A rock shear strength testing device, testing system and testing method

Abstract

The present application relates to the technical field of rock shearing, and especially relates to a rock shearing strength test device, a test system and a test method, wherein the test device comprises a counterforce base, horizontal loading devices, horizontal bearing plates, a vertical loading box, a vertical fixing box and vertical loading devices; the counterforce base has a loading chamber, a pair of horizontal loading devices are symmetrically arranged on two opposite side walls of the loading chamber, and each horizontal loading device is connected with a horizontal bearing plate; the vertical loading box and a groove on the vertical fixing box jointly form a space for placing a rock sample, and a roller is arranged on the contact surface of the vertical loading box and the vertical fixing box; the vertical loading devices apply a load to the sample through the vertical loading box. In the test process, the deformation and rupture characteristics of the rock shearing surface can be directly observed, the present application is more intuitive than the existing rock shearing device, is closer to the actual engineering, and has the characteristics of convenient operation and low cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rock shearing, in particular to a rock shearing strength test device, a test system and a test method. BACKGROUND

[0002] The rock direct shear apparatus is a device for measuring the shear strength of rock. Its working principle is to place the rock sample between the upper and lower shear boxes, apply a certain pressure vertically, and then apply a horizontal thrust to the lower shear box. Since the upper shear box is fixed, the lower shear box moves horizontally under the action of the thrust, causing the rock sample to move vertically until it is sheared and broken, thereby obtaining the shear strength parameters of the rock. However, when using the existing rock direct shear apparatus to measure the shear strength of rock, although the upper and lower shear boxes can move relative to each other, the gap between them is very small, making it impossible to directly observe the deformation and failure characteristics of the shear surface of the rock during shearing. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art and provide a rock shear strength test device that can directly observe the deformation and failure characteristics of the rock shear surface, making it more intuitive than existing rock shear devices.

[0004] To achieve the above-mentioned purpose, the present application provides a rock shear strength test device, which comprises a counterforce base, a horizontal loading device, a horizontal pressure plate, a vertical loading box, a vertical fixed box and a vertical loading device. The counterforce base has a loading chamber with an open top. A pair of horizontal loading devices for simulating horizontal pressure at different depths underground are symmetrically arranged on the left and right opposite sides of the loading chamber. Each horizontal loading device is provided with a horizontal pressure plate at the front end. The vertical loading box and the vertical fixed box have a U-shaped structure in cross section. The vertical fixed box is fixed with its opening facing upwards on the bottom plate of the loading chamber. First through holes for the output end of the horizontal loading device to pass through are arranged on the first and second side walls of the vertical fixed box, and a first accommodating groove is further arranged on the inner side of the first side wall of the vertical fixed box. The vertical loading box is arranged above the vertical fixed box with its opening facing downwards. Second through holes for the output end of the horizontal loading device to pass through are arranged on the first and second side walls of the vertical loading box. The second side wall of the vertical loading box is movably inserted into the opening of the vertical fixed box, and the first side wall of the vertical fixed box is movably arranged in the opening of the vertical loading box. A second accommodating groove corresponding to the first accommodating groove is arranged on the inner side of the second side wall of the vertical loading box. The second accommodating groove and the first accommodating groove together form a sample test space for placing a rock sample. The vertical loading device is connected to the vertical loading box to apply a load to the rock sample.

[0005] Further, a plurality of rollers are arranged on the side wall in contact between the vertical loading box and the vertical fixed box to reduce the friction therebetween.

[0006] Further, a plurality of first mounting grooves are arranged on the inner side of the first side wall of the vertical loading box, and a plurality of second mounting grooves are arranged on the inner sides of the first side wall and the second side wall of the vertical fixed box, and rollers are arranged in the plurality of first mounting grooves and the plurality of second mounting grooves, respectively.

[0007] Further, the horizontal pressure bearing plate is arranged in the sample test space, and the outer side of the horizontal pressure bearing plate has a connecting portion; the front end of the loading rod of the horizontal loading device is provided with a connecting groove for cooperating with the connecting portion, the connecting portion is inserted into the connecting groove, and the connecting portion is connected with the horizontal loading device through a screw rod.

[0008] Further, the front and rear sides of the loading chamber are provided with openings; and the sample test space is an open space with front and rear openings.

[0009] Further, a plurality of positioning connecting rods perpendicular to the loading direction of the horizontal loading device are horizontally arranged on the inner bottom plate of the loading chamber; and a plurality of positioning mounting grooves are formed on the bottom surface of the vertical fixed box, and the plurality of positioning mounting grooves are correspondingly and cooperatively mounted with the plurality of positioning connecting rods.

[0010] Further, the horizontal loading device is fixedly connected with the side wall of the loading chamber.

[0011] The application further provides a rock shear strength test system, which comprises the rock shear strength test device, a loading control system, a DIC non-contact measurement system and a camera.

[0012] The application further provides a rock shear strength test method, which uses the rock shear strength test system to perform the test.

[0013] S1, first, the vertical fixed box and the counterforce base are inserted and connected through the positioning mounting grooves and the positioning connecting rods to ensure that the vertical fixed box does not move during the test; then the vertical loading box is inserted, and rollers are arranged on the contact surface between the vertical loading box and the vertical fixed box to reduce the friction therebetween;

[0014] S2, the horizontal loading device is passed through the through hole on the vertical loading box and the vertical fixing box, and the horizontal pressure plate is connected with the corresponding horizontal loading device through the screw rod; the rock sample is placed in the sample test space;

[0015] S3, the horizontal loading device is connected with the loading control system through the pressure-bearing oil pipe, and the horizontal loading device is used to apply horizontal load to the rock sample;

[0016] S4, the camera is connected to the DIC non-contact measurement system through the connecting line; and the camera is adjusted to be aligned with the rock sample;

[0017] S5, the vertical loading device is connected with the loading control system through the pressure-bearing oil pipe;

[0018] S6, the DIC non-contact measurement system and the vertical loading device are started at the same time to ensure that the test data are recorded synchronously by starting the DIC non-contact measurement system and the vertical loading device, the vertical loading device applies vertical load to the rock sample until the rock sample is sheared and destroyed, and the test is completed.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] (1), a rock vertical shear test device, comprising a counterforce base, a horizontal loading device, a horizontal pressure plate, a vertical loading box, a vertical fixing box, a roller and a vertical loading device, the horizontal loading device is connected with the counterforce base through bolts, the horizontal pressure plate is connected with the horizontal loading device through a screw rod; the roller is arranged on the contact surface between the vertical loading box and the vertical fixing box; the vertical loading device applies load to the sample through the vertical loading box. The first accommodating groove arranged on the vertical fixing box and the second accommodating groove arranged on the vertical loading box jointly form a sample test space, and the horizontal pressure plate is located in the sample test space. By adjusting the horizontal loading pressure, the horizontal pressure at different depths is simulated; the vertical loading device is used to apply load to the vertical loading box, and the vertical loading box applies load to the sample under the action of the vertical loading device until the sample is sheared and destroyed, and then the vertical shear strength of the rock is measured. The test device has a reasonable structure, and the deformation and fracture characteristics of the rock shear surface can be directly observed from the side of the sample test space.

[0021] (2), a rock vertical shearing test system of the present application, comprising a test device, a camera, a DIC non-contact measurement system and a loading control system; the camera is used for obtaining the deformation and fracture change image of the shearing surface of the rock sample in the test process; the DIC non-contact measurement system is used for real-time monitoring of the deformation and fracture characteristics and strain variation law of the shearing surface of the rock sample. The test system of the present application can directly observe the deformation and fracture characteristics of the rock shearing surface, is closer to the actual engineering, and has the characteristics of convenient operation and low cost.

[0022] (3), a rock shearing strength test method of the present application, the DIC non-contact measurement system can real-time monitor the deformation and fracture characteristics of the rock shearing surface and its strain variation law, the DIC non-contact measurement system and the vertical loading device synchronously record the test data, ensure the real-time unification of deformation, strain and stress in the test process, and make the test result more accurate. The test method of the present application can directly observe the deformation and fracture characteristics of the rock shearing surface, is more intuitive than the existing rock shearing device, and is a brand-new rock shearing strength test method.

[0023] The rock vertical shearing test system can directly observe the deformation and fracture characteristics of the rock shearing surface, and is more intuitive than the existing rock shearing device.

[0024] In addition to the purposes, features and advantages described above, the present application has other purposes, features and advantages. The present application will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings are used to provide further understanding of the embodiments of the present application, and constitute a part of the specification, and are used to explain the embodiments of the present application together with the following specific embodiments, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0026] Figure 1 is a cross-sectional structure schematic view of a rock vertical shearing test device in the present application;

[0027] Figure 2 is a front structure schematic view of a vertical loading box in the present application;

[0028] Figure 3 is a side structure schematic view of the vertical loading box in the present application;

[0029] Figure 4 is a structure schematic view of a vertical fixing box in the present application;

[0030] Figure 5 is a combined structure schematic view of a counterforce base, a horizontal loading device and a horizontal pressure bearing plate in the present application;

[0031] Figure 6 is Figure 5Fig. 1 is a schematic view of the I-I cross-sectional structure in the present application;

[0032] Figure 7 Fig. 1 is a schematic view of the I-I cross-sectional structure in the present application;

[0033] Figure 8 Fig. 1 is a schematic view of the I-I cross-sectional structure in the present application;

[0034] Figure 9 Fig. 1 is a schematic view of the I-I cross-sectional structure in the present application;

[0035] In the drawings: 1-counterforce base; 1a-loading chamber; 2-horizontal loading device; 2a-connection groove; 2b-inlet and outlet port; 3-horizontal pressure plate; 5-vertical loading box; 5a-second through hole; 5b-second accommodating groove; 6-vertical fixing box; 6a-first through hole; 6b-first accommodating groove; 6c-positioning installation groove; 7-roller; 8-bolt; 9-positioning connecting rod; 10-vertical loading device; 11-camera; 12-connection line; 13-DIC non-contact measurement system; 14-pressure oil pipe; 15-loading control system. DETAILED DESCRIPTION

[0036] The present application will be described in detail below with reference to the embodiments shown in the drawings, but it should be noted that these embodiments are not a limitation on the present application, and equivalent transformations or substitutions of functions, methods, or structures made by those of ordinary skill in the art based on these embodiments are within the scope of the present application.

[0037] Please refer to Figures 1 to 8 The present embodiment provides a rock shear strength test device, which comprises a counterforce base 1, a horizontal loading device 2, a horizontal pressure plate 3, a screw rod 4, a vertical loading box 5, a vertical fixing box 6, a roller 7, and a vertical loading device 10; the specific structure is as follows:

[0038] The reaction force base 1 has a top-open loading chamber 1a, a pair of horizontal loading devices 2 are symmetrically arranged on the left and right opposite side walls of the loading chamber 1a, the horizontal loading devices 2 are fixedly connected with the reaction force base 1 through bolts 8, and each of the two horizontal loading devices 2 is provided with a horizontal pressure bearing plate 3 at the front end. The vertical loading box 5 and the vertical fixing box 6 are both in U-shaped structure, the vertical fixing box 6 is fixedly arranged on the bottom plate of the loading chamber 1a with the opening upward, the first side wall and the second side wall of the vertical fixing box 6 are both provided with a first through hole 6a for the output end of the horizontal loading device 2 to movably penetrate, and the first side wall of the vertical fixing box 6 is further provided with a first accommodating groove 6b; the vertical loading box 5 is arranged above the vertical fixing box 6 with the opening downward, the first side wall and the second side wall of the vertical loading box 5 are both provided with a second through hole for the output end of the horizontal loading device 2 to movably penetrate, the second side wall of the vertical loading box 5 is movably arranged inside the opening of the vertical fixing box 6, and the first side wall of the vertical fixing box 6 is movably arranged inside the opening of the vertical loading box 5; the second side wall of the vertical loading box 5 is provided with a second accommodating groove 5b corresponding to the first accommodating groove 6b, and the second accommodating groove 5b and the first accommodating groove 6b jointly form a sample test space for placing a rock sample A, and a vertical loading device 10 is connected to the vertical loading box 5 for applying load to the rock sample A.

[0039] In a specific embodiment, a plurality of rollers 7 are arranged on the side walls in contact between the vertical loading box 5 and the vertical fixing box 6. Specifically, a plurality of first mounting grooves are arranged on the inner side of the first side wall of the vertical loading box 5, a plurality of second mounting grooves are arranged on the inner sides of the first side wall and the second side wall of the vertical fixing box 6, and the rollers 7 are arranged in the first mounting grooves and the second mounting grooves respectively. The arrangement of the rollers 7 not only reduces the friction between the vertical loading box 5 and the vertical fixing box 6, but also avoids the occurrence of biasing or stress deflection during the test, reduces the system error during the test, and improves the test accuracy.

[0040] In a specific embodiment, the horizontal pressure bearing plate 3 is arranged in the sample test space, and the outer side of the horizontal pressure bearing plate 3 has a connecting portion. The front end of the loading rod of the horizontal loading device 2 is provided with a connecting groove 2a for cooperating with the connecting portion, the connecting portion is inserted into the connecting groove 2a, and the connecting portion is connected with the horizontal loading device 2 through a screw rod 4. Specifically, the horizontal loading device 2 is connected with the horizontal pressure bearing plate 3 through the screw rod 4, so that when the rock sample A is sheared and damaged, the horizontal loading device 2 will not be damaged due to excessive deformation of the vertical loading box 5 and the vertical fixing box 6, and the structure is reasonable.

[0041] In a specific embodiment, the front and back sides of the loading chamber 1a are provided with openings; the sample test space is an open space with front and back openings. This structure not only facilitates the combined installation of the vertical fixing box 6 and the counterforce base 1, but also facilitates the camera to obtain the change process data of the rock sample during the test.

[0042] In a specific embodiment, a plurality of positioning connecting rods 9 are horizontally arranged on the inner bottom plate of the loading chamber 1a and are perpendicular to the loading direction of the horizontal loading device 2; a plurality of positioning installation grooves 6c are formed on the bottom surface of the vertical fixing box 6, and the plurality of positioning installation grooves 6c are installed in one-to-one correspondence with the plurality of positioning connecting rods 9. During the test, the positioning installation grooves 6c of the vertical fixing box 6 are inserted into the positioning connecting rods 9 on the counterforce base 1 to ensure that the vertical fixing box 6 does not move. The horizontal loading device 2 is fixedly connected to the side wall of the loading chamber 1a through the bolts 8; both the horizontal loading device 2 and the vertical loading device 10 adopt a hydraulic driving device.

[0043] Please refer to Figure 9 , the embodiment of the present application also provides a rock shear strength test system, which comprises the rock shear strength test device, the camera 11, the DIC non-contact measurement system 13 and the loading control system 15 described above; the horizontal loading device 2 and the vertical loading device 10 in the rock shear strength test device are connected with the loading control system 15 respectively. According to the need, the camera 11 can be provided as one or more, and the camera 11 is arranged on one side of the rock shear strength test device through a triangular support device and is aligned with the rock sample A, and is used to obtain the deformation and fracture change image of the shear surface of the rock sample A during the test. The DIC non-contact measurement system is connected with the camera through a connecting line and is used to monitor the shear surface deformation and fracture characteristics and the strain change law of the rock sample A in real time. The rock vertical shear test system can simulate the horizontal pressure (lateral pressure) at different depths in the range of 0~300m by adjusting the horizontal loading pressure; the vertical loading device applies a load to the vertical loading box, and the vertical loading box applies a load to the sample until the sample is sheared and broken, and the size of the rock vertical shear strength can be measured; the test system can directly observe the deformation and fracture characteristics of the rock shear surface.

[0044] The embodiment of the present application also provides a rock shear strength test method, which uses the rock shear strength test system described above to perform the test, and the test method comprises the following steps:

[0045] S1, first, the positioning installation grooves 6c of the vertical fixing box 6 are inserted into the positioning connecting rods 9 on the counterforce base 1 to ensure that the vertical fixing box 6 does not move during the test; then, the vertical loading box 5 is inserted, and the roller 7 is arranged on the contact surface between the vertical loading box 5 and the vertical fixing box 6.

[0046] S2, pass the horizontal loading device 2 through the first through hole on the side wall of the vertical loading box 5 and the first through hole on the side wall of the vertical fixing box 6, and connect the horizontal pressure plate 3 with the corresponding horizontal loading device 2 through the screw rod 4, the horizontal pressure plate is located in the sample test space formed by the first containing groove and the second containing groove; then put the cubic rock sample A with the side length of 100mm into the sample test space.

[0047] S3, connect the inlet and outlet of the horizontal loading device 2 with the loading control system 15 through the pressure oil pipe 14, and apply the horizontal load to the rock sample A through the horizontal loading device 2; according to the actual stratum depth, the size of the load can be selected, and the horizontal pressure at different depths in the range of 0~300m can be simulated.

[0048] S4, connect the camera 11 to the DIC non-contact measurement system 13 through the connecting line 12; adjust the camera 11 to align with the rock sample A.

[0049] S5, connect the inlet and outlet of the vertical loading device 10 with the loading control system 15 through the pressure oil pipe 14.

[0050] S6, start the DIC non-contact measurement system 13 and the vertical loading device 10 at the same time, so as to ensure that the test data is recorded synchronously by the DIC non-contact measurement system 13 and the vertical loading device 10, the vertical loading device 10 applies the vertical load to the rock sample A until the rock sample A is sheared and damaged, and the test is completed. The DIC non-contact measurement system 13 can monitor the deformation and fracture characteristics of the rock shear surface and the strain change law in real time; the DIC non-contact measurement system 13 and the vertical loading device 10 record the test data synchronously, which ensures that the deformation, strain and stress are unified in real time during the test, so that the test result is more accurate.

[0051] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A rock shear strength testing apparatus, characterized by, The utility model relates to a rock sample test device, including counterforce base (1), horizontal loading device (2), horizontal pressure plate (3), vertical loading box (5), vertical fixed box (6) and vertical loading device (10), the counterforce base (1) has the loading chamber (1a) of top opening, a pair of horizontal loading device (2) for simulating the horizontal pressure of different depth at underground is symmetrically arranged on the left and right opposite side wall of loading chamber (1a), and the front end of each horizontal loading device (2) is equipped with horizontal pressure plate (3), the vertical loading box (5) and the vertical fixed box (6) are all U type structure, the opening of vertical fixed box (6) is fixedly arranged on the bottom plate of loading chamber (1a) upwards, the first side wall and the second side wall of vertical fixed box (6) are all equipped with the first through -hole (6a) of the output end movable penetration for horizontal loading device (2), and the inboard of first side wall of vertical fixed box (6) is also equipped with the first accommodation slot (6b), the vertical loading box (5) is set up above vertical fixed box (6) downwards, the first side wall and the second side wall of vertical loading box (5) are all equipped with the second through -hole (5a) of the output end movable penetration for horizontal loading device (2), the second side wall of vertical loading box (5) is movably inserted in the opening of vertical fixed box (6), and the first side wall of vertical fixed box (6) is movably arranged in the opening of vertical loading box (5), the inboard of second side wall of vertical loading box (5) is equipped with the second accommodation slot (5b) corresponding to the first accommodation slot (6b), the second accommodation slot (5b) and the first accommodation slot (6b) form the sample test space for placing rock sample (A) together, vertical loading device (10) is connected to vertical loading box (5) and is used to drive vertical loading box (5) to apply load to rock sample (A), horizontal pressure plate (3) is arranged in the sample test space, and the outside of horizontal pressure plate (3) has a connecting portion, the front end of the loading rod of horizontal loading device (2) is provided with a connecting groove (2a) for cooperating with the connecting portion, the connecting portion is inserted into the connecting groove (2a), and is connected with horizontal loading device (2) through screw rod (4).

2. The rock shear strength testing apparatus of claim 1, wherein, The side wall between the vertical loading box (5) and the vertical fixed box (6) is provided with a plurality of rollers (7) for reducing the friction therebetween.

3. The rock shear strength testing apparatus of claim 2, wherein, The inboard of the first side wall of the vertical loading box (5) is provided with a plurality of first mounting grooves, the inboard of the first side wall and the second side wall of the vertical fixed box (6) is provided with a plurality of second mounting grooves, and a roller (7) is arranged in each of the plurality of first mounting grooves and the plurality of second mounting grooves.

4. The rock shear strength testing apparatus of claim 1, wherein, A plurality of positioning connecting rods (9) are horizontally arranged on the bottom plate in the loading chamber (1a) and are perpendicular to the loading direction of the horizontal loading device (2); a plurality of positioning installation grooves (6c) are formed on the bottom surface of the vertical fixing box (6), and the plurality of positioning installation grooves (6c) are correspondingly matched and installed with the plurality of positioning connecting rods (9).

5. The rock shear strength testing apparatus of claim 1, wherein, The horizontal loading device (2) is fixedly connected with the side wall of the loading chamber (1a).

6. A rock shear strength testing system characterized by, The rock shear strength test device, the DIC non-contact measurement system (13), the camera (11) and the loading control system (15); the horizontal loading device (2) and the vertical loading device (10) in the rock shear strength test device are connected with the loading control system (15) through connecting lines (12), the camera (11) is arranged on one side of the rock shear strength test device and is used for acquiring the deformation and fracture change image of the shear surface of the rock sample (A) in the test process; the DIC non-contact measurement system (13) is connected with the camera (11) through a connecting line (12) and is used for monitoring the shear surface deformation and fracture characteristics and the strain change rule of the rock sample (A) in real time.

7. A method of testing the shear strength of rock, characterised in that, The rock shear strength test system is used to perform a test, and the test method comprises the following steps: S1, first, the vertical fixing box (6) is inserted and connected with the counterforce base (1) through the positioning installation groove (6c) and the positioning connecting rod (9), so that the vertical fixing box (6) does not move during the test; then, the vertical loading box (5) is inserted, and the roller (7) is arranged on the contact surface between the vertical loading box (5) and the vertical fixing box (6), so as to reduce the friction between the vertical loading box and the vertical fixing box; S2, the horizontal loading device (2) passes through the through hole on the vertical loading box (5) and the vertical fixing box (6), and the horizontal pressure bearing plate (3) is connected with the corresponding horizontal loading device (2) through the screw rod (4); the rock sample (A) is placed in the sample test space; S3, the horizontal loading device (2) is connected with the loading control system (15) through the pressure bearing oil pipe (14), and the horizontal load is applied to the rock sample (A) through the horizontal loading device (2); S4, the camera (11) is connected to the DIC non-contact measurement system (13) through the connecting line (12); and the camera (11) is adjusted to be aligned with the rock sample (A); S5, the vertical loading device (10) is connected with the loading control system (15) through the pressure bearing oil pipe (14); S6, the DIC non-contact measurement system (13) and the vertical loading device (10) are started at the same time, so as to ensure that the test data is recorded synchronously when the DIC non-contact measurement system (13) and the vertical loading device (10) are started; the vertical loading device (10) applies the vertical load to the rock sample (A), and the test is ended until the rock sample (A) is sheared and damaged.

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