Test methods for acquiring thick wall cylinder sample ring fracture

Abstract

The invention relates to a test method for obtaining ring fracture of a cylinder sample with thick wall. The method comprises the following steps: firstly, sampling is carried out to testing rock mass objects; the rock mass which is obtained by sampling is made into the cylinder sample with thick wall; a certain axle load is applied to the cylinder sample with thick wall so as to lead the sample and an upper rigid loading end part and a lower rigid loading end part to contact closely; oil is filled into inner holes of the cylinder sample with thick wall, and into gaps between the cylinder sample and a load chamber; three axles of inner pressure, confining pressure and axle pressure of the cylinder sample with thick wall are loaded to a designed pressure value so as to lead the top, the bottom, the inner hole wall and the outer wall of the cylinder sample with thick wall are respectively in pressure state; the axial loading of three-directional loading is kept to be constant; and unloading is carried out to the cylinder sample with thick wall till the test sample is damaged. Three axles test is carried out to the cylinder sample with thick wall by loading and unloading so as to obtain the ring fracture results of the cylinder sample with thick wall, which is similar with the subarea fracture phenomenon occurring when the deep rock mass is excavated, therefore, the subarea fracture research is carried out, and corresponding measures need to be adopted for solving the problem that the subarea fracture phenomenon occurs when the deep rock is excavated.

Description

technical field [0001] The invention relates to a test method for obtaining annular fracture of a thick-walled cylindrical sample, and is especially suitable for experiments in simulating the annular fracture process of deep rock excavation engineering, and also suitable for experiments in simulating the annular fracture process of brittle materials such as concrete. Background technique [0002] Many scholars at home and abroad have discovered a phenomenon of zonal fractures in the destruction of surrounding rocks in deep mines. The so-called zonal fracture refers to the phenomenon that when a roadway is excavated in a deep rock mass, the surrounding rock around the roadway will produce alternate fractured areas and unfractured areas. As early as 1980, there was a report in South Africa about the zonal fracture phenomenon in the roadway roof at a depth of 2000m to 3000m in the Witwatersrand gold mine, and a similar phenomenon also appeared in the Маяк mine in Russia. It sh...

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