Investigations of Coal-Rock Parting-Coal Structure (CRCS) Slip and Instability by Excavation

Table 1

Physical and mechanical properties of the rock parting, roof, and floor.

Material	Lithology	Thickness (m)	UCS (MPa)
Rock parting	Mudstone	0.7–1.6 (average = 1.1)	30–35
Immediate roof	Medium sandstone and mudstone	0–3.48 (average = 2.93)	35–40.5
Primary roof	Fine sandstone	7.7–12.9 (average = 9.61)	70.7–85.4
Immediate floor	Mudstone and siltstone	0–11.76 (average = 10.85)	28.6–44.2
Primary floor	Siltstone	10.3–11.9 (average = 11.03)	60.1–71.6