Comparative experimental studies of acoustic emission characteristics of sandstone and mudstone under the impacts of cyclic loading and unloading

Guangming Zhao,Dongxu Liang,Chao Wang

doi:10.1177/1550147718795552

Abstract

In this article, the acoustic emission tests of uniaxial cyclic load imposed on or released from the sandstone and mudstone were carried out. The deformation and failure characteristics and the law governing the acoustic emission activity were studied. The results of the study show that (1) the variation of acoustic emission events of sandstone and mudstone is law governed and is in agreement with the tendency of stress and strain curve development. (2) The acoustic emission activity of mudstone is most active before peak stress, while sandstone is at peak stress. For the sandstone, when the number of acoustic emission events is the most active, the corresponding acoustic emission energy is not the largest. However, the peak value of acoustic emission events and the peak energy of the mudstone coincide, and the acoustic emission events get to the most intense due to the peak energy. (3) The acoustic emission activity is more severe when a load is imposed on or released from the rock. Compared to loading, the rock damage caused by unloading is even greater. (4) The acoustic emission event at the splitting point is more concentrated. The line of acoustic emission point is basically consistent with the shape of the split.

Highlights

In the engineering work involved in tunneling, subway excavation, slope leveling, and water conservation project construction, the study of the processes of deformation-induced instability and failure is of great significance
acoustic emission (AE) experiments were conducted with sandstone and mudstone by uniaxial cyclic loading and unloading and analyzed the AE feature differences monitored in the process of sandstone and mudstone damage
The major conclusions are drawn as follows: 1. In case of mudstone, the peak value of AE events does not coincide with the peak value of stress

Summary

Introduction

In the engineering work involved in tunneling, subway excavation, slope leveling, and water conservation project construction, the study of the processes of deformation-induced instability and failure is of great significance. Keywords Sandstone, mudstone, acoustic emission, cyclic loading and unloading, failure process We conduct AE experiments in sandstone and mudstone with specimens under uniaxial cyclic loading and unloading.

Results

Conclusion