中文摘要：

为分析软土地区的高速铁路路基沉降规律，以某客运专线软土地基处理的工程实例为研究对象，对该段路基填筑过程和工后长期地基沉降观测结果进行分析，认为采用“水泥粉煤灰碎石桩＋土工格栅＋水泥级配碎石桩”复合地基加固形式的地基处理十分有效，满足客运专线地基沉降要求小于15mm的要求。根据该工程实例情况，利用有限元分析软件ADINA建立相应的路基计算模型，模拟了桩径和桩间距不同时，路基填筑过程中地基表面的沉降变形规律，基于数值模拟结果建立了路基填筑过程中地基沉降的预测公式。数值模拟结果与现场沉降观测结果具有相同的规律，随着路基填筑高度的增加，地基沉降变大，且呈凹形沉降。研究结果表明，桩径和桩间距与地基沉降关系较大，桩径与地基沉降量成负相关关系，桩间距与地基沉降量正相关。

英文摘要：

The problem of sub grade settlement of high-speed railway in the soft soil area has aroused extensive attention. The observation data of foundation settlements during embankment fill- ing process and long period observation foundation treatment of Beijing-Shanghai were analyzed by taking a section in the project of soft soil express railway as the research object. The analysis results show that the method of cement fly-ash grave pile and geogrid and cement gradation macadam could satisfy the requirement that sugrade settlement is less than 15 mm. The corresponding model of the foundation is established by using ADINA. The settlement deformations during embankment filling process are simulated for different pile diameters and spacing. The numerical simulation results and the settlement observation results have the same regularities. When the filling becomes higher, the foundation settlements will become larger and the settlement curves are concave. The formulas for subgrade foundation settlement in different process of filling are established based on the numerical simulation results which also show that pile diameters and spacing are related to foundation settle- ments. The foundation settlements become larger when the pile diameters decrease, and become smaller when the pile spacing increases.