【摘要】 基于SHPB装置,设计了岩石动静组合加载试验系统。根据SHPB装置的理论基础,即弹性杆中一维应力波传递及试件应力均匀化,系统阐述了基于SHPB装置岩石在动静组合加载下的适用性,并针对高放废物地质处置新疆预选区天湖地段的钻孔花岗岩岩芯,开展了一系列的动静组合加载试验。动静组合拉伸加载下,随着轴向静压的增大,岩石的抗冲击强度呈现出先增大的趋势。大约在静载抗拉强度的50%时,抗冲击拉伸强度达到最大值。并且,随着轴向静压的增大,岩石的动静组合拉伸强度亦随之快速增大,最大可达到静载强度的3倍,抗冲击动载的1.5倍。试验结果表明,在冲击破坏情况下,岩石组合加载破坏模式呈现拉伸破坏,与静态拉伸破坏及一般冲击下的劈裂破坏特征基本一致。通过系列的动静组合拉伸加载,能够得到不同轴向静压及不同冲击动载下,岩石承受的临界动载荷值,进而可以确定一个施加动载荷大小的安全范围,这对于深部地下工程的爆破开挖,具有一定的理论指导意义。更多还原

【Abstract】 Based on the SHPB( Split Hopkinson Pressure Bar) installation,the coupled static and dynamic loading system for the rock is designed. According to the basic principle of the SHPB,i.e. the one dimensional stress wave propagation and the uniformity of the specimen,the coupled system for the rock has been illuminated in detail. In Tianhu area Xinjiang Uygur Autonomous Region,which is a preselected area for the HLW( High Level radioactive Waste) geological disposal,the rock core from the borehole a series of coupled static and dynamic loading has been carried out. With the precompression stress increase,the impact dynamic strength is increased. It could reach maximum when the precompression stress is about 50% of the static tension strength. Meanwhile,with the precompression stress increase,the coupled static and dynamic strength is increased obviously,especially it could reach about three times of static precompression stress,and about one and half times of the dynamic strength. The testing results show that the failure model of the coupled static and dynamic loading gives also tension failure,which is the same as the static tension and conventional dynamic loading test. Through a series of coupled static and dynamic loading,the strength of the rock specimen could be obtained under different kinds of precompression stress and dynamic loading,and then the safety range period of the dynamic loading could be confirmed,which is useful for the blasting and excavation of the deep geo-engineering.更多还原