Angle-variable subzero-temperature direct shear apparatus for rock and test operation method

Abstract

The invention relates to an angle-variable subzero-temperature direct shear apparatus for rock and a test operation method, belonging to the technical field of equipment for rock mechanics testing. The angle-variable subzero-temperature direct shear apparatus comprises a host framework, a vertical loading mechanism, a vertical load support mechanism, a horizontal loading mechanism, a horizontal load support mechanism, a shearing box, a temperature control system, a measurement and control system and a computer system. The shearing box is arranged in an insulation can of the temperature-control system and realizes a subzero-temperature testing environment; the shearing box comprises a shearing box body, an arc slide rail, a rotating member, a wing-shaped fixture block, a semi-circular guide groove plate, a middle separator plate, a swivel positioning mechanism, and front and back end caps; and the shape of the shearing box is maintained unchanged while the internal structure of the shearing box changes from time to time through simple operation, so the purpose of shearing rock samples with different-angle cracks is achieved. The direct shear apparatus for rock and the test operation method can effectively overcome problems in subzero-temperature and angle-variable shearing; and the direct shear apparatus is simple in the principles of the overall structure, convenient to operate, high in visualization degree, changeable in functions and good in applicability.

Description

[0001] Technical field: [0002] The invention belongs to the technical field of rock mechanics test equipment, and relates to a variable-angle negative temperature rock direct shear instrument and a test operation method. [0003] Background technique: [0004] With the rise of underground engineering in the new century, humans began to extensively contact and transform rock or rock mass, such as tunnel or shaft excavation, coal (deep) mining, oil and gas mining, radioactive waste storage, dam foundation construction, development and utilization of geothermal resources Wait. The engineering rock mass involved is different from the complete rock, and its mechanical behavior depends not only on the strength of the rock itself, but also on the development of joints and fissures in the rock mass, and multiphase media such as water, gas, and ice may exist in the fissures, and there are temperature, Complex problems of multi-field coupling such as stress and seepage. Among them, t...

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Problems solved by technology

[0005] At present, researchers at home and abroad have done a lot of experimental research on rock specimens containing fractures or structural planes, and obtained some research results, but the tests generally have the following deficiencies: 1. The specimens are regular and flat through prefabrication methods. This is very different from the cracks obtained by sampling in actual engineering, and the direct shear test of samples cannot reflect the mechanical properties of cracks in actual engineering; 2. The existing rock direct shear tests are all carried out at room temperature. The direct shear test of negative temperature rock has not been reported yet, especially the research on the direct shear test of rock with ice fractures is still blank; 3. The existing rock direct shear devices require that the joint surface of the rock sample is parallel to the bottom of the specimen Or pour the test rock sample with high-strength quick-setting material into the upper and lower shear boxes, and use the horizontal push method to achieve direct shearing of the predetermined cracks, and cannot shear the rock samples with any angle cracks; 4. The samples obtained in actual engineering Rock specimens contain cracks at different angles. Existing equipment cannot directly shear the specimens, and complex cutting and trimming are required, which greatly damages the specimen itself; 5. Different inclination angles and quantity The uniaxial compression strength of fractured rocks, but the strength of fractures at different angles of the rock cannot be obtained, so it is impossible to evaluate the impact of the fracture on the overall strength of the rock specimen, and it is also impossible to find the corresponding relationship between the fracture strength and the overall strength of the rock mass

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