Effect of fatigue loading-confining stress unloading rate on marble mechanical behaviors: An insight into fracture evolution analyses

作     者：Yu Wang Dongqiao Liu Jianqiang Han Changhong Li Hao Liu Yu Wang;Dongqiao Liu;Jianqiang Han;Changhong Li;Hao Liu

作者机构：Beijing Key Laboratory of Urban Underground Space EngineeringDepartment of Civil EngineeringSchool of Civil and Resource EngineeringUniversity of Science and Technology BeijingBeijing100083China State Key Laboratory for GeoMechanics and Deep Underground EngineeringChina University of Mining and TechnologyBeijing100083China Institute of AcousticsChinese Academy of SciencesBeijing100190China 

出 版 物：《Journal of Rock Mechanics and Geotechnical Engineering》 (岩石力学与岩土工程学报（英文版）)

年 卷 期：2020年第12卷第6期

页      面：1249-1262页

核心收录：

学科分类：08[工学] 0818[工学-地质资源与地质工程] 080104[工学-工程力学] 0815[工学-水利工程] 0813[工学-建筑学] 0814[工学-土木工程] 0801[工学-力学（可授工学、理学学位）] 

基　　金：The authors would like to thank the editors and the anonymous reviewers for their helpful and constructive comments.This study was supported by National Key Technologies Research&Development Program(Grant No.2018YFC0808402) State Key Laboratory for GeoMechanics and Deep Underground Engineering,China University of Mining and Technology(Grant No.SKLGDUEK1824) the Fundamental Research Funds for the Central Universities(Grant No.FRF-TP-20-004A2) 

主　　题：Fatigue loading Confining stress unloading Unloading rate Energy evolution Computed tomography(CT)scanning 

摘      要：Rocks in underground works usually experience rather complex stress *** this,their fracture mechanism is significantly different from rocks subjected to conventional triaxial compression *** effects of stress disturbances on rock geomechanical behaviors under fatigue loading conditions and triaxial unloading conditions have been reported in previous ***,little is known about the dependence of the unloading rate on fatigue loading and confining stress unloading(FL-CSU)conditions that influence rock *** this paper,we aimed at investigating the fracture behaviors of marble under FL-CSU conditions using the post-test X-ray computed tomography(CT)scanning technique and the GCTS RTR 2000 rock mechanics *** show that damage accumulation at the fatigue stage can influence the final fracture behaviors of *** stored elastic energy for rock samples under FL-CSU tests is relatively larger compared to those under conventional triaxial tests,and the dissipated energy used to drive damage evolution and crack propagation is larger for FL-CSU *** FL-CSU tests,as the unloading rate increases,the dissipated energy grows and elastic energy *** scanning after the test reveals the impacts of the unloading rate on the crack pattern and a fracture degree index is therein defined in this context to represent the crack *** shows that the crack pattern after FL-CSU tests depends on the unloading rate,and the fracture degree is in agreement with the analysis of both the energy dissipation and the amount of energy *** effect of unloading rate on fracture evolution characteristics of marble is revealed by a series of FL-CSU tests.