京沪高铁桩基沉降时间曲线反分析及预测  

Back Analysis and Prediction of Settlement-Time Curve of the Pile Foundation of Beijing-Shanghai High-speed Railway

作　　者：邓东平[1] 李亮[1] 赵炼恒[1] 邹金锋[1] 

机构地区：[1]中南大学土木工程学院,长沙410075

出　　处：《长江科学院院报》2012年第4期57-63,共7页Journal of Changjiang River Scientific Research Institute

基　　金：西部交通建设科技项目(2006318802111);铁道部科技研究开发计划重点资助项目(2008G032-3);湖南省交通厅科技项目(2007-29);中南大学优秀博士学位论文扶植项目(2008yb004)

摘　　要：在京沪高铁项目中,针对深厚软土地层中的桩基工程,使用FLAC3D建立的桩基模型进行计算。同时,利用桩基静载试验所得的沉降-时间曲线,在考虑土体存在蠕变效应时,结合位移反分析方法,对桩基土体参数和蠕变参数进行反演。在得到反演参数后,对桩基在长期荷载作用下的沉降进行预测。研究表明:①数值反演结果与实测结果比较相符;②使用反演参数对桩基长期荷载作用下的沉降进行预测,得出未注浆桩和注浆桩在长期荷载作用下的前期沉降量大,且基本达到最大沉降量,后期没有出现明显的蠕变效应。因此,建议可不需要通过注浆来对桩基的蠕变效应进行改善,且当在工期较为紧张时,可减少桩基静置时间。The settlement of pile foundation in deep soft soil for Beijing-Shanghai high-speed railway is calculated by using a pile foundation model established in FLAC3D.When the creep effect of soil is considered,the soil parameters and creep parameters of pile foundation are inverted by using settlement-time curve obtained from pile settlement test under static load.Based on the inverted parameters,settlement of the pile foundation under long-term load is predicted.It＇s shown that the results of numerical back analysis are consistent with observed results.By predicting the pile foundation settlement with inverted parameters,it＇s found that the settlements of both ungrouted piles and grouted piles are large in the early stage,approaching to the maximum,yet with no obvious creep effect in the later stage.Therefore,it＇s suggested that there is no need to reduce the creep effect by grouting and when the construction schedule is more intense,the reposing time of pile foundation can be decreased.

关 键 词：桩基 FLAC3D 沉降 蠕变 反分析 预测 

分 类 号：U213.1[交通运输工程—道路与铁道工程]