不同初始损伤程度下循环加卸围压对岩石劣化及渗流特性的影响研究  

Study on the influence of cyclic confining pressure on rock deterioration and seepage characteristics under different initial damage degrees

作　　者：张培森[1,2] 许大强 颜伟[1,2] 胡昕 张晓乐 董宇航 方家鑫 ZHANG Peisen;XU Daqiang;YAN Wei;HU Xin;ZHANG Xiaole;DONG Yuhang;FANG Jiaxin(National Key Laboratory for Mine Disaster Prevention and Control,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;National Demonstration Center for Experimental Mining Engineering Education,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;Northwest Electric Power Design Institute Co.Ltd.of China Power Engineering Consulting Group,Xi’an,Shaanxi 710075,China)

机构地区：[1]山东科技大学矿山灾害预防控制国家重点实验室培育基地,山东青岛266590 [2]山东科技大学矿业工程国家级实验教学示范中心,山东青岛266590 [3]中国电力工程顾问集团西北电力设计院有限公司,陕西西安710075

出　　处：《岩石力学与工程学报》2023年第9期2109-2124,共16页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点研发计划(2018YFC0604702);国家自然科学基金资助项目(51379119);山东省自然科学基金项目(ZR2021ME086)。

摘　　要：为探究巷道围岩劣化损伤规律,明晰巷道片帮突水机制,基于Rock Top多场耦合试验仪对砂岩开展常规三轴(C组)、不同初始损伤程度下常规卸围压(W组)及循环加卸围压(X组)3种应力路径下的岩石劣化、渗流特性室内试验。结果表明:(1)X组岩石循环加卸围压初始,岩石轴向变形较侧向及体积变形发展缓慢,但循环加卸围压可导致岩石发生“应变累积”,使得X组岩石应力跌落点较W组出现“滞后”现象;(2)初始损伤明显影响岩石强度及对围压的敏感性,X,W组岩石初始损伤程度均与统一围压降参数(η)呈负相关,与应变围压增量比(λ_(i))呈正相关,其中,X组岩石η均小于W组,λ_(i)均大于W组;(3)X,W,C组岩石均发生了明显脆性破坏,破坏形态均以剪切破坏为主,初始损伤程度较低时,X组岩石破坏程度较大,并伴随有局部宏观裂纹出现;(4)岩石渗透率受制于岩石孔隙、骨架结构及裂纹拓展发育等因素影响,X,W组岩石渗流–应变关系曲线均可分为3个阶段,一、三阶段相一致,二阶段X组岩石渗透率整体呈先波动下降后波动上升,W组岩石渗透率整体呈波动上升;(5)X组岩石渗透率波动变化随循环等级增大而趋于明显,初始损伤程度越高,该现象越易出现,循环次数对此规律影响较小,但循环次数增加对岩石渗流起抑制作用,并且该抑制作用较围压降低导致的促进作用更为显著。In order to explore the law of deterioration and damage of roadway surrounding rocks and to clarify the water inrush mechanism of roadway spalling,laboratory tests on deterioration and seepage characteristics of sandstone under three stress paths of conventional triaxial(group C),conventional discharge of confining pressure(group W)under different initial damage degrees,and cyclic loading and unloading confining pressure discharge(group X)were carried out based on Rock Top multi-field coupling tester.The results show that:(1)At the beginning of cyclic loading and unloading confining pressure of group X rocks,the axial deformation of rocks is slower than the lateral and volume deformation,but cyclic loading and unloading confining pressure can lead to"strain accumulation"of rock,which makes the stress drop point of rock in group X appears"hysteresis effect"compared with group W.(2)The initial damage significantly affects the rock strength and the sensitivity to the confining pressure.The initial damage degree of rocks in group X and group W is negatively correlated with the unified confining pressure drop parameter(n),and positively correlated with the incremental ratio of the strain and the confining pressure(λ_(i)).The parameter n of group Xis smaller than that ofthe group W,whileλ_(i)is greater than that of the group W.(3)Obvious brittle failure of rocks occurs in groups X,group W and group C,and the main failure mode is shear failure.When the initial damage degree is low,the rock failure degree of group X is large,accompanied by local macroscopic cracks.(4)The rock permeability is affected by the factors such as rock pores,framework structure and crack development.The rock seepage-strain relationship curves of groups X and group W can be divided into three stages.The first and third stages are consistent.In the second stage,the rock permeability of group X decreases first and then increases,while the rock permeability of group W increases as a whole.(5)The permeability fluctuation of group X tends to be obvi

关 键 词：岩石力学 初始损伤 循环加卸围压 岩石劣化损伤 渗流特性 

分 类 号：TU45[建筑科学—岩土工程]