Beijing Key Laboratory of Urban Underground Space Engineering;
Department of Civil Engineering;
School of Civil and Resource Engineering;
University of Science and Technology Beijing;
Beijing;
100083;
China;
State Key Laboratory for GeoMechanics and Deep Underground Engineering;
China University of Mining and Technology;
Beijing;
100083;
China;
Institute of Acoustics;
Chinese Academy of Sciences;
Beijing;
100190;
China;
Fatigue loading; Confining stress unloading; Unloading rate; Energy evolution; Computed tomography(CT)scanning;