三峡库区泥质粉砂岩的 SHPB 试验及能量耗散特征研究

摘要

为了研究含水状态下泥质粉砂岩的动态力学性能，进行了不同冲击速度下的分离式霍普金森压杆动载试验，重点研究泥质粉砂岩动力冲击过程中的能量耗散特征。结果表明：加载速率及含水率的变化将对岩样破坏均产生较大的影响。含水率的变化对岩样能量耗散特征产生较大影响，冲击速率越高时，试件的应变率越高，含水率越大时，比能量值及破碎程度也越高，平均破碎块度 d－越小；含水率的变化是导致断裂韧度变化的重要影响因素，含水率增加将导致试件的断裂韧度降低，在相同的冲击荷载下更容易断裂成碎块。%This paper aims to comprehend the dynamic mechanics performance of argillaceous siltstone in the moisture conditions.It carries out the split Hopkinson pressure bar test on argillaceous siltstone under different impact speeds.The energy dissipation characteristics of the samples are carefully analyzed.The results show that the loading rate and moisture condition play a great role on the failure of rock samples.The change of moisture content has a great influence on energy dissipation characteristics of the rock sample under the same impact load.The higher the impact rate,the higher the strain rate of the specimens.The greater moisture content,the specific energy absorption and the degree of fragmentation also become higher,the average lumpiness of fragmentation becomes smaller.Change of water content is the main factor that leads to the change of fracture toughness.Increase of moisture content leads to the reduction of the fracture toughness of the specimen,which will result in breaking into smaller pieces more easily.