Study on Numerical Simulation Test of Mining Surface Subsidence Law under Ultrathick Loose Layer

Table 1

Parameters of strata.

Rock strata	Thickness/m	Density/kg·m^-3	Uniaxial compressive strength/MPa	Tensile strength/MPa	Elasticity modulus/GPa	Cohesion/MPa	Internal friction angle/°
Loose layer	724.7	2210
Fine sandstone	1.6	2340	76.8	6.9	19.6	19.28	36
Mudstone	75.09	2470	40.8	5.7	6.56	11.36	30
Fine sandstone	3.87	2340	76.8	6.9	19.6	19.28	36
Mudstone	5.98	2470	40.8	5.7	6.56	11.36	30
Fine sandstone	15.15	2340	76.8	6.9	19.6	19.28	36
Mudstone	8.15	2470	40.8	5.7	6.56	11.36	30
Fine sandstone	16.18	2340	76.8	6.9	19.6	19.28	36
Coal 3	4.04	1350	15.8	1.8	3.52	4.82	28
Mudstone	4.01	2470	40.8	5.7	6.56	11.36	30
Fine sandstone	10.7	2340	76.8	6.9	19.6	19.28	36