龙首二级水电站工程施工关键技术

Key construction techniques for Longshou Hydropower Station II

甘肃龙首二级水电站大坝坝型为异型混凝土面板堆石坝,最大坝高 146 5m.为保证工程进度,施工中将原常态混凝土改高趾墙用碾压混凝土施工,并在坝料开采中采用了洞室爆破技术.而且用挤压式混凝土边墙替代了面板坝上游坡面常规施工法.实践表明,垫层料和挤压边墙之间未发生脱空现象,并对混凝土面板的约束很小,无需涂刷乳化沥青等隔离剂;同时在趾板、泄洪洞放水塔钢筋施工中采用了钢筋等强直螺纹连接技术.所有这些均获得了良好的施工效果.

The dam of Longshou Hydropower Station II in Gansu Province is a special-typed concrete face rock fill dam with maximum dam height of 146.5m. During the construction the normal concrete for the high toe wall originally designed is changed into a RCC one and the camber blasting is used to the filling material quarrying as to guarantee the construction progress concerned. Furthermore, the conventional construction for the upstream concrete face is replaced by a method of pressing concrete side wall,of which the result shows that no any cavities exist between the fill and the pressing wall,while only little restriction on the concrete facing slab and no need to used the insulating materials such as emulsified asphalt etc. Additionally, the reinforcement connection technique of straight iso-strength screw thread is used in the construction of the reinforcement of both the toe slab and the outlet tower of the discharge tunnel. On the whole,good construction efficiencies are obtained with all of the key techniques presented herein.