真三轴循环主应力作用下砂岩能量演化规律  

Energy evolution of sandstone under true triaxial cyclicprincipal stress

作　　者：赵光明[1,2] 刘之喜 孟祥瑞[1,2] 张若飞[1,2] 顾清恒 戚敏杰 ZHAO Guang-ming;LIU Zhi-xi;MENG Xiang-rui;ZHANG Ruo-fei;GU Qing-heng;QI Min-jie(State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan,Anhui 232001,China;Key Laboratory of Safe and Effective Coal Mining,Ministry of Education,Anhui University of Science and Technology,Huainan,Anhui 232001,China)

机构地区：[1]安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室,安徽淮南232001 [2]安徽理工大学煤矿安全高效开采省部共建教育部重点实验室,安徽淮南232001

出　　处：《岩土力学》2023年第7期1875-1890,共16页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51974009);安徽省科技重大专项(No.202203a07020011);安徽省“特支计划”的领军人才项目(No.T000508);高校协同创新项目(No.GXXT-2021-075);安徽省学术和技术带头人科研活动经费;淮北市重大科技专项(No.Z2020005)。

摘　　要：为了探究真三轴主应力循环加卸载对砂岩能量积聚与耗散的影响,利用自主研发的真三轴扰动卸荷岩石测试系统进行了3个主应力循环加卸载试验。基于真三轴循环加卸载应力-应变演化规律与加卸载特征,划分了主应力循环加卸载试验中加载、卸载的种类;通过对三向主应力循环加卸载过后岩体表面裂纹对比分析,发现最小主应循环对岩体产生损伤最大,中间主应力次之,最大主应产生损伤最小;利用图形面积积分法与叠加法分别计算了真三轴循环加卸载的弹性能密度、耗散能密度与输入能密度,分析了三者随主应力次数增加的演化规律与加卸载过程中的能量分配;利用真三轴同时加卸载试验,验证了上述提出的能量分析方法的合理性与准确性,对其3个主应力方向卸载释放弹性能密度分析,发现循环加卸载产生的损伤对岩体储存弹性能密度影响较小。对比了3个主应力卸载对砂岩损伤与能量耗散的影响,对巷道掘进方向进行了进一步讨论。To explore the influence of true triaxial cyclic loading and unloading in principal stress directions on sandstone energy accumulation and dissipation,three cyclic loading and unloading tests in principal stress directions were carried out by using the self-developed true triaxial disturbed unloading rock testing system.Based on the stress-strain evolution law and the loading and unloading characteristics of true triaxial cyclic loading and unloading tests,the types of loading and unloading in the cyclic loading and unloading tests are classified.Through the comparative analysis of the surface cracks of rock mass after cyclic loading and unloading in three principal stress directions,it is found that the minimum principal stress cycle causes the severest damage to rock mass,followed by the intermediate principal stress,and the maximum principal stress causes the least damage.The elastic energy density,dissipated energy density,and input energy density of true triaxial cyclic loading and unloading are calculated by using the graph area integral method and the superposition method,respectively.The evolution laws of the above three densities with the increase of the number of principal stresses and the energy distribution during loading and unloading are analyzed.The rationality and accuracy of the proposed energy analysis method are verified by the true triaxial loading and unloading test,and the elastic energy released by unloading in three principal stress directions is analyzed.The damage caused by cyclic loading and unloading has little influence on the elastic energy stored in the rock mass.The influences of unloading independently in three principal stress directions on sandstone damage and energy dissipation are compared,and the advancing direction of the roadway is further discussed.

关 键 词：岩石力学 真三轴循环加卸载 能量积聚 能量耗散 加卸载分类 能量演化 

分 类 号：TU451[建筑科学—岩土工程]