2018_EJRNL_PP_YI_TAN_1.pdf
Terbatas Resti Andriani
» ITB
Terbatas Resti Andriani
» ITB
The exact determination of the height of fractured
zones in overlying sedimentary strata is important in
coal mining performed underneath water bodies and
for a safe production. To prevent the inrush of water
and sand during strip Wongawilli mining, we studied
the height of fractured zones in shallow coal seams
underlying a hard roof. Based on the geological setting
and mining conditions at the Zhaowu coal mine, the
height of the fractured zones in overlying strata was
measured using the loss of drilling fluid method and
by numerical simulation. The height of the fractured
zones and its development characteristics during strip
Wongawilli mining in shallow buried coal seam underlying a hard roof were obtained. The results demonstrate that the disturbance of the overlying strata
during strip Wongawilli mining is reduced and the
height of the fractured zones is smaller relative to that
occurring during critical mining. The height of fractured zones increases with mining width in a steppedfinger line, and it manifests stable in each stage, but
turns into the next stage by sudden increase. The
existing method of calculation and the traditional
empirical formula to obtain the height of the fractured
zones are not suitable for strip Wongawilli mining.
The calculation should be based on the size of mining.