Mechanical Parameters of Deep-Buried Coal Goaf Rock Mass Based on Optimized GSI Quantitative Analysis

Table 10

Goaf roof mechanical parameters from field test.

Roof strata	Compressive strength (MPa)	Deformation modulus (GPa)	Friction angle (°)
9 coal roof sandstone and shale	3.53	1.52	40.5
11 coal top roof shale	3.91	2.85	39.7
11 coal lower roof sandstone	11.10	4.65	48.8
13 coal top roof shale	7.25	12.58	41.0
13 coal middle roof sandstone	14.82	19.02	51.8
13 coal lower roof limestone	12.97	12.43	47.1
15 coal roof shale	5.13	5.52	35.6