基于合成坡度的连续下坡路段货车行车风险评价方法

Risk Assessment Method for Trucks on Continuous Downhill Section Based on Synthetic Slope

为了分析高速公路连续下坡平纵组合路段的货车行车风险要素及其影响情况,提出了合成坡度和制动毂温度风险因素,利用货车事故率量化行车风险,研究了风险因素交互作用。首先,基于制动距离表征制动效能的角度,通过行车动力学仿真试验发现了货车制动衰退与道路的合成坡度在影响货车平纵组合路段行车风险方面存在一定交互作用。然后,以2013—2020年雅西高速公路3处连续下坡路段原始交通数据处理与分析为基础,基于实际事故数据,通过聚类及相关性分析方法揭示了合成坡度-制动毂温度-货车事故率内在的指数增长相关性。最后,采用非线性回归法拟合了相关性曲面函数,择优构建了货车事故风险度量方程,结合风险分级标准提出了高速公路连续下坡路段货车行车风险评价方法并进行了实例验证。结果表明:二元非线性指数函数能够较好地解释货车在连续下坡平纵组合路段发生的事故风险变化规律,通过对风险模型剖析,合成坡度与制动毂温度的交互作用主要体现在合成坡度5%以上和制动毂温度200℃以上的组合路段,交互作用导致货车行车风险的急剧增大。研究结果可为高速公路连续下坡路段道路线形优化、安全措施布设尤其是避险车道布设提供有效的参考依据。

In order to analyze the factors of truck driving risk and their influence on the continuous downhill section of the expressway,the synthetic slope and brake hub temperature risk factors are put forward,the truck accident rate is used to quantify the truck driving risk,and the interaction of risk factors is studied.First,the angle of braking efficiency is represented based on the braking distance,through the dynamic simulation test,it is found that there is a certain interaction between the degradation of braking and the synthetic slope on the road.Then,based on the original traffic data processing and analysis of three continuous downhill sections of Yaan-Xichang Expressway from 2013 to 2020,based on the actual accident data,through clustering and correlation analysis,the inherent exponential growth correlation of synthetic slope-brake hub temperature-freight car accident rate is revealed.Finally,the correlation surface function isfitted by the nonlinear regression method,and the risk assessment equation of truck accident is constructed,combined with the risk classification standard,the evaluation method of freight car running risk in the continuous downhill section of expressway is put forward,and the example verification is carried out.The result shows that the binary nonlinear exponential function can well explain the change rule of accident risk of freight cars on the straight and vertical combination road sections of continuous downhill,the interaction between the synthetic gradient and the temperature of the brake hub is mainly embodied in the road sections with the synthetic gradient above 5%and the temperature of the brake hub above 200℃.The research result can provide an effective reference for the optimization of expressway alignment,the layout of safety measures,especially the layout of the refuge lane.