ABSTRACT

The equations used to calculate horizontal curve radius are presented in geometric design regulations based on the following assumption: the curve is on the flat ground without overlap with longitudinal slope or any vertical curve. The aim of this study is to evaluate the effect of overlapping longitudinal slope and vertical curves on the horizontal curve radius. For this purpose, three different cases are investigated: horizontal curve in a flat road, horizontal curve in a sloping road, and horizontal curve in the presence of a vertical curve. For the above-mentioned cases, different forces are exerted on the vehicle. The direction of their effect is modeled using the point-mass method, and the equations for determining minimum horizontal curve radius are extracted. The results demonstrate that the equations for the overlap of a horizontal curve with a crest vertical curve indicate a need for increasing the horizontal curve radius in some cases.

摘要

在几何设计规范中，基于以下假设提出了用于计算水平曲线半径的方程式：曲线位于平坦的地面上，不与纵向坡度或任何垂直曲线重叠。这项研究的目的是评估重叠的纵向坡度和垂直曲线对水平曲线半径的影响。为此，研究了三种不同的情况：平坦道路上的水平曲线，倾斜道路上的水平曲线以及存在垂直曲线的水平曲线。对于上述情况，不同的力施加在车辆上。使用点质量方法对它们的作用方向进行建模，并提取用于确定最小水平曲线半径的方程式。