Investigation of the influence of intermediate principal stress on the dynamic responses of rocks subjected to true triaxial stress state

作     者：Wei You Feng Dai Yi Liu Hongbo Du Ruochen Jiang Wei You;Feng Dai;Yi Liu;Hongbo Du;Ruochen Jiang

作者机构：State Key Laboratory of Hydraulics and Mountain River EngineeringCollege of Water Resource and HydropowerSichuan UniversityChengdu 610065China 

出 版 物：《International Journal of Mining Science and Technology》 (矿业科学技术学报（英文版）)

年 卷 期：2021年第31卷第5期

页      面：913-926页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 0808[工学-电气工程] 08[工学] 080104[工学-工程力学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0807[工学-动力工程及工程热物理] 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 financial support from the National Natural Science Foundation of China(Nos.52039007 and 52009086) the Sichuan Province Youth Science and Technology Innovation Team(No.2020JDTD0001)。 

主　　题：Triaxial Hopkinson bar Intermediate principal stress Dynamic strength Failure modes Numerical simulation True triaxial stress 

摘      要：Precisely understanding the dynamic mechanical properties and failure modes of rocks subjected to true triaxial stress state(σ1σ2σ3,whereσ1,σ2,andσ3 are the major principal stress,intermediate principal stress,and minor principal stress,respectively)is essential to the safety of underground engineering.However,in the laboratory,it is difficult to maintain the constant true triaxial stress state of rocks during the dynamic testing process.Herein,a numerical servo triaxial Hopkinson bar(NSTHB)was developed to study the dynamic responses of rocks confronted with a true triaxial stress state,in which lateral stresses can maintain constant.The results indicate that the dynamic strength and elastic modulus of rocks increase with the rise of intermediate principal stressσ2,while the dynamic elastic modulus is independent of the dynamic strain rate.Simulated acoustic emission distributions indicate that the intermediate principal stressσ2 dramatically affects dynamic failure modes of triaxial confined rocks.Asσ2 increases,the failure pattern switches from a single diagonal shear zone into two parallel shear zones with a small slant.Moreover,a recent triaxial Hopkinson bar experimental system using three bar pairs is also numerically established,and the measuring discrepancies are identified between the two numerical bar systems.The proposed NSTHB system provides a controllable tool for studying the dynamic triaxial behavior of rocks.