沙沱水电站5#坝段抗滑体稳定处理 开挖控制爆破施工技术

沙沱水电站5#坝段坝基存在缓倾角裂隙和软弱夹层及断层构成底滑面的深层抗滑问题，经研究比选方案，确定采用坝下混凝土抗滑体处理方案。本文将重点介绍抗滑体扩挖时为减少对已浇筑混凝土和周边岩石的影响所采用的分区分台阶开挖及施工预裂、减振孔等多项隔振措施进行的控制爆破。其爆破方式、装药量及孔位布置根据现场爆破试验确定，同时不断优化了爆破方案，合理确定了爆破毫秒延时间隔时间，做好了施工过程中的爆破震动监测，安全防护措施，确保了工程施工安全，可供类似工程参考。

Controlled blasting excavation technology for stability treatment with anti-slide body for No.5 dam block of Shatuo Hydropower Station

The deep sliding problems of low dip-angle fissures，weak intercalated layers and fault formed bottom sliding surfaces are there in the foundation of the No.5 dam block of Shatuo Hydropower Station; for which a scheme of the treatment with under-dam concrete anti-slide body is determined through the selection on several alternatives. The controlled blasting with many vibration isolation measures such as zoning and stepping excavation，construction pre-splitting blasting，damping holes，etc. for lowering the impacts on both the previously placed concrete and the surrounding rock during the expanding excavation for the anti-slide body is mainly described herein. The type of blasting，blasting dosage and arrangement of blasting holes are determined in accordance with the in-situ blasting test concerned，simultaneously，the blasting scheme is continuously optimized with reasonable determination of the interval of the millisecond delay for blasting and the perfection of the measures of blasting vibration monitoring and safety protection during the construction. Therefore，the construction safety is ensured and a reference can be provided for the similar project as well.