underground working

This article is meant to point out the working procession and the structure of the pounding head, mainly analysis the extruding principle of pounding head in pneumatic impact puncher, when it is working underground.

据此介绍了冲击头的工作过程、结构，重点分析了气动穿孔机冲击头工作时在土壤中的挤压效应机理。

Application of Chamber Blasting for Opencast Working Instead of Underground Working in Coal Mine with Fire ( Down)

硐室爆破在火区煤矿井采转露采中的应用（下）

A whitened function on different grey kinds of underground working environment is given out.

根据煤矿生产实际,应用灰色系统理论建立了井下劳动环境聚类指标体系.

Working face is the floating working room underground.

采煤工作面是地下移动着的工作空间.

...opposition leaders, who are working underground because of the threat of arrest.

面临被捕危险不得不秘密开展工作的反对派领导人

The State shall take special protective measures for miners working in underground coal mines.

　　国家对煤矿井下作业的职工采取特殊保护措施.

The results have offered security guarantee condition when opencast working switches to underground working in the mine.

探测结果，为该矿由露天开采转入地下生产，提供了安全保障条件。