武广高铁武汉综合试验段软土复合地基沉降分析  

Research on the Settlement of Soft Soil Composite Foundation for Wuhan Experimental Section of Wuhan-Guangzhou High-speed Railway

作　　者：张峰[1] 刘莹[1] 许兆义[1] 李志义[1] 

机构地区：[1]北京交通大学,北京100044

出　　处：《铁道工程学报》2015年第9期30-34,共5页Journal of Railway Engineering Society

基　　金：中央高校基本科研业务费专项资金资助(2012JBM085)

摘　　要：研究目的:不良地质环境条件下路基工后沉降的控制是高速铁路设计中的关键问题,过大的路基工后沉降会对高速铁路的运营产生不良影响。本文以武广高速铁路武汉综合试验段为例,运用有限元法对软土段采用CFG桩复合地基处理后的沉降特征进行研究。研究结论:(1)随着路堤填筑高度的逐渐增加,路堤高度越大其沉降量越大,复合地基CFG桩端沉降量随距路堤中心距离增加而减小,且在路堤顶面宽度以外快速衰减;(2)CFG桩与填土应力比随路堤填筑高度的增加而减小,桩土所承担的荷载分布更加均匀,桩土应力比随距路堤中心的距离增大而增大,路堤中心处桩土受力更均匀;(3)孔隙水压力随填筑高度增加而迅速增长,加载完成后便开始逐渐消散,路堤填土一年后,路堤中心处的孔压基本扩散均匀,约为38 kPa;(4)该研究成果可为高速铁路软土复合地基沉降控制提供参考。Research purposes： Control of post construction settlement under poor geological condition is the key issue in high -speed railway design. The greater post construction settlement will have bad effects on the operation of high - speed railway. Using finite element method （FEM） , this paper studies on the CFG pile composite foundation treatment of the soft soil subgrade settlement properties of the high - speed, as an example of Wuhan comprehensive test section of Wuhan - Guangzhou high - speed railway. Research conclusions： The result shows that： （1）The settlement amount gradually increases with the enhancing of height of the embankment. The settlement amount of composite foundation of CFG pile end decreases with the increasing of distance from the center of embankment, and rapidly decays in the outside of the top width of the subgrade. （2） The stress ratio between CFG pile and soil decreases with the increasing of the height of embankment, the load is becoming more uniform of CFG pile and soil. The stress ratio of CFG pile and soil increases with the distance from the center of embankment, embankment center~ force of piles and soil are more uniform. （3） Subgrade pore water pressure increases rapidly accompanied with the increase of embankment height, and begins to dissipate after completion of loading process. A year after the subgrade construction, embankment center pore water pressure almost spreads evenly, and its number is about 38 kPa. （4） The research result can provide a reference for the settlement control of soft soil composite foundation of high - speed railway.

关 键 词：高速铁路 软土路基 CFG桩 沉降量 

分 类 号：U213.152[交通运输工程—道路与铁道工程]