Study on Rock Burst Event Disaster and Prevention Mechanisms of Hard Roof

Table 1

Summary of parameters.

Object under study	Number of programme groups
	Programme I	Programme II	Programme III
Roof thickness (m)	10, 20, …, 100 (interval 10)	41.6	41.6
Tensile strength of roof (MPa)	13.5	4.5, 6, …, 18 (interval 1.5)	13.5
Tensile strength of coal mass (MPa)	15.99	15.99	1.25, 3.25, …, 19.25 (interval 2)
Number of groups	10	10	10