软弱土中大面积深基坑工程快速支护施工技术

Rapid Construction Method of Large Area Deep Foundation Excavation in Soft Soil

对于天津软弱土地基中大面积基坑,应用与发展了多种无大面积水平支撑的基坑快速支护施工方法,包括单排桩(墙)+反压土支护、双排桩+反压土支护、双排桩+单排桩联合支护、重力式挡土墙+反压土联合支护等方法。可靠的变形预测手段、止水帷幕、良好的反压土区降水效果、利用时空效应分块开挖基坑并分块施工地下结构是本方法控制变形关键。与传统方法相比,这些方法可显著缩短大面积基坑中高层建筑的施工工期,显著减小基坑支护造价并减少支撑拆除形成的固体废弃物等。

The rapid construction methods of large area deep foundation excavation in soft soil are applied and developed in Tianjin.These methods include combined retaining pile（wall） and earth berm,combined double-row retaining pile and earth berm,combined double-row retaining pile and single row retaining pile,combined gravity retaining and single row retaining pile.The key respects of these methods include accurate deformation prediction,waterproof curtain,dewatering of earth berm,time-space effect of staged excavation and underground structure construction.Compared with the conventional retaining methods,the rapid retaining methods of large area deep foundation excavation have the advantages of short construction period of underground structure of high-rise building,low cost and less discharge of solid waste produced by the demolish of concrete struts.