The experimental study on soft rock (analogized with mortar) under dynamic uniaxial compression at the strain rates from 10-5 to 101 s-1 has been carried out. It is indicated that the compressive strength of the soft rock increases with the increasing strain rate; and the rising rates are higher than that of hard rock. The Young’s modulus and Poisson’s ratio of the soft rock increase with the increasing strain rate
but the rising rates are less than that of compressive strength. In addition
based on the SEM results
the mechanism of the strain rate effect of the soft rock is primarily analyzed.