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本文取自美国英格索尔—兰德公司的小册子《新发明的矿山与隧道支护形式》,共46个问题,本刊将分期刊登,供读者参考,以期对矿山支护工作有所裨益。
This article is taken from the booklet entitled “Newly-Developed Mines and Tunnel Support Forms” by Ingersoll Rand Company of the United States. There are 46 issues in this book, which will be published for readers’ reference in the hope of helping mine support work. benefit.