高速公路下坡路段缓坡安全性设计研究  

Study on Design of Gentle Slope in Continuous Downhill Section of Expressway

作　　者：吴明先[1] 杨军超 林宣财[1] 潘兵宏[2] 吴善根[1] WU Ming-xian;YANG Jun-chao;LIN Xuan-cai;PAN Bing-hong;WU Shan-gen(CCCC First Highway Consultants Co.,Ltd.,Xi'an Shaanxi 710075,China;School of Highway,Chang'an University,Xi'an Shaanxi 710064,China)

机构地区：[1]中交第一公路勘察设计研究院有限公司,陕西西安710075 [2]长安大学公路学院,陕西西安710064

出　　处：《公路交通科技》2021年第9期92-97,104,共7页Journal of Highway and Transportation Research and Development

基　　金：中交科技基金项目[2018]05号。

摘　　要：高速公路下坡路段设置缓坡的目的是降低货车行驶的速度,减少制动毂使用,提高连续下坡路段的安全性,现有规范对连续下坡路段缓坡设计指标的规定不够详细,且缺乏不同缓坡最小长度的规定。根据当前货运主导车型的实际情况,选取东风DFL4251A15六轴铰接列车主导车型,对货车在下坡路段的受力状态进行分析,将发动机制动条件下保持货车匀速的下坡坡度作为缓坡临界纵坡,并提出了连续下坡路段货车采取不同制动档位时,不同运行速度对应的缓坡坡度值。根据受力分析结果和制动毂温度降温模型,分别提出了基于货车速度降低特性和制动毂降温特性的缓坡坡长。结果表明:发动机制动时货车保持匀速行驶的缓坡均小于规范规定值;基于货车速度折减特性的缓坡坡长均大于规范中最短坡长的规定值,说明缓坡设计最小坡长应根据缓坡的作用确定。The purpose of setting gentle slope on the downhill section of expressway is to reduce truck speed and the use of brake hubs, and improve the safety of the continuous downhill section. The current specifications are not detailed enough for the design indicators of gentle slopes for continuous downhill sections, and there is lack of regulations on the minimum length of different gentle slopes. According to the actual situation of current leading freight vehicle types, selecting the leading type of the Dongfeng DFL4251 A15 6-axle articulated train, the force state of the truck on the downhill section is analyzed. Regarding the downhill gradient that keeps the truck at constant speed under the engine braking condition as the critical longitudinal slope of the gentle slope, and the gentle gradient values corresponding to different running speeds when the truck adopts different braking gears on the continuous downhill section are proposed. according to the force analysis result and the brake hub temperature drop model, the gentle slope lengths corresponding to the speed reduction characteristics and brake hub cooling characteristics are proposed respectively. The result shows that(1) when the engine is braked, the gentle slopes on which the truck keeps running at constant speed are all less than the specified values in the specification;(2) the slope lengths of the gentle slopes based on the speed reduction characteristics of trucks are all greater than the specified value of the shortest slope length, indicating that the design of the minimum slope length of the gentle slope should be determined according to the function of the gentle slope.

关 键 词：交通安全 高速公路 缓坡设计 制动毂温度模型 连续下坡路段 坡度坡长 

分 类 号：U412.33[交通运输工程—道路与铁道工程]