The latest experimental results of rock creep were used : the third invariant of deviator stress tensor had greater effect on creep properties ; the stress threshold of lateral creep of rock was 20 % ~ 40 % less than that of axial creep of the same rock 文中应用了课题组近期岩石流变实验研究的结果:应力偏量第三不变量对岩石蠕变影响显著;岩石侧向蠕变的应力阀值比轴向蠕变应力阀值低20 % ~ 40 % 。