剪刀叉匝道在城市高架快速路中的应用——以襄阳市内环北线工程为例

The Application of Scissors Ramp in Urban Elevated Expressway—Taking Xiangyang Inner Ring North Line Engineering as an Example

我国快速路在城市内部高强度开发区域的建设形式主要是高架快速路。受用地和拆迁等因素限制,其与周边地块的交通联系通常以在干道路口设置菱形立交、利用上下桥匝道等方式实现。两相邻干道路口匝道多呈“先入后出”式,受城市道路网密度影响,横向道路距离普遍较近,进而导致高架路出入口交织段较短,出入流严重影响主线交通。剪刀叉匝道设置方案将原有“先入后出”式调整为“先出后入”式,避免了高架主线短距离交织运行,同时也有效地改善了地面交叉口的运行条件。文章以襄阳市内环北线工程为例,从保证交通功能和降低工程实施难度的角度出发,对匝道布置方案展开了分析,得出结论:所研究路段采用“剪刀叉匝道+主线调线”方案,交通功能及工程代价等方面综合考虑最优。研究过程可为类似条件下的匝道设计提供有益的借鉴和参考。

Elevated expressway is the main form of expressway construction in high-intensity development areas within cities in China.Restricted by factors such as land use and remove,its traffic connection with the surrounding plots is usually achieved by setting a diamond interchange at the intersection of trunk roads and using the upper and lower bridge ramps.Most of the ramps at the intersections of two adjacent trunk roads are"first in and then out".Affected by the density of urban road network,the distance between transverse roads is generally short,which leads to the short interleaving section at the entrance and exit of the elevated roads,and the inflow and outflow seriously affect the main line traffic.The scissors ramp setting scheme adjusts the original"first in and then out"type to"first out and then in"type,which avoids the short-distance interleaving operation of the elevated main line and effectively improves the operation conditions of the ground intersection.Taking Xiangyang inner ring north line engineering as an example,this paper analyzes the ramp layout scheme from the perspective of ensuring traffic function and reducing the difficulty of engineering implementation.It is concluded that the studied road section adopts the scheme of"scissors ramp+main line route adjustment",and the traffic function and engineering cost are comprehensively considered to be optimal.The research process can provide useful reference for ramp design under similar conditions.