The influence of moisture content on the acoustic emission at threshold of rock destruction

Abstract

Investigations of rocks with different moisture contents demonstrate that during the process of failure, the number of acoustic emissions (AE) increases in the vicinity of the yield point with the rapid generation and growth of micro cracks. The increase of moisture content leads to decreased rock strength and fewer events of AE, which suggests that the inner structure and mechanical properties of the rocks are changed. Moreover, less energy is released during the process of destruction, which exhibits little influence on the stress level at the threshold point of yield. One could use the variation of rock AE to obtain the end stress of rock elastic stage and Poisson's ratio. And the stress ratio at the critical point could be described by mathematical expressions.