A rock double-sided shear test device and test method

Abstract

The present invention provides a rock double-sided shear test device and test method, which relate to the field of rock testing. The test device includes a main frame, a base, a shearing fixture, a tangential loading mechanism, a first normal loading mechanism, a second normal loading mechanism and a control system. The base is arranged on the inner side of the main frame, and the shearing fixture is installed on the base; the tangential loading mechanism is arranged opposite to the shearing fixture, and the tangential loading mechanism is provided with a tangential pressure head, which cooperates with the tangential positioning part of the shearing fixture to apply a relative tangential load to the rock sample; the first normal loading mechanism and the second normal loading mechanism are located on the opposite side of the shearing fixture; the two normal loading mechanisms are both provided with normal pressure heads, and the two normal pressure heads are used to apply relative normal loads to the rock sample; the control system is electrically connected to the tangential loading mechanism, the first normal loading mechanism and the second normal loading mechanism respectively to control the two normal loading mechanisms to generate independent load forms.

Description

Technical Field

[0001] The invention relates to the technical field of rock testing, and in particular to a rock double-sided shear testing device and a testing method. Background Art

[0002] Underground faults may trigger earthquakes when disturbed, and studying the slip laws and mechanical properties of rock faults is of great significance to studying geological disasters such as earthquakes. Since the stress forms of faults are diverse, conventional single-sided shear tests cannot accurately reflect the stress state of rocks.

[0003] Subsequently, a Chinese utility model patent with authorization announcement number CN203758856U and authorization announcement date 2014.08.06 appeared, disclosing a rock structural surface bidirectional shear test device, which specifically includes a specimen, a pressure plate device, a roller group device, a loading device, a data acquisition device and a base; the specimen is an upper and lower rock block bounded by a rock structural surface; the pressure plate device is composed of four pressure plates, upper, lower, left and right, the lower pressure plate is placed on the base, and the left pressure plate and the right pressure plate are arranged in parallel and staggered; the loading device is divided into a normal pressure loading device and a bidirectional shear force loading device; the roller group device includes four pressure roller groups, which connect the loading device and the pressure plate device to reduce the friction between the specimen and the loading device; the data acquisition device collects pressure and displacement data.

[0004] The rock structure surface bidirectional shear test device in the prior art is provided with a bidirectional loading device, which can simultaneously apply shear force to the upper and lower plate rock blocks of the rock structure surface to obtain the shear strength and shear characteristics of the rock structure surface. When the normal pressure loading device applies normal pressure to the test piece, the hydraulic cylinder transmits the normal pressure to the upper plate rock block through the upper pressure head, and the lower plate rock block is placed on the base through the lower pressure plate, and the lower plate rock block is subjected to the normal reaction force generated by the base, and the normal pressure and the normal reaction force are completely synchronized.

[0005] Therefore, the existing test device can only generate synchronous normal force on the specimen. In fact, the normal load on the rock section may be different, and it is impossible to truly simulate the force form of the rock under complex normal loads. Summary of the invention

[0006] In order to solve the above problems, the purpose of the present invention is to provide a rock double-sided shear test device and test method to solve the problem that the normal loads on the rock section may be different and the existing test device cannot truly simulate the force form of the rock under complex normal loads.

[0007] The technical solution of the rock double-sided shear test device of the present invention is:

[0008] The rock double-sided shear test device comprises a main frame, a base, a shearing tool, a tangential loading mechanism, a first normal loading mechanism, a second normal loading mechanism and a control system, wherein the base is arranged on the inner side of the main frame, and the shearing tool is installed on the base;

[0009] The tangential loading mechanism is arranged opposite to the shearing fixture, the shearing fixture has a tangential positioning portion, and the tangential loading mechanism is provided with a tangential pressure head, the tangential pressure head cooperates with the tangential positioning portion to apply a relative tangential load to the rock sample;

[0010] The first normal loading mechanism and the second normal loading mechanism are respectively installed on the inner side of the main frame, and the first normal loading mechanism and the second normal loading mechanism are located on opposite sides of the shearing tool;

[0011] The first normal loading mechanism is provided with a first normal pressure head, and the second normal loading mechanism is provided with a second normal pressure head, and the first normal pressure head and the second normal pressure head are used to apply relative normal loads to the rock sample;

[0012] The control system is electrically connected to the tangential loading mechanism, the first normal loading mechanism, and the second normal loading mechanism respectively, so as to control the first normal loading mechanism and the second normal loading mechanism to generate independent load forms.

[0013] Furthermore, the tangential pressure head is provided with a tangential displacement detection element, and the tangential displacement detection element is used to detect the tangential displacement deformation of the rock sample;

[0014] The first normal pressure head is provided with a first normal displacement detection element, and the second normal pressure head is provided with a second normal displacement detection element. The first normal displacement detection element and the second normal displacement detection element are respectively used to detect the normal displacement deformation of the rock sample.

[0015] Furthermore, the tangential loading mechanism, the first normal loading mechanism, and the second normal loading mechanism are respectively equipped with built-in pressure sensors, and the pressure sensors are electrically connected to the control system. The pressure sensors are used to detect the pressure applied by the pressure head to the sample and feed back the pressure signal to the control system.

[0016] Further, the tangential loading mechanism is a tangential loading hydraulic cylinder, and the tangential pressure head is installed at the free end of the normal loading hydraulic cylinder;

[0017] The first normal loading mechanism is a first normal loading hydraulic cylinder, and the first normal pressure head is installed at the free end of the first normal loading hydraulic cylinder;

[0018] The second normal loading mechanism is a second normal loading hydraulic cylinder, and the second normal pressure head is installed at the free end of the second normal loading hydraulic cylinder.

[0019] Furthermore, the shearing tool is provided with a first guide structure and a second guide structure on the side corresponding to the tangential loading mechanism, the first normal pressure head is translationally assembled on the upper side of the first guide structure, and the second normal pressure head is translationally assembled on the upper side of the second guide structure.

[0020] Furthermore, a receiving groove is provided in the middle of the shearing tool, the tangential positioning portion is located on both sides of the notch of the receiving groove, and the first guide structure and the second guide structure are respectively arranged on the outer sides of the tangential positioning portion.

[0021] Furthermore, a groove is provided on the upper side of the base, and the shearing tool is matched with the groove of the base, and upper flanges are provided on both sides of the shearing tool, and the upper flanges extend outward to the upper surface of the groove of the base, and the first guide structure and the second guide structure are respectively arranged on the upper flanges.

[0022] Furthermore, a pad and a slide rail are provided on the inner side of the main frame, the slide rail is fixedly connected to the pad, the length direction of the slide rail is extended parallel to the normal direction, and the base is slidably installed on the slide rail.

[0023] Further, the main frame has a rectangular outline shape, and includes a lower side beam, an upper side beam, a first side column and a second side column that are fixedly connected, the base is installed on the lower side beam of the main frame, the tangential loading mechanism is installed on the upper side beam of the main frame, the first normal loading mechanism is installed on the first side column of the main frame, and the second normal loading mechanism is installed on the second side column of the main frame;

[0024] Normal pressing members are respectively provided between the first side column and the base, and between the second side column and the base, and the normal pressing members are used to adjust and press the position of the base to fix it.

[0025] The technical solution of the rock double-sided shear test method of the present invention is:

[0026] The test method using the above-mentioned rock double-sided shear test device includes the following steps:

[0027] Step 1: Select three rock samples, clamp two rock samples on the outside of the middle rock sample, and adjust the height of the middle rock sample according to the direct shear distance;

[0028] Step 2: Install three rock samples on the shearing fixture, control the first normal loading mechanism and the second normal loading mechanism to clamp the three rock samples, and control the tangential loading mechanism to make the tangential pressure head pre-contact the middle rock sample;

[0029] Step 3: according to the test requirements, set the pressure and loading form applied by the tangential loading mechanism, the first normal loading mechanism, and the second normal loading mechanism;

[0030] Step 4: The control system controls the tangential loading mechanism, the first normal loading mechanism, and the second normal loading mechanism to perform a loading test, and the load forms generated by the first normal loading mechanism and the second normal loading mechanism are independent of each other;

[0031] Step 5: The control system receives the loading pressure fed back by the tangential loading mechanism, the first normal loading mechanism and the second normal loading mechanism, and records the displacement and deformation data of the three rocks.

[0032] Beneficial effects: The rock double-sided shear test device adopts a design form of a main frame, a base, a shearing fixture, a tangential loading mechanism, a first normal loading mechanism, a second normal loading mechanism and a control system. The tangential loading mechanism and the shearing fixture are arranged opposite to each other, and the tangential pressure head of the tangential loading mechanism cooperates with the tangential positioning part of the shearing fixture to generate a tangential loading effect on the rock sample; the first normal loading mechanism and the second normal loading mechanism are located on opposite sides of the shearing fixture, and relative normal loads are applied to the rock sample through the first normal pressure head and the second normal pressure head respectively.

[0033] Among them, the control system is electrically connected to the tangential loading mechanism, the first normal loading mechanism, and the second normal loading mechanism respectively, and can control the tangential loading mechanism to generate accurate tangential load on the rock sample, and the two normal loading mechanisms to generate accurate normal loads on the rock sample respectively; because there are two normal loading mechanisms relatively arranged, the load forms generated by the first normal loading mechanism and the second normal loading mechanism are independent of each other, and a variety of normal loading forms can be applied to the rock sample, such as one side fixed and the other side loaded, one side linearly loaded and the other side sinusoidally loaded, or custom waveform loading, which can truly simulate the force form of rock under complex normal loads. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic front view of a rock double-sided shear test device in a specific embodiment of the rock double-sided shear test device of the present invention;

[0035] Figure 2 It is a three-dimensional schematic diagram of a rock double-sided shear test device in a specific embodiment of the rock double-sided shear test device of the present invention;

[0036] Figure 3It is a side view schematic diagram of a rock double-sided shear test device (when the first side column is omitted) in a specific embodiment of the rock double-sided shear test device of the present invention;

[0037] Figure 4 It is a front view of the assembly of the shearing tool and two normal pressure heads in a specific embodiment of the rock double-sided shear test device of the present invention.

[0038] In the figure: 1-main frame, 11-backing plate, 12-slide rail, 13-normal tightening member, 14-base baffle;

[0039] 2-base, 21-fixed bracket, 3-cutting tool, 30-accommodating groove, 31-upper flange, 32-first guide structure, 4-tangential loading mechanism, 40-tangential pressure head, 41-tangential displacement detection element;

[0040] 5 - first normal loading mechanism, 50 - first normal pressure head, 51 - first normal displacement detection element;

[0041] 6 - second normal loading mechanism, 60 - second normal pressure head, 61 - second normal displacement detection element. DETAILED DESCRIPTION

[0042] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0043] A specific embodiment 1 of the rock double-sided shear test device of the present invention is as follows: Figures 1 to 4 As shown, the rock double-sided shear test device includes a main frame 1, a base 2, a shearing fixture 3, a tangential loading mechanism 4, a first normal loading mechanism 5, a second normal loading mechanism 6 and a control system. The base 2 is arranged on the inner side of the main frame 1, and the shearing fixture 3 is installed on the base 2; the tangential loading mechanism 4 is arranged opposite to the shearing fixture 3, and the shearing fixture 3 has a tangential positioning portion. The tangential loading mechanism 4 is provided with a tangential pressure head 40, and the tangential pressure head 40 cooperates with the tangential positioning portion of the shearing fixture 3 to apply a relative tangential load to the rock sample.

[0044] The first normal loading mechanism 5 and the second normal loading mechanism 6 are respectively installed on the inner side of the main frame 1, and the first normal loading mechanism 5 and the second normal loading mechanism 6 are located on the opposite side of the shearing tool 3; the first normal loading mechanism 5 is provided with a first normal pressure head 50, and the second normal loading mechanism 6 is provided with a second normal pressure head 60, and the first normal pressure head 50 and the second normal pressure head 60 are used to apply relative normal loads to the rock sample; the control system is electrically connected to the tangential loading mechanism 4, the first normal loading mechanism 5, and the second normal loading mechanism 6, respectively, to control the first normal loading mechanism 5 and the second normal loading mechanism 6 to generate independent load forms.

[0045] The rock double-sided shear test device adopts a design form of a main frame 1, a base 2, a shearing fixture 3, a tangential loading mechanism 4, a first normal loading mechanism 5, a second normal loading mechanism 6 and a control system. The tangential loading mechanism 4 is arranged opposite to the shearing fixture 3, and the tangential pressure head 40 of the tangential loading mechanism 4 cooperates with the tangential positioning part of the shearing fixture 3 to generate a tangential loading effect on the rock sample; the first normal loading mechanism 5 and the second normal loading mechanism 6 are located on opposite sides of the shearing fixture 3, and relative normal loads are applied to the rock sample through the first normal pressure head 50 and the second normal pressure head 60 respectively.

[0046] Among them, the control system is electrically connected to the tangential loading mechanism 4, the first normal loading mechanism 5, and the second normal loading mechanism 6 respectively, and can control the tangential loading mechanism 4 to generate accurate tangential load on the rock sample, and the two normal loading mechanisms to generate accurate normal loads on the rock sample respectively; precisely because there are two normal loading mechanisms relatively arranged, the load forms generated by the first normal loading mechanism 5 and the second normal loading mechanism 6 are independent of each other, and a variety of normal loading forms can be applied to the rock sample, such as one side fixed and the other side loaded, one side linearly loaded and the other side sinusoidally loaded, or custom waveform loading, which can truly simulate the force form of rock under complex normal loads.

[0047] In this embodiment, a tangential displacement detection element 41 is provided on the tangential pressure head 40, and the tangential displacement detection element 41 is used to detect the tangential displacement deformation of the rock sample; a first normal displacement detection element 51 is provided on the first normal pressure head 50, and a second normal displacement detection element 61 is provided on the second normal pressure head 60, and the first normal displacement detection element 51 and the second normal displacement detection element 61 are respectively used to detect the normal displacement deformation of the rock sample. Specifically, the tangential displacement detection element 41, the first normal displacement detection element 51, and the second normal displacement detection element 61 are all displacement sensors. In addition, a fixed bracket 21 is connected to the base 2, and the two normal displacement detection elements are both installed on the fixed bracket 21. Correspondingly, the first normal pressure head 50 and the second normal pressure head 60 are respectively provided with detection plates, and the normal displacement detection elements obtain the displacement changes of the normal pressure head and the rock sample by sensing the distance to the corresponding detection plate.

[0048] Among them, the tangential loading mechanism 4, the first normal loading mechanism 5, and the second normal loading mechanism 6 are respectively equipped with pressure sensors, which are electrically connected to the control system. The pressure sensors are used to detect the pressure applied by the pressure head to the sample and feed back the pressure signal to the control system. Specifically, the tangential loading mechanism 4 is a tangential loading hydraulic cylinder, and the tangential pressure head 40 is installed at the free end of the normal loading hydraulic cylinder; the first normal loading mechanism 5 is a first normal loading hydraulic cylinder, and the first normal pressure head 50 is installed at the free end of the first normal loading hydraulic cylinder; the second normal loading mechanism 6 is a second normal loading hydraulic cylinder, and the second normal pressure head 60 is installed at the free end of the second normal loading hydraulic cylinder.

[0049] The test device also includes an oil pump and an oil supply pipeline. The oil supply pipeline is connected between the oil pump and each loading hydraulic cylinder, and hydraulic oil is input to each loading hydraulic cylinder through the oil supply pipeline. Moreover, the control system includes a computer control system and a servo control system. During the test, the power is turned on to start the oil pump, the servo control system is turned on, and the test steps are edited on the supporting system software. During the test, the computer control system inputs commands to the servo control system, and then the servo control system controls the oil pump to provide oil pressure to each loading hydraulic cylinder. Each loading hydraulic cylinder feeds back the loaded shear force and normal force to the servo control system. The servo control system regulates or cools the system according to the oil source state fed back by the oil pump and the oil temperature fed back by the cooling system. Finally, the data is fed back to the computer control system.

[0050] In this embodiment, the shearing tool 3 is provided with a first guide structure 31 and a second guide structure 32 on the side corresponding to the tangential loading mechanism 4, the first normal pressure head 50 is assembled on the upper side of the first guide structure 31, and the second normal pressure head 60 is assembled on the upper side of the second guide structure 32. A receiving groove 30 is provided in the middle of the shearing tool 3, the tangential positioning part is located on both sides of the notch of the receiving groove 30, and the first guide structure 31 and the second guide structure 32 are respectively arranged on the outer side of the tangential positioning part of the shearing tool 3.

[0051] Preferably, the first guide structure 31 and the second guide structure 32 have the same structure. Taking the first guide structure 31 as an example, it includes a fixed plate and a plurality of rollers. The fixed plate is arranged on the shearing tool 3. A plurality of rolling grooves are opened on the fixed plate. The plurality of rollers are rotatably installed in the rolling grooves of the fixed plate. The upper side surfaces of the plurality of rollers form a rolling plane. The two normal pressure heads are respectively placed on the corresponding rolling planes, which can reduce the moving friction of the normal pressure head and improve the accuracy of the extrusion effect applied by the normal pressure head.

[0052] Among them, a groove is provided on the upper side of the base 2, and the shearing tool 3 is matched with the groove of the base 2 in a concave-convex manner, and upper flanges 33 are respectively provided on both sides of the shearing tool 3, and the upper flanges 33 extend outward to the upper surface of the notch of the base 2, and the first guide structure 31 and the second guide structure 32 are respectively arranged on the upper flanges 33 of the shearing tool 3. The upper flange 33 is used as the installation basis of the first guide structure 31 and the second guide structure 32, and the upper flange 33 is placed on the upper surface of the notch of the base 2, which can ensure that the two normal pressure heads play a stable vertical support role.

[0053] A pad 11 and a slide rail 12 are provided on the inner side of the main frame 1. The slide rail 12 is fixedly connected to the pad 11. The length direction of the slide rail 12 is extended parallel to the normal direction. The base 2 is slidably installed on the slide rail 12, and a base baffle 14 is provided on the pad 11. The front and rear positions of the base 2 are limited by the base baffle 14 to ensure that the left and right positions of the base 2 can be accurately adjusted along the slide rail 12.

[0054] The main frame 1 has a rectangular outline shape, which includes a lower side beam, an upper side beam, a first side column and a second side column that are fixedly connected. The base 2 is installed on the lower side beam of the main frame 1, the tangential loading mechanism 4 is installed on the upper side beam of the main frame 1, the first normal loading mechanism 5 is installed on the first side column of the main frame 1, and the second normal loading mechanism 6 is installed on the second side column of the main frame 1.

[0055] Normal pressing members 13 are respectively provided between the first side column and the base 2 and between the second side column and the base 2, and are used to adjust the position of the pressing and fixing base 2. By using two normal pressing members 13 to press against the left side and the right side of the base 2 respectively, the left and right positions of the base 2 can be adjusted according to the test requirements, and the base 2 can be reliably fixed at a certain position, thereby ensuring that accurate shear load is applied to the rock sample.

[0056] The test method using the above-mentioned rock double-sided shear test device includes the following steps:

[0057] Step 1: Select three rock samples, clamp two rock samples on the outside of the middle rock sample, and adjust the height of the middle rock sample according to the direct shear distance. Depending on the actual situation to be simulated, smooth rock samples or rough rock samples can be used, and interlayers of different materials can be set between the contact surfaces of the rock samples.

[0058] Step 2: Install three rock samples on the shearing fixture 3, control the first normal loading mechanism 5 and the second normal loading mechanism 6 to clamp the three rock samples, and control the tangential loading mechanism 4 to pre-contact the tangential pressure head 40 with the middle rock sample. Before starting the test, the clamping force of the first normal loading mechanism 5 and the second normal loading mechanism 6 on the rock sample is the set horizontal normal stress, and then control the tangential loading mechanism 4 to slowly lower the tangential pressure head 40, so that the tangential pressure head 40 directly forms pre-contact with the middle rock sample.

[0059] Step 3: According to the test requirements, set the pressure and loading form applied by the tangential loading mechanism 4, the first normal loading mechanism 5, and the second normal loading mechanism 6. One of the normal loading mechanisms can be set to be stationary, and the other normal loading mechanism can apply the load; or one of the normal loading mechanisms can be set to apply a linear wave load, and the other normal loading mechanism can be set to apply a sine wave load; or, the loading waveforms of the two normal loading mechanisms can be customized, such as seismic waves.

[0060] Step 4: The control system controls the tangential loading mechanism 4, the first normal loading mechanism 5, and the second normal loading mechanism 6 to perform loading tests. The load forms generated by the first normal loading mechanism 5 and the second normal loading mechanism 6 are independent of each other. Specifically, the computer control system inputs commands to the servo control system, and then the servo control system controls the oil pump to provide oil pressure to each loading mechanism. Each loading mechanism feeds back the shear force and normal force of the loading to the servo control system, and the servo control system feeds back the data to the computer control system.

[0061] Step 5. The control system receives the loading pressure fed back by the tangential loading mechanism, the first normal loading mechanism and the second normal loading mechanism, and records the displacement and deformation data of the three rocks. The pressure is detected by the built-in pressure sensor of each loading mechanism, and the displacement and deformation data of the sample are detected in combination with the displacement detection element. During the test, the sample device can automatically record the test data, draw images and generate tables.

[0062] The specific embodiments of the rock double-sided shear test method of the present invention are the same as the specific embodiments of the test method using the above-mentioned rock double-sided shear test device in the specific implementation mode of the rock double-sided shear test device of the present invention, and will not be repeated here.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A rock double-sided shear test device, characterized in that: It includes a main frame, a base, a shearing tool, a tangential loading mechanism, a first normal loading mechanism, a second normal loading mechanism and a control system, wherein the base is arranged on the inner side of the main frame, and the shearing tool is installed on the base; The tangential loading mechanism is arranged opposite to the shearing fixture, the shearing fixture has a tangential positioning portion, and the tangential loading mechanism is provided with a tangential pressure head, the tangential pressure head cooperates with the tangential positioning portion to apply a relative tangential load to the rock sample; The first normal loading mechanism and the second normal loading mechanism are respectively installed on the inner side of the main frame, and the first normal loading mechanism and the second normal loading mechanism are located on opposite sides of the shearing tool; The first normal loading mechanism is provided with a first normal pressure head, and the second normal loading mechanism is provided with a second normal pressure head, and the first normal pressure head and the second normal pressure head are used to apply relative normal loads to the rock sample; The control system is electrically connected to the tangential loading mechanism, the first normal loading mechanism, and the second normal loading mechanism respectively, so as to control the first normal loading mechanism and the second normal loading mechanism to generate independent load forms; The tangential pressure head is provided with a tangential displacement detection element, and the tangential displacement detection element is used to detect the tangential displacement deformation of the rock sample; The first normal pressure head is provided with a first normal displacement detection element, and the second normal pressure head is provided with a second normal displacement detection element, and the first normal displacement detection element and the second normal displacement detection element are respectively used to detect the normal displacement deformation of the rock sample; The tangential loading mechanism is a tangential loading hydraulic cylinder, and the tangential pressure head is installed at the free end of the tangential loading hydraulic cylinder; The first normal loading mechanism is a first normal loading hydraulic cylinder, and the first normal pressure head is installed at the free end of the first normal loading hydraulic cylinder; The second normal loading mechanism is a second normal loading hydraulic cylinder, and the second normal pressure head is installed at the free end of the second normal loading hydraulic cylinder; The shearing tool is provided with a first guide structure and a second guide structure on the side corresponding to the tangential loading mechanism, the first normal pressure head is assembled translationally on the upper side of the first guide structure, and the second normal pressure head is assembled translationally on the upper side of the second guide structure; A receiving groove is provided in the middle of the shearing tool, the tangential positioning portion is located at both sides of the notch of the receiving groove, and the first guide structure and the second guide structure are respectively arranged on the outer sides of the tangential positioning portion; A groove is provided on the upper side of the base, and the shearing tool is matched with the groove of the base, and upper flanges are provided on both sides of the shearing tool, and the upper flanges extend outward to the upper surface of the notch of the base, and the first guide structure and the second guide structure are respectively arranged on the upper flanges.

2. The rock double-sided shear test device according to claim 1 is characterized in that: The tangential loading mechanism, the first normal loading mechanism, and the second normal loading mechanism are respectively equipped with pressure sensors, which are electrically connected to the control system. The pressure sensors are used to detect the pressure applied by the pressure head to the sample and feed back the pressure signal to the control system.

3. The rock double-sided shear test device according to claim 1 is characterized in that: A pad and a slide rail are provided on the inner side of the main frame. The slide rail is fixedly connected to the pad. The length direction of the slide rail is extended parallel to the normal direction. The base is slidably installed on the slide rail.

4. The rock double-sided shear test device according to claim 3 is characterized in that: The main frame has a rectangular outline shape, and includes a lower side beam, an upper side beam, a first side column and a second side column that are fixedly connected, the base is installed on the lower side beam of the main frame, the tangential loading mechanism is installed on the upper side beam of the main frame, the first normal loading mechanism is installed on the first side column of the main frame, and the second normal loading mechanism is installed on the second side column of the main frame; Normal pressing members are respectively provided between the first side column and the base, and between the second side column and the base, and the normal pressing members are used to adjust and press the position of the base to fix it.

5. A test method using the rock double-sided shear test device as claimed in claim 1, characterized in that: The following steps are involved: Step 1: Select three rock samples, clamp two rock samples on the outside of the middle rock sample, and adjust the height of the middle rock sample according to the direct shear distance; Step 2: Install three rock samples on the shearing fixture, control the first normal loading mechanism and the second normal loading mechanism to clamp the three rock samples, and control the tangential loading mechanism to make the tangential pressure head pre-contact the middle rock sample; Step 3: according to the test requirements, set the pressure and loading form applied by the tangential loading mechanism, the first normal loading mechanism, and the second normal loading mechanism; Step 4: The control system controls the tangential loading mechanism, the first normal loading mechanism, and the second normal loading mechanism to perform a loading test, and the load forms generated by the first normal loading mechanism and the second normal loading mechanism are independent of each other; Step 5: The control system receives the loading pressure fed back by the tangential loading mechanism, the first normal loading mechanism and the second normal loading mechanism, and records the displacement and deformation data of the three rocks.

Images