Rock specimens for rock shear strength testing and test methods

Abstract

The present invention provides a rock sample used for rock shear strength testing. The body of the rock sample is a hollow cylinder with a coaxial cylindrical hole processed at the center, and a circle around the outer cylindrical surface is processed on the outer cylindrical surface of the hollow cylinder. For oblique grooves of equal structure, the section passing through the oblique groove and the section perpendicular to the central axis of the hollow cylinder form an inclination angle θ of 30° to 70°, and the center point of the section passing through the oblique groove coincides with the midpoint of the central axis of the hollow cylinder. The present invention also provides a method for testing rock shear strength based on the above-mentioned hollow cylindrical rock sample with an annular oblique groove. The rock sample is simple and convenient to process, has low requirements for test equipment, and can ensure uniform stress distribution. Shear failure occurs along the direction of the oblique groove during the rock compression process. Using this rock sample can quickly, simply and accurately obtain rock of shear strength.

Description

technical field [0001] The invention belongs to the technical field of rock material performance testing, in particular to a rock sample used for testing rock shear strength and a method for testing shear strength based on the sample. [0002] technical background [0003] The shear strength of rock refers to the ability of rock to resist shear failure. In actual engineering, rocks are usually in a complex state of stress, and the failure of engineering rock mass is often not simply crushed and cracked, but macro-shear failure often occurs. Therefore, the research on the shear strength of rock and its testing method has important theoretical value and engineering application value. At present, direct shear test, wedge shear test and triaxial test are mainly used to measure the shear performance of rock materials. The main advantage of the direct shear test is that it is simple and convenient, does not require special equipment, and the same sample can be reused to improve t...

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Problems solved by technology

However, this method has high requirements on the processing of the sample. If the processing of the cube sample is not precise enough, that is, the shape of the cube is irregular, it will cause uneven stress distribution on the shear surface, and stress concentration will occur, causing the sample to not follow the predetermined direction. The shear plane is damaged, failing to meet the requirements of the shear test

Triaxial test is a good method to test the shear strength of rock, but the equipment is expensive and the test time is long, so the promotion of this method is limited

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