Low-normal-friction split mounting type shear box for circular shearing of rock mass structural surface

Abstract

The invention belongs to the technical field of geotechnical engineering, and discloses a low-normal-friction split mounting type shear box for circular shearing of a rock mass structural surface. When cyclic tension-compression shear load is applied, the step stud connected with the shear loading end transmits the tension-compression load of the lower half part, and the fixed end pull shaft connected with the shear apparatus fixed end transmits the tension-compression load of the upper half part. When the sample generates normal displacement due to shear expansion or shear shrinkage, the sample drives the sliding block to freely move up and down along the groove guide rail, and the ball between the sliding block and the guide rail reduces friction and experimental errors of the sample in the normal direction. The low-normal-friction split mounting type shear box can meet cyclic compression and tensile stress application in a shear experiment, reduces normal friction, improves experiment precision, is simple in equipment structure, easy to disassemble and convenient to install, and has good adaptability, and for a sample with a certain size error, the close attachment of the shear box and the sample can be ensured by adjusting the position of the fastening block.

Description

technical field [0001] The invention relates to an assembled shear box, in particular to a low normal friction assembled shear box used for cyclic shearing of rock mass structural surfaces, and belongs to the technical field of geotechnical engineering. Background technique [0002] There are generally weak structural planes such as joints, cracks, and weak layers in the rock mass of underground engineering. These structural planes control the strength and stability of the rock mass and are crucial to engineering safety. Under the conditions of earthquake load, periodic storage and drainage of reservoirs, or coal seam mining, the rock mass is affected by cyclic shear loads along the structural plane, which further weakens the mechanical strength of the rock mass. Therefore, it is of great significance for the guidance of engineering safety analysis to conduct cyclic shearing on the rock mass structural plane at the laboratory scale to explore its failure mechanism and failur...

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Problems solved by technology

[0003] The purpose of the present invention is to solve the technical problems that it is difficult to apply cyclic tensile and compressive loads and the displacement in the normal direction of the sample is difficult to deform freely during the indoor shear experiment, and provides a low-pressure cyclic shearing method for rock mass structural planes. Assembled shear box with normal friction resistance to meet the requirements of shear chamber mechanical test

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