高速铁路CFG桩筏复合地基沉降变形特性研究

摘要

选取京沪高速铁路CFG桩筏加固软土地基的典型断面，采用ABAQUS有限元程序建立了三维数值模型。考虑高速铁路路堤分级填筑施工过程和长期荷载作用，对CFG桩加固后路基填筑期和运营期的沉降进行计算模拟，分析CFG桩筏复合地基沉降变形发展规律。研究结果表明：计算结果与实测值相一致，数值模型可以较好地反映路基填筑过程和后期沉降过程。基于该方法预测了高速铁路运行10 a后的沉降，桩筏复合地基技术可以有效地控制京沪高速铁路（凤阳段）的工后沉降，可为类似工程提供参考依据。%The typical section of CFG piled raft composite foundation was selected in Beijing-Shanghai high-speed railway in soft soils.The three-dimensional numerical model was built using the finite element software ABAQUS.The settlement during and after construction of improved foundation was simulated and calculated by considering the construction of subgrade and long-term loading.The deformation development of this foundation was analyzed.It shows that the results of numerical calculation agree well with observation values,and the nu-merical model can simulate the settlement process during and after construction of the improved foundation.The settlement after ten years’operation of high-speed railway is predicted based on this numerical method.The CFG piled raft composite foundation using CFG piled raft (Fengyang section)can control the post-construction settlement effectively,which could afford reference value to similar programs.