盐岩三轴间隔疲劳特性试验研究  

Experimental study of triaxial interval fatigue of salt rock

作　　者：李宗泽 姜德义 范金洋[1] 陈结[1] 刘伟[1] 吴斐[1] 杜超[1] 康燕飞[1] LI Zong-ze;JIANG De-yi;FAN Jin-yang;CHEN Jie;LIU Wei;WU Fei;DU Chao;KANG Yan-fei(State Key Laboratory for the Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing,400044,China)

机构地区：[1]重庆大学,煤矿灾害动力学与控制国家重点实验室,重庆400044

出　　处：《岩土力学》2020年第4期1305-1312,1322,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51834003,No.41672292,No.41702309,No.51904039)。

摘　　要：为研究地下盐穴储气库受间歇性周期注、采循环载荷作用下围岩的非连续疲劳破坏演化过程,对取自巴基斯坦的深层盐岩进行了室内三轴间隔疲劳试验研究,并分析了三轴状态下不同围压、不同应力等级对盐岩间隔疲劳的影响。试验结果表明:(1)与单轴间隔疲劳相比,围压的存在不仅提高了盐岩的抗压强度,而且增加了盐岩的疲劳寿命,围压越高增加的幅度越明显。(2)三轴间隔疲劳试验中,盐岩间隔后循环中的残余应变大于间隔前的残余应变。这与单轴间隔疲劳得到的结果一致,但围压的上升会导致盐岩的残余变形积累速度以及间隔前后循环残余的变形差值都减小。(3)随着应力等级的升高,残余应变以及时间间隔前后的残余应变差值都呈现增大的趋势。In order to study the discontinuous fatigue failure evolution process of surrounding rock of underground salt cavern gas storage under intermittent cyclic loads of injection and production,triaxial interval fatigue tests on deep salt rock from Pakistan was carried out,and the effects of confining pressure and stress level on the interval fatigue of salt rock under triaxial condition were analyzed.The results show that:Compared with uniaxial interval fatigue,confining pressure not only improves the compressive strength of salt rock specimens,but also increases the fatigue life of salt rock.The higher confining pressure results in a more significant increase in range.In triaxial interval fatigue tests,the residual strain of the stress cycles after intervals is larger than that before the interval,which is consistent with the results from uniaxial interval fatigue tests.However,the increase of confining pressure will lead to a decrease in the residual strain accumulation and the residual deformation difference between the cycles before and after the interval.With the increase of stress level,the residual strain and the difference of residual strain before and after time interval both show an increasing trend.

关 键 词：盐岩 间隔疲劳 围压 循环荷载 

分 类 号：TU452[建筑科学—岩土工程]