The paper presents the principl,supporting parameters and constructional technology of bolting stope roof beforehand by long cable anchor.

 
  • 闡述了采場(chǎng)頂板長(cháng)錨索預錨固技術(shù)的原理、支護參數及施工工藝。
今日熱詞
目錄 附錄 查詞歷史
国内精品美女A∨在线播放xuan