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为研究盐岩的动力特性和破坏特征,利用带围压的分离式Hopkinson压杆(SHPB)试验装置,对盐岩进行不同围压(5,15和25 MPa)下的冲击试验,并基于能量耗散原理来研究盐岩动态力学性能以及破坏特征,分析整个试验过程中的能量传递与转化,探究围压和输入能量对试件吸能及破坏的影响。研究结果表明:在同一围压下,随着入射能的增加,盐岩硬化效应越明显,表现为能量反射率增高而透射能和吸收能降低;在相同或相近的入射能下,随着围压的升高盐岩的流塑性变得越明显,但在动力荷载下盐岩由流塑性向脆性转变,最后发生脆性破坏;随着吸收能的增加,盐岩的峰值应力因围压不同而表现出不同的变化趋势,低围压时,吸收能越大,峰值应力越高,而高围压时,吸收能越大,峰值应力却越小;在有围压状态下,盐岩的冲击破坏形态与其他的脆性岩石相似,但在破坏机制上存在很大差异。
In order to study the dynamic characteristics and failure characteristics of salt rock, the impact tests of salt rock under different confining pressures (5, 15 and 25 MPa) were carried out by using the split Hopkinson pressure bar (SHPB) Dissipative principle to study the dynamic mechanical properties of rock salt and damage characteristics of the entire test analysis of energy transfer and conversion to explore the confining pressure and input energy on the specimen energy absorption and damage. The results show that under the same confining pressure, the hardening effect of rock salt is more obvious with the increase of incident energy, which shows that the energy reflectivity increases and the transmission energy and absorption energy decrease. Under the same or similar incident energy, The fluid plasticity of salt rock becomes more obvious when the pressure is increased, but the salt rock changes from fluid plasticity to brittleness under the dynamic load, finally the brittle failure occurs. With the increase of absorption energy, the peak stress of salt rock is different due to confining pressure Showing the different trend of change, the lower the confining pressure, the greater the absorption energy, the higher the peak stress, and the higher the confining pressure, the greater the absorption energy, the smaller the peak stress; in the confining pressure state, the salt rock impact The failure mode is similar to other brittle rocks, but there are big differences in the failure mechanism.