一维动静组合加载下砂岩动力学特性的试验研究  

EXPERIMENTAL STUDY OF DYNAMIC CHARACTERISTICS OF SANDSTONE UNDER ONE-DIMENSIONAL COUPLED STATIC AND DYNAMIC LOADS

作　　者：宫凤强[1,2,3] 李夕兵[1,2] 刘希灵[1,2] ZHAO J 

机构地区：[1]中南大学资源与安全工程学院,湖南长沙410083 [2]中南大学深部金属矿产开发与灾害控制湖南省重点实验室,湖南长沙410083 [3]瑞士洛桑联邦理工大学岩石力学实验室,洛桑CH-1015,瑞士1

出　　处：《岩石力学与工程学报》2010年第10期2076-2085,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2010CB732004);国家自然科学基金资助项目(50934006);中南大学优秀博士学位论文扶植资助项目(2008yb001);中国科协科技导报社博士生创新研究计划资助项目(kjdb20090102-3)

摘　　要：基于对深部岩石承受高地应力并在动力开挖扰动下发生破坏这一问题的科学认识,利用改造的劈裂霍普金森压杆动静组合加载试验装置,开展一维动静组合加载下砂岩的动力学特性试验研究。选取无轴压和3个典型轴压水平4种情形,开展不同应变率下的冲击试验。研究结果表明,相同应变率下岩石对外界冲击的响应受轴压比影响很大,冲击强度会随着轴压比的增加出现先增加后减小的趋势,在轴压比为0.6～0.7时达到最大值。相同轴压下,冲击强度会随着应变率的增加而增加,呈现指数函数关系。在一定的轴压比范围内,随着入射能的递增,岩石在加载破坏试验中先后会经历"吸收能量-释放能量-吸收能量"3个阶段。这3个阶段可以较好的解释高应力下岩石的动态强度递增、岩爆发生和诱导致裂三者之间的互相转化机制,对深部岩石工程的实践可以提供理论上的指导。Based on the scientific understanding of deep rock under high in-situ stress and dynamic excavation disturbance,the experiments on dynamic failure characteristics of sandstone under one-dimensional coupled static and dynamic loads were conducted with a modified split Hopkinson pressure bar（SHPB）.Four cases,without axial pre-compressive stress and with three levels of axial pre-compressive stress,were designed to conduct impact tests under different strain rates.The results show that,at the same strain rate,the dynamic response of rock is influenced obviously by axial pre-compressive stress ratio.When the strain rate is a constant,the impact compressive strength first increases and then decreases as the axial static pre-stress increases;and it reaches the maximum value when the axial pre-compressive stress ratio is 0.6-0.7.When the axial static pre-stress is a constant,the impact compressive strength increases with an exponential function as the strain rate increases.Within a certain range of axial pre-compressive stress ratios,the incident energy will influence the dynamic impact energy response of rock specimen;and the specimen will experience three phases of absorb energy-release energy-absorb energy when the axial compressive stress ratio increases.The transformation mechanism of dynamic strength increase,rock burst and induced fracture of rock under high in-situ stress can be explained better by the above three phases.The results can also provide a theoretical guide for the deep rock engineering practice.

关 键 词：岩石力学 深部岩石 动静组合加载 劈裂霍普金森压杆 动态压缩强度 岩爆 诱导致裂 

分 类 号：TU45[建筑科学—岩土工程]