Applying long horizontal roof rock hole to drain the gas from adjacent seam and goaf is a new technique. In this paper, introduces the latest progress of this technique is introduced fully.

采用顶板岩层水平长钻孔抽放邻近层和采空区瓦斯是一项新技术，全面介绍了该技术研究的最新进展。

youdao

The "no dig" technique involves inserting a liner impregnated with a special resin into a sewer or drain.

BBC: Sewer renovation work to begin in Glastonbury