Study on deformation characteristics and mechanical behavior of rock under low temperature freezing state

Abstract

Abstract: In order to study mechanical behaviorof frozen rock under different water content in frozen soil area, the uniaxial compression test and Brazilian splitting test of tuff and basalt frozen soil specimens at room temperature 20 ℃ and low temperature －20 ℃ were carried out. By observing its deformation behavior and acoustic emission activity, the fracture failure process and the effect of water content on the strength and deformation properties of the material were studied. The results showed,the fracture process of frozen rock can be divided into the following stages:Ⅰ stage is crack pore closure;Ⅱ stage is elastic deformation;Ⅲ stage is crack initiation and stable crack propagation;Ⅳ stage is unstable crack propagation. At the same time, the stress level at the beginning of stage Ⅲ increases with the increase of water saturation. The peak stress intensity and strain increase with the increase of water content, and the relationship between them can be approximated by a straight line. Rock brittleness decreases with the increase of water content, and the influence of indirect tensile strength on water content is more sensitive than uniaxial compressive strength.

Key words: frozen rock, water content, compressive strength, tensile strength, deformation, acoustic emission, failure process

CLC Number:

TB121

XI Xin-lin. Study on deformation characteristics and mechanical behavior of rock under low temperature freezing state[J]. Journal of Lanzhou University of Technology, 2022, 48(2): 21-27.

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