The Influence of Heading Rate on Roof Stability in Coal Entry Excavation

Table 1

Summary of large-scale in situ tests.

Investigators	Cross section (cm)	Height (cm)	Peak strength (MPa)	Residual strength (MPa)	Ratio	Average
Van Heerden [26]	140 × 140	43	22.78	8.66	0.38	0.25
Bieniawski and Van Heerden [27]	140 × 140	54	20.58	4.72	0.23
Cook et al. [28]	125 × 104	170	8.58	1.26	0.15