Predicting Overburden-Induced Failure Height of Large Mining Face in Shallow Coal Seam Based on Half-Plane Theory

Table 2

Rock layer weak surface coefficient ratio.

Overlying strata	Sandstone	Mudstone	Shale
Decline coefficient of the weak face of the rock formation	0.62∼1.0	0.29∼0.62	0.29∼0.31