关键词: 深厚表土, 地面瓦斯抽排, 钻套管设计, 井壁结构

Abstract: In order to study the design of the ground gas drainage borehole casing in the deep alluvium region ,this paper from the establishment of the model, the work load of the selected casing, the choose of casing stability calculation formula and other aspects to study. The results showed that: from the permanent use considerations, Casing force model is similar to the drilling shaft ,so it can refer to the drilling shaft design, consider its use phase loads suffered; according to the thin-walled cylinder theory, pointing out that gas drainage borehole casing using high-strength steel is unreasonable from the perspective of force analysis; from the aspect of force and construction considerations, the safety factor of the ground gas drainage borehole wall-casing and work-casing in the deep alluvium region should be different considerations.

Key words: deep alluvium, gas drainage, casing design