变桩长与变桩距技术在处理桥头软基中的应用

Application of Changing Piles Length and Space Technique Treating Soft Foundation at Bridge Head

在软土地基上修建高等级公路时,“桥头跳车问题”是一个技术难题,利用变桩长与变桩距的预制管桩复合地基技术,在桥头软基上设置过渡段,可使堆载排水固结法处理的一般路段与桥头之间的工后沉降平稳过渡,缓解了此两种工法处理路段的沉降差异,并能减小桥头段的纵坡率,利用该技术在杭州湾跨海大桥南岸接线段高速公路试验段的桥头软基处理中效果理想。

In the highway construction on soft foundation, ＂bumping at bridge head＂ is a difficult technical problem. A transitional section between using pipes and preloading method is arranged along embankment of the bridge head. Through changing prestressed pipe piles length and space, it can reduce the settlement difference and remove settlement. It is more significant that the road surface is basically smooth because of the piles with different length and space along the embankment. The result shows that this composite foundation technique is useful and successful for the experimental section of south shore expressway connected Hangzhou Bay Spanning Bridge.