Table 5 Roof and floor conditions of working face.
From: Analytical prediction of groundwater loss in deep coal mines induced by ground vibration
Rock name | H (m) | Thickness (m) | Lithological characteristics | |
|---|---|---|---|---|
Clay | Basic top | 92.30 | 5.66 | Thick layered structure composed of feldspar and quartz |
Sand | 98.53 | 6.23 | Off-white coarse particles, mainly quartz and feldspar | |
Mudstone | 99.99 | 1.46 | Dark grey, muddy structure, thin plate-like structure | |
Fine-grained sandstone | Direct top | 103.77 | 3.78 | Light grey, massive, mainly composed of quartz, semi-hard |
Coal | 113.00 | 7.5–9.1 | Locally developed fissures, the surface coal seam are mainly long-flame coal and semi-coking coal | |
Mudstone | Direct bottom | 114.04 | 1.04 | Grey massive, uniform in texture, brittle, flat fracture |
