三门核电软土深基坑工程相关问题分析与探讨

Deep Excavations in a Soft Clay Site in Sanmen Nuclear Power Plant

针对三门核电排水箱涵软土深大基坑工程地质条件复杂、工程线长、涵宽多变等难题,设计采用桩锚、内支撑、重力挡墙三种支护型式,支护桩间搭接旋喷桩共同构成防渗帷幕,设置人工岛形成渣土运输系统。通过支护桩、防渗桩、基底工程桩及支护用短桩所构成的整体支护系统,满足了基坑安全和干作业要求。对设计优化和施工过程中的相关问题进行了分析探讨,分析成果可以为类似软土深基坑支护和地基处理提供参考。

The circulation water discharge culvert in Sanmen Nuclear Power Plant is within the thick soft soils. It is characterized as having a complicated geotechnical conditions, long total linear length and the variation of the box width. Three deep excavation alternates are used： anchored soldier pile and lagging wall, soldier pile plus rake and gravity wall. A slurry wall is formed by using the jet grout between the soldier piles. The transporting of the excavated soils is through the artificial island. The construction and the safety of the excavated area is warranted through an integral system consisting of supporting piles, slurry wall as well as foundation structure piles at the bottom. The paper also presents the results of the construction optimiza- tion of the installation sequence.