State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining&Technology Xuzhou 221116 ChinaSchool of Transportation Engineering Jiangsu Vocational Institute of Architectural Technology Xuzhou 221116 China;
State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining&Technology Xuzhou 221116 China;
Rock mechanics; Damage; Re-loading; Strength characteristics; Strain hardening;