平面交口竖向设计高程计算的中心点法

针对平面交叉口竖向设计常规方法设计结果存在折角、表面不平顺的问题,提出中心点法,采用高程函数曲线斜率连续的边界线及通过交叉口中心呈辐射状的高程计算线,根据相交道路坡度的一致性情况,以交叉口中心为转坡点设置具有相同外矢距的竖曲线,或以通过交叉口中心点的水平面为公切面设置抛物线,所得竖向设计表面平顺,消除了折线,设计质量得到明显提高。

Central Point Method for Elevation Calculating of Grade Crossing Vertical Design

In order to avoid crimps on the design surface and poor smooth area nearby the center of grade crossing by normal method in vertical design,the central point method was presented.By the border lines which have continuous slope rate of the altitude curve graph and the altitude calculating lines called radial lines which cross the center of the intersection,according to the coherence of midline's gradient direction of the intersectant roads,either the uniform vertical curve with the center of intersection as turning point or the unitive parabola with the common tangent horizontal plane was set up.The elevation of the design point was calculated and the vertical design surface was obtained.By the central point method,the surface crimps were eliminated and good smoothness in the center region was warranted,and design quality was improved clearly.