Failure characteristics of surface vertical wells for relieved coal gas and their influencing factors in Huainan mining area

从通过洞基于数据并且记载，我们在 Huainan 采矿区域和它的影响因素为减轻的煤气体学习了表面排水井的失败特征。结果证明排水井的损坏位置主要在西方采矿区域在基岩的上面的节在厚泥土层位于低冲积层和 lithological 接口。casing 的失败深度是 244 鈥 ? 70 m 并且在大约 270 鈥 ? 专注 60 m 深。这些损坏位置主要在划分的房顶上面在垂直的节根据岩石层的三个地区位于弯曲地区。通常， casing 以前开始使脸线变形或损坏大约 30 鈥 ? 50 m。特殊形成结构和岩石团性质是 casing 失败，高采矿高度和快进展速度的直接原因是为岩石质量的基本原因损坏。然而，到 casing 失败的地上凿穿配置和间距不是很清楚的。

Based on data from through-hole and logging,we studied the failure characteristics of surface drainage wells for relieved coal gas in Huainan mining area and its influencing factors.The results show that the damaged positions of drainage wells are mainly located at the thick clay layer in the low alluvium and the lithological interface in the upper section of bedrock in west mining area.The failure depth of casing is 244-670 m and concentrates at about 270-460 m deep.These damaged positions are mainly located in the bending zone according to three zones of rock layers in the vertical section above the roof divided. Generally,the casing begins to deform or damage before the face line about 30-150 m.Special formation structure and rock mass properties are the direct causes of the casing failure,high mining height and fast advancing speed are fundamental reasons for rock mass damage.However,the borehole configuration and spacing to the casing failure are not very clear.