conditions, and further provide a basis for studying the stability control of surrounding rock. Lateral pressure is achieved through the conversion of axial pressure. The linkage of lateral pressure and axial pressure better simulates the true stress state of the rock mass and further improves the reliability of laboratory rock mechanics tests. In addition, the structure of the test device is simple, installation and disassembly are convenient, and the manufacturing cost is low, which can be matched with that of the test equipment, which saves the test cost.

[0032] A test method using a test device simulating progressive failure of mining rock masses includes the following steps:

[0033] A. The upper end fixing frame 21 of the lateral pressure conversion device 2 is connected to the upper bearing column 32 of the rock mechanics testing machine 3, and the fixing plate 22 is connected to the loading cylinder 31 of the rock mechanics testing machine 3.

[0034] B. Open the oil inlet valve 13 of the passive bearing cylinder 11, adjust and control the internal hydraulic oil content of each passive bearing cylinder 11 according to the test plan, and then close the oil inlet valve 13.

[0035] C. Place the rock sample 4, adjust the position of the fixed triangular block 231, the sliding triangular block 232, the lateral pressure plate 24, and install the industrial camera 26.

[0036] D. Turn on the rock mechanics testing machine 3 for loading. During the test, the axial stress, axial displacement, lateral stress and loading time are recorded synchronously. The industrial camera 26 records the image of the side of the rock specimen in real time until the test The pieces are completely destroyed. The stress changes during loading of rock mass specimens are shown in Figure 3. [0037] The parts not mentioned in the present invention can be realized by adopting or borrowing from existing technologies. In addition, terms such as "axial pressure plate, fixing frame, fixing plate, triangular block combination, lateral pressure plate and industrial camera" are mostly used in this article, but the possibility of using other terms is not excluded. These terms are only used to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

[0038] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples, the changes, modifications, additions or replacements made by those skilled in the art within the substantive scope of the present invention are also It should belong to the protection scope of the present invention.

Claims

[Claim 1] An experimental device for simulating progressive failure of mining rock masses, characterized in that it includes a flexible loading device and a lateral pressure conversion device;

The flexible loading device includes a passive bearing cylinder, an axial pressure plate, an axial pressure sensor, and an axial displacement sensor; an upper end of the passive bearing cylinder is provided with an axial pressure sensor, and a shaft is installed on the side of the passive bearing cylinder A displacement sensor, the lower end of the passive bearing cylinder is provided with an axial pressure plate;

The lateral pressure conversion device includes a fixed frame, a fixed plate, a triangular block combination, a lateral pressure plate, a lateral pressure sensor, and an industrial camera; the fixed frame is disposed above the passive bearing oil cylinder, and the fixed frame and rock mechanics test The upper bearing column of the machine is connected; the fixed plate is arranged below the rock mass test piece, and the lower surface of the fixed plate is connected to the loading cylinder of the rock mechanics testing machine; the triangular block combination includes a fixed triangular block and a sliding triangle For the block body, the fixed triangle block body is fixedly arranged on the fixing plate, and the sliding triangle block body and the fixing frame are slidingly connected by a clamping groove and a steel ball.

[Claim 2] The test device for simulating progressive failure of mining rock mass according to claim 1, characterized in that, the triangular block combination is arranged between a fixed frame and a fixed plate, and the rock mass is tested The piece is placed between the axial pressure-bearing plate and the fixed plate, and a triangular block combination is provided on the left and right sides and the rear side of the rock mass test piece, respectively.

[Claim 3] The test device for simulating progressive failure of mining rock mass according to claim 2, characterized in that the inclined surfaces of the sliding triangle block and the fixed triangle block are attached to each other, and the inclination angle of the inclined plane Less than the maximum static friction angle between the inclined surfaces; the inside of the sliding triangle block is provided with a lateral pressure sensor and a lateral pressure plate.

[Claim 4] A test device for simulating progressive failure of mining rock mass according to claim 3, characterized in that the lateral pressure sensor and the lateral pressure plate are connected by rolling steel balls; The lateral pressure plate is made of high-strength transparent material.

[Claim 5] The test device for simulating progressive failure of mining rock mass according to claim 4, characterized in that the lateral pressure plate is provided with a plurality of mounting slots for industrial cameras, the mounting An industrial camera is installed in the tank.

[Claim 6] The test device for simulating progressive failure of mining rock mass according to claim 1, wherein a plurality of passive bearing oil cylinders are provided above the rock mass test piece; the oil inlet valve Control the content of hydraulic oil in the passive load cylinder, fill the hydraulic oil and close the oil inlet valve.

[Claim 7] A test device for simulating progressive failure of mining rock mass according to any one of claims 1 to 6, characterized in that the test method using the gradual failure test device of simulated mining rock mass includes the following steps :

A. Connect the upper end fixing frame of the lateral pressure conversion device to the upper pressure column of the rock mechanics testing machine, and connect the fixing plate to the loading cylinder of the rock mechanics testing machine;

B. Open the oil inlet valve of the passive load cylinder, adjust and control the hydraulic oil content inside each passive load cylinder separately, and close the oil inlet valve;

C. Place the rock sample, adjust the position of the fixed triangle block, slide the triangle block, and the lateral pressure plate in order, and install the industrial camera;

D. Turn on the rock mechanics testing machine for loading. During the test, the axial stress, axial displacement, lateral stress and loading time are recorded simultaneously. The industrial camera takes real-time images of the side of the rock specimen until the specimen is completely destroyed. .