roundabout way

This paper introduces the technologies of going through the collapsible columns, roundabout ways and pilot tunnels of the 3309 fully mechanized sub-level working surface in Chengzhuang Coal Mine, analyzes on the main problems existing and the corresponding measures, and discusses their economic benefit and social benefit.

介绍了成庄矿3309综放工作面过陷落柱、绕道和导硐的技术,分析了存在的主要问题并提出了应对措施,论述了其经济效益和社会效益。