对为维护下部已采空的上覆岩层稳定状态所留下的各类矿柱的矿量进行二次开采时，地质力学状态变化很大，地质力学的主要过程包括岩层移动（平稳移动、上覆岩层的崩落）和从待采矿柱向残留矿柱的负荷再分布。本文论述了预测地质力学过程形态和参数的方法，讨论了利用二次开采模型研究上覆岩层自然崩落的各种情况。 When secondary mining is carried out to maintain the ore mass of various pillars left over by the steady state of the overlying strata in the lower part of the lower part, the geomechanical conditions change greatly. The main processes of the geomechanics include the movement of the strata (smooth movement, upward Overburden caving) and redistribution of load from the mining pillar to the residual pillar. This paper discusses the methods of predicting the formation and parameters of the geomechanical process, and discusses various situations of using the secondary mining model to study the natural caving of overlying strata.