SPLIT HOPKINSON PRESSURE BAR TEST AND ENERGY DISSIPATION CHARACTERISTICS OF ARGILLACEOUS SILTSTONE IN THREE GORGES RESERVOIR REGION

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.