深厚软土地基上跨浅埋地铁桩板结构施工技术研究

桩板结构具有强度高、刚度大、稳定性好、沉降小等特点。沪杭客运专线DK5+344.8～DK5+374.8段为上跨浅埋地铁深厚软土路基,采用桩板结构处理此段特殊路基。对施工难点进行分析,深入研究桩板结构路基的施工技术,包括施工控制要点、施工工艺和施工流程等。采用全套管钻孔桩施工工艺,对桩板结构钻孔桩桩底进行注浆加固,基坑开挖与混凝土浇筑施工按分部、分段进行,同时采用硬化施工场地等措施。工程实践表明,桩板结构新技术、新工艺的应用,满足了深厚软土地基沉降控制要求。

Research on Construction Technology of Sheet-Pile Structure Used for Deep Soft Soil Subgrade Crossing above Shallowly-Buried Metro

Sheet-Pile structure has characteristics of high strength and stiffness,good stability and small settlement.DK5+344.8~DK5+374.8 section of Shanghai-Hangzhou Passenger Dedicated Railway had deep soft soil subgrade crossing above a shallowly-buried metro,so sheet-pile structure was adopted to treat this spacial subgrade.This paper analyzed the construction difficulties firstly and deeply studied the construction technology of sheet-pile structure used in this special subgrade.This construction technology consisted of construction controlling points,construction process and procedure and so on.Full-sleeve bored pile technology was used and the bottom of the pile was strengthened by grouting method.Foundation pit excavation and concrete pouring were processed by sections and step by step.At the same time,construction site hardening measures were implemented.It has been found that this construction technology of sheet-pile structure has been able to meet the requirments on settlement control of deep soft soil subgrade.