列车荷载下巴准重载铁路高路堤路基累积变形研究

针对巴准重载铁路高路堤典型断面,采用三维非线性有限元与经验公式相结合的方法,建立了可考虑列车-轨道动力相互作用的重载列车振动荷载引起的高路堤路基累积变形计算方法。首先,基于列车-轨道垂向耦合动力系统理论,建立重载列车-轨道动力耦合体系数值模型,并实施重载列车-轨道耦合系统动力分析;其次,建立轨枕-道床-路基-场地动力系统的三维有限元模型,并输入求解的列车振动荷载作为外部激励;最后,采用Li和Selig推荐的改进土体累积变形预测模型并结合有限元分析结果,分析了未加固和应用土工格栅加固的高路堤路基累积变形的基本特征与规律。发现土工格栅可显著减小路基的动力累积变形作用。

Slope Stability Analysis of High Embankment at Ba-quasi Heavy-load Railway

To the question of the typical section of the Ba-Quasi heavy-load railway high embankment,using the combination technology of 3Dnonlinear dynamic finite element method and empirical model and considering the dynamic coupling effect of heavy-load vehicle-sleeper-ballastsubgrade-field,the computing method of accumulated settlement of high embankment caused by the long time train vibration load was set up.Firstly,based on the vehicle-track vertical coupling dynamic system theory,the numerical model of heavy-load vehicle-track dynamic coupling system was determined,and the analysis of the system was carried out.Secondly,the finite element model was set up considering the dynamic interaction system of sleeper-ballast-subgrade-field,and the solution of the train vibration load was taken as external excitation of the model.And lastly,combining accumulation of soil deformation prediction model improved by Li and selig the results of the FEM,the basic rule of accumulation deformation was determined comparing the high embankment subgrade reinforced with geogrid and unreinforced,then the research shows that the geogrid plays a very important role in reducing the dynamic accumulated deformation of the subgrade.