Experimental study on failure evolution mechanism of clastic rock considering cementation and intermediate principal stress  

作　　者：Feiyan Wang Xia-Ting Feng Yangyi Zhou Xiaojun Yu 

机构地区：[1]Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,School of Resources and Civil Engineering,Northeastern University,Shenyang,110819,China [2]Key Laboratory of Liaoning Province on Deep Engineering and Intelligent Technology,Northeastern University,Shenyang,110819,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2023年第7期1636-1650,共15页岩石力学与岩土工程学报（英文版）

基　　金：financial support from the 111 Project(Grant No.B17009);the Liaoning Revitalization Talents Program(Grant No.XLYCYSZX1902).

摘　　要：The study of clastic rock failure evolution under true triaxial stress is an important research topic;however,it is rarely studied systematically due to the limitation of monitoring technology.In this study,true triaxial compression tests were conducted on clastic rock specimens to investigate the effect of cementation and intermediate principal stress(s2)on the failure mechanism.The complete stressestrain curves were obtained,while the acoustic emission(AE)was monitored to indirectly evaluate the evo-lution of tensile and shear cracks,and crack evolution under true triaxial compression was imaged in real time by a high-speed camera.The results showed that the deformation and failure characteristics of clastic rock were closely related to the cementation type and intermediate principal stress.On the basis of the distribution characteristics of the ratio of rise time to amplitude(RA)and the average frequency(AF)of AE signals,tensile cracks of the contact cementation specimen propagated preferentially.Meanwhile,the enhancement of specimen cementation promoted the evolution of shear cracks,and the increase inσ_(2)promoted the evolution of tensile cracks.Moreover,the mesoscale cracking mechanism of clastic rock caused by cementation andσ_(2)under true triaxial compression was analyzed.The failure patterns of clastic rock under true triaxial compression were divided into three modes:structure-induced,structure-stress-induced and stress-induced failures.This study confirms the feasibility of high-speed camera technology in true triaxial testing,and has important implications for elucidating the disaster mechanism of deep tunnels in weak rocks.

关 键 词：True triaxial compression CEMENTATION Failure evolution Acoustic emission(AE) High-speed camera 

分 类 号：TD325[矿业工程—矿井建设]