特殊地质条件下深覆盖层固结灌浆快速施工技术

Fast construction technique of consolidation grouting applied in deep overburden under special geological conditions

为满足工程防汛的要求，在麒麟寺水电站导流明渠（泄洪闸工程）施工中，采取了特殊工程处理措施。经过工艺改进，在25d内完成了21．0m高混凝土挡墙的混凝土浇筑和13．6m深复杂覆盖层的固结灌浆。采用孔口封闭、水泥浆循环、自上而下分段循环钻灌施工，回填砂卵石层和塌孔严重孔段水泥浆固壁、钻杆跟进灌浆的改进措施，使用早强水泥缩短Ⅱ序孔待凝时间，Ⅱ序孔与Ⅱ序孔进行交叉作业，相对高差控制在5—6m，从而加快了施工进度。上述地层经过灌前灌后对比检查和注水实验分析，均达到理想的效果，满足设计地基承载力和基础防渗要求，取得了一系列经验参数，该工程运行工况良好。

In order to satisfy the requirement of flood prevention, special treatment measures are adopted in the construction of open diversion channel （flood gate works） for Qilinsi hydropower project. By process improvement, concrete pouring and consolidation grouting had been conducted for 21m - high concrete guard wall and 13.6m - deep complicated overburden within 25 days, which is seldom seen in hydropower construction. The descending stage grouting method with collar seal and cement mortar circulation is selected to backfill sand -pebble layer and consolidate slurry wall in severely collapsed holes. With the improvement of grouting following drill rods, the use of early strength cement has shortened waiting on cement in the secondary holes, and is able to perform crossing activity between the primary and secondary holes. The relative height difference is controlled within 5 - 6m so as to speed up the construction progress. By comparison to water injection check and analysis before ＆ after grouting in the above stratum, a good effect has been achieved, meeting the bearing capacity and anti - seepage requirements of the foundation. A series of empirical parameters have been obtained, with good operation of the project.