Influence Research for Softening and Swelling of Weakly Cemented Soft Rock on the Stability of Surrounding Rock in Roadway

Table 1

Mechanical parameters of surrounding rock of roadway.

Rock types	Density (kg/m^3)	Elasticity modulus/GPa	Poisson’s ratio	Prepeak cohesion/MPa	Prepeak internal friction angle/°	Residual cohesion/MPa	Residual internal friction angle/°	Tensile strength/MPa	Dilatancy angle/°
Sandy mudstone	2280	4.1 (3.3)	0.28	1.64 (1.39)	31 (30)	1.0 (0.4)	28 (25)	1.2 (1.0)	6 (45)
Mudstone	2150	3.7 (3.0)	0.30	2.05 (1.74)	30(29)	1.2 (0.5)	26(24)	1.6 (1.4)	5 (55)
Fine sandstone	2600	6.5	0.23	1.96	35	0.6	32	1.6	12
Medium sandstone	2510	5.9	0.25	1.78	34	0.5	31	1.5	10
Siltstone	2480	5.0	0.24	1.82	34	0.6	31	1.4	11
Coal mine	1450	2.4	0.28	1.42	31	0.6	30	1.0	7

Note. The number in the bracket is the corresponding parameter value of soft rock after water absorption.