Abstract:

A split Hopkinson pressure bar (SHPB) testing system was constructed to study the mechanical properties of sandstone at high temperature. The dynamic compression loading tests of sandstone with temperature rate varying from 25 ℃ to 1 000 ℃ were carried out to study the relationship among the dynamic mechanical properties, such as peak stress, failure strain, elastic modulus, and temperature. The experimental results show that the relationship of the mechanical properties of sandstone with the temperature changes sharply at 100 ℃ and 200 ℃.With the increase of temperature, the peak stress and the elastic modulus all gradually decrease, while the failure strain increases when the temperature is over 200 ℃. The mechanical properties deteriorate rapidly with the increase of temperature when the temperature is above 600 ℃. In the sight of microstructure characteristics of sandstone, the mechanical properties of sandstone at high temperature were analyzed. It is found that the micro mechanism that the destruction of high temperature to the sandstone changes sharply with the increase of temperature. The research conclusions can provide references for analyzing the dynamic mechanical behavior of the country rock of underground projects at high temperature.

Key words: explosion mechanics, dynamic rock mechanic, large-diameter split Hopkinson pressure bar, sandstone, high temperature