水-岩耦合作用下红砂岩应变率效应研究  

Research on Strain Rate Effects of Red-sandstone under Water-rock Coupling

作　　者：郑广辉[1] 许金余[1,2] 王鹏[1] 刘石[1] 王浩宇[1] 

机构地区：[1]空军工程大学机场建筑工程系,西安710038 [2]西北工业大学力学与土木建筑学院,西安710072

出　　处：《地下空间与工程学报》2017年第1期79-85,共7页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51378497)

摘　　要：基于100 mm SHPB试验平台,对吸水红砂岩试样进行不同应变率下冲击压缩试验,对比干燥试样试验结果,探究了水-岩耦合作用下动态抗压强度、变形及单元可释放弹性应变能We的应变率相关性,得出:在水-岩-动力的耦合中,岩石强度的应变率强化作用和水的劣化作用同时存在,但应变率强化作用占主导地位;裂隙水对岩石强度的应变率效应有强化作用,并且这种强化作用随着应变率的增大而增强;岩石的峰值应变在水的耦合作用下应变率效应更为显著;当应变率超过某一阈值时,吸水试样在弹性变形阶段更加容易变形,弹性模量降低,而在冲击作用下,裂隙水阻碍裂纹发展,试样抵抗变形的能力增强,变形模量线性增加;水-岩耦合作用下We对应变率更为敏感,与干燥试样的WDe相比,WWe随着应变率的增加而增长更为迅速。Impact compressive experiments with different stain rates on dried and waterish sandstone samples were conducted with the modified 100 mm split Hopkinson pressure bar（ SHPB） apparatus. The strain rate effect of dynamic compress strength as well as deformation and energy release ‘We＇ under water-rock coupling were analysed. It is demonstrated that,the strengthening effect caused by strain rate and the deterioration effect caused by water exist in the strength of rock simultaneously,and the strengthening effect plays the dominate role; The strain rate effect of rock strength is enhanced by fissure water,and the influence increases with the increase of strain rate; The effect of strain rate of peak strain is more significant under the action of water coupling; When strain rate exceeds a certain threshold, waterish samples in elastic stage are more easy deformation, and the elastic modulus decreases. However,the ability of rock resisting deformation is enhanced in the phase of crack development,and the deformation modulus increases linearly as the result of crack development is hindered by fissure water under impact. Weunder water-rock coupling is more sensitive to strain rate,and WWeincreases more rapidly with the increase of strain rate compared with WDeof dry sample.

关 键 词：岩石力学 水-岩耦合 应变率效应 SHPB试验 

分 类 号：TU451[建筑科学—岩土工程]