Mechanical Properties of Metasandstone under Uniaxial Graded Cyclic Loading and Unloading

Abstract

The acoustic emission and wave velocity characteristics of metasandstone under graded cyclic loading and unloading were revealed by conducting graded cyclic loading and unloading tests. The results show that the acoustic emission signals of metasandstone samples are mainly generated in the loading phase, and almost no acoustic emission activity is generated in the unloading phase. The quiet period feature can be used to monitor and predict the destabilization of metasandstone. There is a stress threshold for wave velocity variation in metasandstone, below which wave velocity does not change significantly with increasing stress. When the stress exceeds this threshold, the wave velocity of the rock sample will decrease rapidly with the increase in stress. The phenomenon of a rapid decrease in wave velocity can be used to predict the damage instability of rock masses in engineering.

Keywords

• rock mechanics
• brittle rock
• uniaxial graded cyclic loading and unloading
• indoor tests
• acoustic emission
• wave velocity