Unilateral unloading test device for brittle rock in biaxial stress state and test method of unilateral unloading test device

Abstract

The invention discloses a unilateral unloading test device for brittle rock in a biaxial stress state and a test method of the unilateral unloading test device. The device comprises a two-axis servo control real-time loading and unloading system, a stress-strain monitoring system, an automatic control and data acquisition system, an acoustic emission monitoring system and a portable image acquisition and analysis system, wherein a confining pressure state in a stratum under certain conditions as well as a unilateral excavation unloading operating condition of an underground cavern in a construction process can be simulated; the overall stress-strain level of a rock sample is recorded by the stress-strain monitoring system; a local unilateral unloading rate is controlled and fed back by the automatic control and data acquisition system; the acoustic emission monitoring system and the portable image acquisition and analysis system monitor crack initiation, expansion, opening and closing features of cracks in a unilateral unloading region and an influence domain of the unilateral unloading region in the whole process and observe and analyze a formation and expansion mechanism of the cracks, and theoretical basis and experimental basis are provided for research of cavern side wall splitting failure caused by excavation unloading.

Description

technical field [0001] The invention relates to a unilateral unloading test device and a test method thereof under the biaxial stress state of a brittle rock mass. Background technique [0002] With the development and construction of large-scale water conservancy and hydropower, nuclear power underground projects and tunnel and slope projects in China, a large number of excavation problems of high and steep slopes and large underground caverns have been encountered in engineering practice. In essence, excavation and unloading is the process of concentrated release of in-situ stress. Compared with the loading condition, the mechanical properties of the rock mass are significantly different under the condition. Especially for large-area unloading, engineering rock mass exhibits complex mechanical characteristics due to the large amount of ground stress release, high level of unloading, and wide range of influence. In view of the ubiquity of deformation and failure of rock ma...

AI Technical Summary

Problems solved by technology

[0005] The present invention is a unilateral unloading test device and a test method thereof under the biaxial stress state of brittle rock mass, and aims at overcoming the defects and deficiencies of the traditional rock sample unloading test device

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