The initial section of tunnel had to be dug by hand.

隧道的起始部份不得不人工挖掘。

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This paper introduces excavation of the unfavorable geological section of tunnel project of Wanjiazhai YRDP, temporary brace and construction of concrete lining.

文中介绍了万家寨引黄隧洞工程不良地质洞段施工中的开挖，临时支护，混凝土衬砌等。

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Miners watch as the drill machine 'Sissi' breaks through the rock on the final section of the Gotthard Tunnel.

打通山体的工人正在查看钻孔机器“茜茜公主”打穿圣哥达隧道最后一部分的岩石。

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Patrick Morris, of the Friends of Cromford Canal, said only a small section of the tunnel was accessible.

BBC: Butterley tunnel gets Scheduled Ancient Monument status

During the week-long exhibition at the Scottish Parliament to celebrate the Scottish contribution to the creation and operation of the Large Hadron Collider visitors are able to walk through a full-size replica of a section of the LHC tunnel.

BBC: Scotland