【作者】 廖军洪；

【导师】 邵春福；

【作者基本信息】 北京交通大学 ， 城市交通工程， 2016， 博士

【摘要】 近年来,为满足社会经济快速发展的需要,高速公路建设重点已从东部平原微丘逐步向中西部山区重丘转移。受山区地形地貌、地质和社会经济等方面的限制,山区高速公路连续长大下坡路段的数量和长度不断增加,并呈现了与隧道群、桥隧群、螺旋隧道、高墩桥梁等特殊结构物组合的特征。同时,受高海拔的影响,连续长大下坡路段通常存在雾、冰雪、强侧风、强降雨等不利气候条件,车辆运行安全风险较大。调查表明,国内大多数连续长大下坡路段为事故相对多发路段,部分高速公路甚至因连续长大下坡路段导致的群死群伤事故而被称为“死亡之路”。尽管国内在连续长大下坡安全保障方面已经开展了大量研究,但针对线形指标的研究较薄弱,连续长大下坡路段的运营安全问题仍较严峻。因此,有必要针对高速公路连续长大下坡路段的线形设计和优化技术开展更深入和更具针对性地研究,为进一步提高连续长大下坡路段的运营安全风险防控能力提供技术支撑。本论文以高速公路连续长大下坡路段为研究对象,在分析连续长大下坡路段主要运营安全风险因子的基础上,针对连续长大下坡路段驾驶负荷与线形指标关系、纵断面指标优化技术、平纵线形组合优化技术开展研究,主要内容包括以下四方面：(1)连续长大下坡路段运营安全风险因子分析。从驾驶人行为、车辆状态、设施条件和交通环境等角度分析梳理了高速公路连续长大下坡路段主要存在的不利交通安全因素,建立了高速公路连续长大下坡路段运营安全风险因子清单,构建了连续长大下坡路段运营安全风险防控措施总体架构。(2)连续长大下坡路段驾驶负荷与线形指标关系研究。分析了车辆在连续长大下坡路段行驶时驾驶人的行车感受、车辆操作行为特征、不同展线形式下路径选择和安全设施使用效果的直观感受等特性,开展了高速公路连续长大下坡路段驾驶负荷实车试验,建立了高速公路连续长大下坡路段平纵线形指标与驾驶负荷的定量关系模型,提出了基于驾驶负荷的线形指标评估方法。(3)连续长大下坡路段纵断面指标优化研究·综合考虑连续长大下坡长度、平均纵坡、纵坡坡段组成、下坡速度、重载货车车辆特性和车辆总重等因素,采用制动器温升模型和基于TruckSim的车辆动力学仿真技术,分析了特定连续长大下坡路段货车下坡过程中制动器温度和制动力矩的变化趋势、货车不同轴之间制动力矩的分布特性以及坡段纵坡对货车制动力矩的影响和车辆总重、运行速度对货车制动器温度及制动力矩的影响,探讨了高速公路连续长大下坡路段采用单一纵坡下坡和设置缓坡两种展线形式对货车制动器温度和制动力矩影响的差异,提出了高速公路连续长大下坡路段区段划分的量化标准、纵坡设计和安全对策措施建议,为《公路工程技术标准》(JTG B01-2003)第3.0.17条的修订提供了支撑。(4)连续长大下坡路段线形组合优化研究。针对高速公路连续长大下坡路段道路环境特征,考虑平纵线形组合、驾驶人动态视觉特性、车辆运行速度和车前灯照射范围等因素,采用三维动态视距作为评估线形组合的关键指标,提出了基于三次B样条曲线的三维公路线形拟合方法。进一步以驾驶人视点和视距验算点的连线与视线中心线的夹角和驾驶人在该方向上最大动态视角的关系作为约束条件,建立了三维动态视距计算模型,提出了基于三维动态视距的高速公路连续长大下坡路段线形组合评价方法。更多还原

【Abstract】 To meet the requirements of the rapid development of social and economic in China, the emphasis of expressway construction has moved from eastern plain areas to middle and western mountainous areas. For the limitation of topography, geology and economic development, the number of long steep downgrades on expressways increases significantly. Moreover, combination of long steep downgrades and tunnel group, bridge-tunnel-bridge sections, spiral tunnels and high pier bridges is very common. Influenced by the high altitude, bad weather condition, e.g. fog, ice, snow, strong crosswind, often exists in long steep downgrades. Therefore, operation safety risks of long steep downgrades are higher than other road sections. According to the survey results, most long steep downgrades on domestic expressways are accident-prone sections. Influenced by the fatal accidents on long steep downgrades, some expressways are called "dead road". Although much research on safety enhancement of long steep downgrades has been conducted, operation safety problems still exist on long steep downgrades. So much more in-depth and targeted research on geometric design and the optimization techniques for long steep downgrades on expressways should be conducted based on current research findings, in order to improve the ability of operation safety risk prevetion and control of long steep downgrades.The focus in this dissertation is long steep downgrades on expressways. Based on the analysis of main operation safety risk factors for long steep downgrades, research from the aspects of the relation between driving workload and geometric alignment, optimization techniques of vertical alignment, combination of horizontal and vertical alignment is conducted.(1) Analysis of operation safety risk factors for long steep downgrades. Considering the factors of driving behaviors, vehicle conditions, highway infrastructures and traffic environment, main influence factors of traffic safety are analyzed and summarized. Then operation safety risk factors checklist for long steep downgrades on expressways is developed.(2) Research on the relation between driving workload and geometric alignment for long steep downgrades. Driving experiences, characteristics of vehicle control, routing selection and the effects of traffic safety facilities on long steep downgrades are analyzed. Then relational model between geometric alignment and driving workload is developed based on the site and real vehicle tests of driving workload on long steep downgrades. Moreover, the geometric alignment evaluation techniques for long steep downgrades on expressways based on driving workload is put forward.(3) Research on the optimization of profile design parameters for long steep downgrades. Considering the factors of the longitudinal grade composition of long steep downgrades, characteristics of heavy trucks, operating speed, gross vehicle weight, etc., characteristics of brake temperature and brake torque of heavy trucks descending the grade are put forward, using brake temperature prediction model and vehicle dynamics simulation techniques based on TruckSim. The distribution characteristics of brake torque among different axles of heavy trucks are analyzed. Then the influence of gross vehicle weight and operating speed on brake temperature and brake torque of heavy trucks, as well as the influence of grade percentage of each section of long steep downgrades on brake torque is analyzed. Moreover, influence of two different profile design alternatives on brake temperature and brake torque of heavy trucks is discussed. The first design scheme is that unique longitudinal grade is used throughout the whole downgrade. The second one is that different grade percentages are used in different segments, e.g. a steep grade is preceded by a gentle slope. Finally, the quantified section classification criterion and recommendations for the profile design of long steep downgrades on expressways are provided. The research findings have been proved to support the amendment of article 3.0.17 of Technical Standard of Highway Engeering (JTG BO 1-2003).(4) Research on the optimization of geometric alignment combination for long steep downgrades. Considering the factors of three-dimensional (3D) highway alignment, drivers’ dynamic visual field, the illumination angle of vehicle headlamps etc.,3D dynamic sight distance is used to evaluate the combination of horizontal and vertical alignment of long steep downgrades on expressways. Firstly, the 3D highway alignment fitting methods based on cubic B spline curves are put forward. Secondly, the calculation model of 3D dynamic sight distance is developed with the constraint of the relation between the computed angle composed by the line from the position of drivers’ eyes to the sight distance checking point and the centerline of drivers’ visual field, and drivers’ maximum dynamic visual angle. Finally, the evaluation technique of geometric alignment combination of long steep downgrades on expressways based on 3D dynamic sight distance is provided.更多还原