护栏成本效益分析方法研究

Research on the Cost-benefit Analysis Method of Barriers

研究建立了包括车辆碰撞护栏事故数预测、车辆碰撞护栏后速度计算、单次碰撞损失计算、年总碰撞损失计算、护栏成本计算的护栏成本效益分析方法。车辆碰撞护栏事故数预测考虑年平均日交通量、是否双向分离、纵坡、平曲线、危险物与行车道边缘线的距离等因素。单次碰撞损失计算时,通过车辆碰撞能量与护栏设计防护能量的差值体现不同防护等级护栏的防护比例以及车辆碰撞护栏后速度,对应不同的碰撞严重性指数,得出不同护栏设置方案对事故损失的影响。以某路侧为1∶1.5填方边坡高度6m的二级公路为例,进行不同护栏设置方案的成本效益对比分析,以确定最优护栏设置方案,验证了方法的实用性和可行性。

In this paper,a cost-benefit analysis method for barriers is developed,which includes the accidents number prediction of vehicle impact with barriers and the calculation of vehicles speed after impact with barriers,single impact loss,total annual impact loss and barriers cost.The average daily traffic volume(AADT),bidirectional separation,grade,horizontal curve,the distance between dangerous objects and carriageway edge lines are considered in the accidents number prediction of vehicle impact with barriers.In the calculation of single impact loss,the difference between vehicles impact energy and barriers protection energy reflects barriers protection ratio of different protection levels and vehicles speed after impacting barriers,and then corresponds to different impact severity indexes,so as to achieve the influence of different barriers setting schemes on accident loss.Taking a secondary highway with a 1∶1.5 side slope height of 6 mas an example,comparative analysis of cost and benefit of different barriers setting schemes is carried out to determine the optimal guardrail setting scheme and verify the practicability and feasibility of the method.