基于三维线形运行速度的山区旅游公路线形安全性评价

Safety Evaluation of Mountain Scenic Highway Based on Operating Speed of Three-Dimensional Alignment

公路线形设计的安全性评价常采用运行速度作为评价指标,针对山区旅游公路的复杂线形及车型构成,运行速度的计算工况应有针对性,计算手段也需改进。将洪雅—峨眉山旅游公路作为分析对象,以"三维线形条件下的复杂道路重载车辆行驶速度解算模型体系"为计算手段,针对长大纵坡路段左、右线的交通特点,分别解算并绘制了三维线形条件下典型车型和典型驾驶模式的运行速度曲线;分析了平纵面线形参数的协调性和安全性,提出线形修改建议;对于线形调整困难的情况,采用仿真模拟碰撞对混凝土护栏进行防护等级加强;同时检查了避险车道的设置。研究结果表明,综合道路空间线形、车型、驾驶员等因素进行系统分析和运行速度预测,能更接近实际地评价和改善山区公路的线形设计。

Operating speed is often taken as an evaluation indicator in safety evaluation of highway alignment design. In consideration of the complex alignment and vehicle types of mountain scenic high- ways, the calculation condition of operating speed should be pertinent and the calculation means should also be improved. The operating speed curves of typical vehicle types and typical driving modes under the three-dimensional alignment conditions were predicted respectively by selecting the Hongya--Emei Scenic Highway as the object, applying the ＂operating speed prediction model system of heavily-loaded vehicles on complex mountainous highways under the three-dimensional alignment conditions＂, and con- sidering the transport characteristics of the left and right lanes at the long steep grade. The coordination and safety of horizontal and vertical alignment parameters were analyzed, and the suggestions on align- ment modification were proposed. In respect of the difficulty in alignment adjustment, analogue simula- tion collision was adopted to strengthen the protection class of the concrete guardrails. The setting of the truck escape ramps was also checked. The research results show that the alignment design of mountain highway can be evaluated and improved in a more practical way by making an operating speed forecast based on the systematic analysis integrating highway spatial alignment, multiple vehicle types, the driver and other factors.