旧路改造工程中缓和竖曲线和使用长度研究

Research on Alleviating Vertical Curve and Service Length in Old Road Reconstruction Project

摘要:

为提升旧路改造工程纵断面线形质量，以及减少使用不必要的昂贵沥青下面层衬垫材料，对缓和竖曲线及其使用基础等开展了研究。首先，确定“人-车-路”动力学计算模型和缓和竖曲线评价标准，通过动力学计算分析确定以多次抛物线为缓和竖曲线研究方向，并采用待定系数法推导出8次抛物线缓和竖曲线方程族；其次，分类讨论不同工程条件下确定缓和竖曲线的方法，并经动力学计算确定7次抛物线为最小振动缓和竖曲线；第三，采用动力学计算分析确定各设计车速下不设缓和竖曲线的最小竖曲线半径；最后，在动力学计算基础上建立缓和竖曲线基本参数与车辆振动评价指标关系，并结合车辆振动感知标准，确定了缓和竖曲线最小长度。以上研究形成了缓和竖曲线设计使用基本条件和相关使用基础，可供旧路改造工程设计中选用。

Abstract:

In order to improve the quality of longitudinal section alignment in old road reconstruction projects and reduce the unnecessary and expensive asphalt underlying lining materials, the alleviating vertical curve and its service basis are studied. Firstly, the "human-vehicle-road" dynamic calculation model and the alleviating vertical curve evaluation criteria are determined. Through dynamic calculation and analysis, the multiple parabolas are determined as the research direction of alleviating vertical curve. And the method of undertermined coefficients are used to deduce a family of equations of 8-degree parabola alleviating vertical curves. Secondly, the methods for determining the alleviating vertical curves under different engineering conditions are classified and discussed. And through the dynamic calculation, the 7-degree parabola is determined as the minimum vibration alleviating vertical curve. Thirdly, the dynamic calculation analysis is used to determine the minimum radius of vertical curve without alleviating vertical curve at each design speed. Finally, based on dynamic calculations, the relationship between the basic parameters of the alleviating vertical curve and the evaluation indicators of vehicle vibration is established. Combined with the vehicle vibration perception standards, the minimum length of the alleviating vertical curve is determined. The above research forms the basic conditions and relevant service foundations for the design of alleviating vertical curve, which can be selected in the design of old road reconstruction projects.