Theoretical Analysis and Numerical Simulation of the Graben Fault Instability Mechanism

Table 1

Mechanical parameters of rocks.

Rock	Density ()	Bulk modulus (GPa)	Shear modulus (GPa)	Internal frictional angle (°)	Cohesion (MPa)	Tensile strength (MPa)
Medium sandstone	2450	3.83	2.41	41	3.26	36
Fine sandstone	2600	3.45	2.00	40	3.80	1.80
Coal	1400	3.00	1.00	28	1.60	0.90
Mudstone	2300	4.45	1.60	39	3.30	1.75
Medium fine-grained sandstone	2900	2.66	0.84	35	2.85	1.10
Fault rock	1000	0.074	0.50	22	0	0