The results show that if there exists a key stratum in the omitted strata, it will lead to the distortion of the distribution of load and the simulation result of key strata fracture...

• 只有主关键层上部的岩层可以简化为均布载荷；包含关键层时不能简化为均布载荷；其等值载荷与被省略岩体中关键层的位置及其破断特征有关.