首页 > Term: four-piece set
four-piece set
Squared timber frame used in underground driving to give all around support to weak ground. A cap is supported by two posts on a sill-piece or sill.
- 词性: noun
- 行业/领域: 采矿
- 类别 一般矿业; Mineral mining
- Government Agency: USBM
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创建者
- ed.young
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(Milwaukee, United States)