谈破石头沟膨胀性围岩段引水隧洞施工

阐述了膨胀性土及膨胀性泥岩的基本特性及支护要求,并结合重钢西昌矿业有限公司破石头改道工程大型引水隧洞施工中膨胀性泥岩隧洞段的开挖支护经验,提出针对该类围岩隧洞的施工应坚持"短进尺、弱爆破、强支护、早封闭、勤量测"的施工理念,尽可能缩短开挖围岩的暴露时间,从而有效减少此类围岩的失稳垮塌。实践经验表明,文中介绍的施工工艺对于大断面膨胀性泥岩隧洞施工而言是合理可行的。

Water Tunnel Construction in the Poshitou-diversion of Expansive Mudstone

This paper describes the basic properties and the supporting requirements of the expansive soil and expansive mudstone.Combined with the excavation and support experience of the project in Poshitou-diversion in Chongqing Xichang Mining Co. Ltd. with expansive mudstone tunnel construction oflarge-scale water tunnel, concept of ＇ short footage, weak blasting, strong support, early closing, frequent measure ＇ had be put forward for this kind of surrounding rock oftuunel construction. In the meantime, shorten the exposure time of excavation as much as possible to effectively reduce the collapse of such unstable surrounding rock. Practical experience shows that the construction technology describing in this paper is reasonable and feasible for such large section of expansive mudstone tunnel.