Failure transition of shear-to-dilation band of rock salt under triaxial stresses  

作　　者：Jianfeng Liu Xiaosong Qiu Jianxiong Yang Chao Liang Jingjing Dai Yu Bian 

机构地区：[1]State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu,610065,China [2]CNPC Key Laboratory of Oil and Gas Underground Storage Engineering,Langfang,065007,China [3]College of Water Resource and Hydropower,Sichuan University,Chengdu,610065,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第1期56-64,共9页岩石力学与岩土工程学报（英文版）

基　　金：This research was financially supported by the Science and Technology Department of Sichuan Province Project,China(Grant Nos.2022YFSY0007,2021YFH0010);the National Scientific Science Foundation of China(Grant No.U20A20266).

摘　　要：Great potential of underground gas/energy storage in salt caverns seems to be a promising solution to support renewable energy.In the underground storage method,the operating cycle unfortunately may reach up to daily or even hourly,which generates complicated pressures on the salt cavern.Furthermore,the mechanical behavior of rock salt may change and present distinct failure characteristics under different stress states,which affects the performance of salt cavern during the time period of full service.To reproduce a similar loading condition on the cavern surrounding rock mass,the cyclic triaxial loading/unloading tests are performed on the rock salt to explore the mechanical transition behavior and failure characteristics under different confinement.Experimental results show that the rock salt samples pre-sent a diffused shear failure band with significant bulges at certain locations in low confining pressure conditions(e.g.5 MPa,10 MPa and 15 MPa),which is closely related to crystal misorientation and grain boundary sliding.Under the elevated confinement(e.g.20 MPa,30 MPa and 40 MPa),the dilation band dominates the failure mechanism,where the large-size halite crystals are crushed to be smaller size and new pores are developing.The failure transition mechanism revealed in the paper provides additional insight into the mechanical performance of salt caverns influenced by complicated stress states.

关 键 词：Rock salt Cyclic mechanical loading Shear band Dilation band Underground gas storage(UGS) 

分 类 号：TU45[建筑科学—岩土工程]