Stress-strain control type direct shear apparatus

Abstract

The invention provides stress-strain control type direct shear apparatus. The direct shear apparatus comprises a square shear box containing a rock-soil body sample, wherein the square shear box is composed of an upper shear box and a lower shear box. The upper end of the upper shear box is provided with a vertical pressure loading mechanism used for exerting a vertical load on the rock-soil body sample. One end of the lower shear box is matched with a horizontal shear loading mechanism used for a stress control type direct shear experiment, and the other end of the lower shear box is matched with a horizontal loading mechanism used for a strain control type direct shear experiment. The horizontal loading mechanism comprises a torque converting box arranged on an experiment platform and a horizontal loading tension and pressure sensor connected with the torque converting box and the lower shear box. The stress-strain control type direct shear apparatus not only can carry out the strain control type direct shear experiment, but also can carry out the stress control type direct shear experiment. The stress-strain control type direct shear apparatus is simple in structure, low in manufacturing cost, and easy to popularize in and apply to production and teaching.

Description

technical field [0001] The invention belongs to the field of geotechnical engineering, and in particular relates to a direct shear instrument, in particular to a stress-strain control multifunctional direct shear instrument. Background technique [0002] The direct shear instrument is the most conventional test equipment in geotechnical tests, and it is mainly used to measure the shear strength parameters of rock and soil under static load conditions. Most of the instability of rock and soil is caused by shear failure, and the instability and damage of geotechnical engineering are accompanied by the development of shear displacement. It is of great significance in the construction of geotechnical engineering to accurately measure the shear strength parameters of rock and soil, and the direct shear test is an important test method. [0003] The direct shear test is the earliest and most direct test method for determining the shear strength of rock and soil developed on the b...

AI Technical Summary

Problems solved by technology

During the test, it was found that the lever tilted to a large extent after the weight was applied, and the greater the applied load, the greater the inclination angle, reaching a maximum of 30°, which greatly reduced the actual pressure acting on the sample. It can be seen that using the lever Large loss of loading force of the mechanism

In addition, the shear cell has a single specification, especially the circular shear cell used in China, which is small in size and the stress concentration phenomenon is serious, so that the sample has been in a state of uneven stress distribution throughout the test process. With the generation of shear displacement, the inhomogeneity of this stress distribution will also increase, which will affect the test results

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