岩石结构的不稳定性和突跳现象

将结构稳定性理论和方法应用于岩石力学问题。分别采用2个简单的力学模型,研究竖井开挖过程中岩爆的发生和逆冲断层地震。通过理论研究,对于竖井开挖过程,分析无量纲孔壁位移和孔壁压力构成的平衡路径曲线;对于逆冲断层,分析远场无量纲位移和约束反力构成的平衡路径曲线。岩石结构失稳属于极值点型失稳,岩爆和逆冲断层地震是2种不同类型的极值点型失稳。从平衡路径曲线上来看,竖井开挖中的岩爆是一种应力极值点型失稳,伴随有位移突跳;而逆冲断层地震是一种位移极值点型失稳,并伴有力的突跳。

INSTABILITY AND SNAPPING PHENOMENON OF ROCK STRUCTURE

Theory of structure stability was applied for the problems of rock mechanics. Two simple models were adopted for the analysis of reversed fault earthquake and rockburst during shaft excavation，and their analytical solutions were obtained. The equilibrium path curve for the shaft excavation links the non-dimensional displacement with the pressure of borehole wall，while the equilibrium path curve for the reversed fault earthquake links the non-dimensional displacement at far-field with the constrained force. The instability of the rock structures was described as the instability at the point of maximum value. The rockbursts and reversed fault earthquake are two different kinds of instabilities. The rockburst during the shaft excavation is the instability occurred at the maximum stress and with a displacement jumping，while the reversed fault earthquake is the instability occurred at the maximum displacement with a force jumping.