基于桥头跳车动力作用影响的台背回填处治技术研究

在考虑车辆动力模型及路桥过渡段不平整几何模型的基础上,采用3轴9自由度车辆运动动力模型,结合弹塑性动力有限元方法,建立可用于分析路桥过渡段车辆振动荷载作用的路基路面动力响应三维有限元模型,计算结果表明,由于路桥高差的激振,车辆将产生一定幅度的垂向和俯仰运动,路面受到的最大动力荷载作用在距离桥头10～30 m范围内;考虑到通平高速公路1-5合同段主要分布为全风化花岗岩,试验结果表明,当地全风化花岗岩填料0.075 mm通过率越小,渗透性越好,可采用强度相对高、颗粒粗的全风化花岗岩填料进行台背回填,其他标段则采用符合规范要求的碎石土填筑。

Research for Treatment Technology of Abutment Backfilling in Tong-Ping Expressway

Considered the vehicle dynamics model and the uneven geometric model of in bridge-subgrade transition,a 3-axis 9 freedom-degree dynamic model of vehicle movement is established n this paper.And combined with elastic-plastic dynamic finite element method,a 3-dimensional finite element model of dynamic response is built for subgrade and road surface,which can be adopted to analyze the vehicle vibration loading in bridge-subgrade transition.Calculation results show that due to the？excitation of bridge-subgrade height difference,vehicles will produce vertical and pitching movement in a certain range.And the maximum dynamic load on road surface operates in the range of 10~30 m from bridgehead.Taking into account distribution of completely weathered granite mainly in the 1-5 contract sections of Tong-Ping highway,test results show that the smaller the passing rate with 0.075mm for completely weathered granite filling,and the better the？permeability.Therefore,it is recommended that completely weathered granite filler which is relatively high strength and coarse particle,is adopted to backfill abutment,and？gravel soil meet the demands of specifications are adopted to fill in other contract sections.