竖曲线设计公式的推导及讨论

首先推导了考虑行车视距的公路竖曲线设计公式,发现中国路线设计规范中的竖曲线长度建议值不能满足行车视距要求的问题,尤其是没有照明的凸曲线路段夜间行车情形。建议我国的竖曲线设计应当考虑车辆前照灯所约束的夜间视距,提高竖曲线长度建议值。

Derivation and Discussion of Vertical Curve Design Formulas

The highway vertical curve design formulas for both crest and sag vertical curves with the consideration of stopping sight distance are first analytically derived.Driver height,object height,and vehicle headlamp height are explicitly considered as the key elements for stopping sight distance determination.Based on these formulas,the minimum vertical curve length values,as recommended in the China Road Alignment Design Guide are then shown to be inadequate,especially for crest vertical curve during nighttime...