高速铁路深厚地层CFG桩复合地基变形计算经验系数分析

摘要

In order to discuss the variation characteristics of deformation calculation empirical coefficient of fric-tion-type CFG pile composite foundation under the embankment load,based on the survey and design informa-tion and settlement field test data of six embankment sections of two test sections of Beij ing-Tianj in Intercity Railway and Beijing-Shanghai high-speed rail,an analysis was performed on the relationship between the de-formation calculation empirical coefficient of the deep soft soil layer and equivalent compression modulus,and the influences of the thickness of the compressed layer on the relationship.Such conclusions are made as fol-lows:under the embankment load,the deformation calculation empirical coefficient of the CFG pile composite foundation of the deep soft soil layer is decreased with the increase of the equivalent compression modulus, which presents remarkable negative correlation with the thickness of the compressed layer and is significantly larger than the recommended value stipulated in the technical code of railway engineering.The difference could more than double.The corresponding suggestive values of deformation calculation empirical coefficient are pro-posed,with regard to the corresponding thickness of foundation compressed layer with the respective stress ra-tio of 0.1 and 0.15,which has certain significance to the improvement of the foundation deformation calcula-tion in railway engineering.%为探讨路堤荷载作用下摩擦型CFG桩复合地基变形计算经验系数变化特性，基于京津城际和京沪高铁2个试验段共6个路堤断面的勘察设计资料和沉降观测数据，分析深厚松软土地基变形计算经验系数与当量压缩模量的关系及其受压缩层厚度的影响规律。结果表明，高速铁路区间路堤荷载条件下，深厚松软土 CFG桩复合地基变形计算经验系数随当量压缩模量的增加呈递减趋势，与压缩层厚度之间表现出显著的负相关性特征，并明显大于铁路技术规程的推荐值，差异可达1倍以上。针对应力比为0.1和0.15所对应的地基压缩层厚度，分别提出相应的地基变形计算经验系数建议值，对完善铁路工程的地基变形计算技术有一定意义。