Dynamic mechanical properties and energy dissipation of frozen weakly cemented red sandstone under high strain rate loading

To study the influence of a sub-zero temperature environment on the dynamic characteristics of weakly cemented red sandstone rock, a series of dynamic tests are conducted using a modified split Hopkinson pressure bar (SHPB) experiment system. The results show that the dynamic stress–strain curve of weakly cemented sandstone has plastic characteristics under lower sub-zero temperatures. The dynamic compressive strength (DCS) and elastic modulus of the rock have a typical strain rate sensitivity, which increases exponentially with the increase in the strain rate. When the temperature is decreased from normal temperature to sub-zero temperature, the DCS and elastic modulus increase. With the continuous decrease of temperature, both of the parameters show the characteristics of rapid increase and subsequent rapid decrease. The significant effect of sub-zero temperature on the energy dissipation of weakly cemented red sandstone is observed, wherein the energy dissipated per unit volume of rock, η , increases first and then decreases with the continuous decrease in the temperature. Finally, based on the experimental results, the influence mechanism of sub-zero temperature on weakly cemented rock is analyzed. The research results can serve as a guide for engineering construction in cold regions.