深厚软土地区有轨电车轨下基础设计探讨

Exploration on Design of Tram Track Foundation in Deep Soft Soil Area

依托松江现代有轨电车示范线工程实例,探讨深厚软土地区不均匀沉降的成因,从土层参数差异性入手,利用随机有限元研究软土路基不均匀沉降问题;并从沉降控制和管线影响两方面,对有轨电车轨下基础选型进行了探讨和研究。分析表明,复合地基方案对路基沉降控制有较好的效果,但对密集管线影响较大;桩板结构方案不仅沉降控制效果好,而且结构厚度小,能大大降低管线的迁改量。最后,提出了松江有轨电车轨下一体化基础方案,并对桩板结构基础的跨长和桩长提出了优化建议。

Taking the Songjiang Modern Tram Demonstration Line Project as an example,the paper explores the reasons of uneven settlement in deep soft soil.Based on the difference of soil parameters,the subgrade uneven settlement is studied by stochastic finite element method.The selection of track foundation types is studied from the two aspects of settlement control and influence on the pipeline.The analysis shows that the composite foundation is good at control of subgrade settlement while it has a larger negative impact on the intensive pipeline; the pile-plank structure is not only good at control of subgrade settlement but also can greatly reduce the dislocation of pipelines due to thinin thickness.The integral track foundation scheme is proposed for the Modern Tram Demonstration Line Project in Songjiang,and suggestions are given on the span of pile-plank structure foundation and pile length.