土岩组合地层双排桩深基坑支护技术

通过总结某核电厂取水闸门井深基坑支护工程,论述了土岩组合地层基坑支护方案选型,介绍了双排桩支护设计及计算要点、基坑降水排水要点、监测项目布置以及基坑实际使用效果等。得出:土岩组合地质条件的基坑应进行分层支护,在上、下基坑间应预留一定的岩土体平台,在上部为砂层及珊瑚礁(块)混砂、下部为强(中)风化岩的基坑中采用无支撑双排桩结合止水帷幕的方案是可行的。

Double-row piles support technology for deep foundation excavation in rock-soil combinational ground

By reviewing the deep foundation excavation case for a gate shaft connecting with the water intake tunnel of a nuclear power plant, this paper describes the scheme choosing of foundation excavation supports in rocksoil combinational condition, and also introduces key points of design and calculation for double-row piles supports, key points for dewatering and drainage of foundation excavation, monitoring item, and final actual performance of the foundation excavation. The result shows that the foundation excavation in topsoil and subrock can be supported in two layers, a platform should be arranged between the topsoil and subrock, double-row piles with no strut combined with cutoff is suitable for the rock-soil combinational ground with topsoil of sand and coral reef fragment, underlayer of moderate or highly weathered rock .