高速公路小半径圆曲线横净距分析及改善措施研究

Research on Analysis and Improvement Measures for Horizontal Clearance of Small Radius Circular Curves of Expressways

在高速公路设计过程中,受限于地形、地质、生态红线和永久性基本农田等因素,有时会采用较小半径的圆曲线,圆曲线半径较小则可能会使曲线内侧紧邻中央分隔带车道的视距受到较大影响,致使横净距不足,进而影响行车安全性。对高速公路小半径圆曲线横净距进行分析研究,计算了标准横断面尺寸下80km/h、100km/h和120km/h设计速度的实际横净距和基于横净距要求的最小圆曲线半径,得出了不同设计速度和圆曲线半径下的横净距加宽值,提出了适用于不同情况下解决横净距不足的措施,为类似工程问题提供参考。

In the design process of expressways,due to factors such as terrain,geology,ecological red lines and permanent basic farmland and so on,smaller radius circular curves are used sometimes.A smaller radius of the circular curve may greatly affect the sight distance on the inner side of the curve adjacent to the medial strip,resulting in insufficient horizontal clearance and thus affecting the driving safety.The horizontal clearance of small radius circular curves of expressways is analyzed and studied.The actual horizontal clearance at design speeds of 80km/h,100km/h,and 120km/h under standard cross-sectional dimensions and the minimum circular curve radius based on horizontal clearance requirements are calculated,and the widening values of horizontal clearance under different design speeds and circular curve radii are obtained.The measures suitable for solving the insufficient horizontal clearance in different situations are put forward,so as to provide reference for similar engineering problems.