黄丹电站推行工程监理体制创优质工程

黄丹电站推行工程监理体制创优质工程四）１１省＂八五＂重点工程－－装机４－５万ｋｗ的黄丹电站，在工程施工中充分与国际贯例接轨，全面推行工程监理体制，强化对工程质量、工期和投资的控制，防止出现病害工程，确保工程优质、高效、低耗建成。黄丹电站地处四川省沐川...

Technical measures of underground opening construction for Geheyan Project

The Geheyan Hydropower Plant has four power tunnels. The net spacing between adjacent tunnels is approximately equal to the excavated diameter of the tunnels.Blasting action in post-excavated tunnels will produce unfavourable influence on the concrete lining in fore-excavated ones.To solve this problem, fore-excavating the heading,post-expanding,full-periphery shotcrete suppot were adopted. in addition,during the excavation process,a lot of construction monitoring were carried out.Through these measures good engineering quality and completion tunnel works ontime.have been achieved.The project's tunnels with large diameter pass through strong weathered limestone with weak shale strata. By meanS of short driving footage,weak blasting and shotcrete with steel arch truss support,formation of an exactly circular excavation cross section under unfavourable geological conditions has been achieved.