Study on stress manifestation and overlying strata movement laws under different lithological combinations

To gain insights into the impact of lithological and geometric configurations of Shendong strata on the propagation of damage within overlying rock layers, a model simulating overlying rock movement and damage propagation under varied lithological combinations was developed. The study involved four physical and seventeen numerical simulations to assess geological factors influencing strata be?havior post-mining. Key findings include: Decreasing the thickness of the key stra?tum reduces the first weighting interval, accelerates fracture initiation, enlarges the subsidence area, and increases maximum subsidence; Raising the key stratum elevation diminishes both subsidence and its range, while delaying fracture initi?ation; Reducing mining thickness results in smaller pressure fluctuations, slightly extends the first weighting interval, and decreases both subsidence and its range; Enhancing key stratum hardness delays fracture occurrence, lowers the fracture zone height, and decreases the plastic zone volume.