Effect of coal thicknesses on energy evolution characteristics of roof rock-coal-floor rock sandwich composite structure and its damage constitutive model

The stability of the sandwich composite structures formed by leaving coal pillar, roof rock and floor rock (RCF) is of great significance to safe production of coal mines. The failure of coal and rock is actually a state instability phenomenon driven by energy. In order to explore energy characteristics of RCF sandwich composite structures, uniaxial compression tests with different coal thicknesses were performed by numerical simulation tests....