Stress Analysis of Negative Coal Pillar Gob-Side Entry and Its Principle of Preventing Rock Burst

Table 1

Thickness and physical or mechanical properties of rock strata.

Rock strata	Thickness (m)	Density (kg·m^−3)	Compressive strength (MPa)
Medium sandstone	50	2500	27.2
Mudstone	8	2500	9.4
Siltstone	13	2600	27.0
Limestone	6	2500	31.4
Shale	7	2550	9.40
Sandy mudstone	6	2500	20.6
Siltstone	10	2600	31.4
Mudstone	5	2500	9.70
Coal	6	1400	4.49
Mudstone	3	2500	9.70