A Low Normal Friction Assembled Shear Box for Cyclic Shearing of Rock Mass Structural Surfaces

Abstract

The invention belongs to the technical field of geotechnical engineering, and discloses a low normal friction assembled shear box used for cyclic shearing of a rock mass structure surface. When a cyclic tensile and compressive shear load is applied, the stepped stud connected to the shear loading end transmits the tensile and compressive load of the lower half, and the fixed end pulling shaft connected to the fixed end of the shearing instrument transmits the tensile and compressive load of the upper half. When the normal displacement of the sample occurs due to shear expansion or shrinkage, the sample drives the slider to move up and down freely along the groove guide rail, and the balls between the slider and the guide rail reduce the friction and friction of the sample in the normal direction. Experimental error. The low normal friction assembled shear box of the present invention can satisfy the application of cyclic compression and tensile stress in the shear experiment, reduce the normal friction at the same time, and improve the experimental accuracy. It has good adaptability, and for samples with a certain size error, the close fit 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 a rock mass structure surface, belonging to the technical field of geotechnical engineering. Background technique [0002] There are generally weak structural planes such as joints, fissures, and weak layers in underground engineering rock mass. These structural planes control the strength and stability of rock mass and are crucial to engineering safety. Under the conditions of earthquake load, periodic storage and drainage of reservoir or mining of coal seam face, the rock mass is affected by cyclic shear load 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 to explore its failure mechanics mechanism and failure characteristics. ...

AI Technical Summary

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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