不同加载率下水饱和砂岩的力学特性研究  

Mechanical properties of saturated sandstone under different loading rates

作　　者：周子龙[1] 蔡鑫[1] 周静[1] 程瑞山 ZHOU Zilong;CAI Xin;ZHOU Jing;CHENG Ruishan(School of Resources and Safety Engineering,Central South University,Changsha,Hunan 410083,China)

机构地区：[1]资源与安全工程学院中南大学

出　　处：《岩石力学与工程学报》2018年第A02期4069-4075,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家基础研究计划项目(2015CB060200);国家自然科学基金资助项目(41772313);中南大学研究生自主探索创新项目(2018zzts210)~~

摘　　要：为揭示水和加载率对岩石力学性质的共同作用效应,利用分离式霍普金森压杆试验系统对干燥和饱水砂岩进行一系列动态压缩、劈裂及断裂试验。试验结果表明,在静态加载条件下,岩石饱水后其强度和断裂韧度均会发生不同程度的降低;在动态加载条件下,岩石的强度和断裂韧度随着加载率的增加而升高,且相较于干燥试样,饱和岩石表现出更高的率相关性。在较高加载率下,岩石内部的自由水可产生惯性效应、弯液面效应以及黏性作用,阻碍裂纹的产生和扩张。特别地,当加载率超过1290GPa/s后,饱和试样的压缩强度甚至可以超过干燥试样。To investigate the combined effects of water saturation and loading rate on rock mechanics,a series of dynamic compression,tension and fracture tests are conducted on both dry and saturated sandstone specimens using the split Hopkinson pressure bar(SHPB) system. Test results show that,under static loads,both strength and fracture toughness have different degrees of reduction after the specimen was saturated. Under dynamic loads,the strength and fracture toughness increase with the increase of loading rate,and the saturated specimen has higher rate dependences for each mechanical property compared with that of dry ones. Under high loading rates,free water inside the rock specimen can induce inertial effect,meniscus effect and viscosity effect,which prevent the initiation and propagation of cracks. Particularly,when the loading rate exceeds 1 290 GPa/s,the compressive strength of saturated specimen can even be greater than that of dry specimen.

关 键 词：岩石力学 水饱和 砂岩 SHPB 岩石动力学 率相关性 

分 类 号：TU45[建筑科学—岩土工程]