高速公路纵坡坡长可靠性设计研究  

Study on Reliability Design of Expressway Longitudinal Slope Length

作　　者：张航[1] 田晟 李明 ZHANG Hang;TIAN Sheng;LI Ming(School of Transportation,Wuhan University of Technology,Wuhan Hubei 430000,China;Jiangsu Zhongshe Group Co.,Ltd.,Wuxi Jiangsu 214000,China)

机构地区：[1]武汉理工大学交通学院,湖北武汉430000 [2]江苏中设集团股份有限公司,江苏无锡214000

出　　处：《公路交通科技》2022年第7期75-83,共9页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51678460);湖北省交通运输厅科技项目(2014-721-2-7)。

摘　　要：针对我国现行规范《公路路线设计规范》(JTG D20—2017)在高速公路纵坡设计中仅对最大纵坡及最大坡长做出限制要求,通过分析道路纵坡设计的影响因素并考虑汽车实际在上坡过程中的运动状态,建立了坡长的功能函数;引入可靠度理论,将可靠概率与失效概率作为表征可靠度的指标,采用蒙特卡洛法计算了在120,100,80 km/h共3种设计速度对应的最大纵坡坡度条件下,不同坡长供给值的失效概率,并指出存在隐患的设计指标。然后根据《公路工程结构可靠性设计统一标准》(JTG 2120—2020),为满足高速公路对应安全等级的可靠度要求,对不同坡长供给值下的可靠度进行独立计算,将可靠度概率大于95%的坡长供给值作为安全坡长建议值,从而提供了阶梯坡度范围内坡长的限制要求。结果表明:在相同坡长供给值条件下,纵坡可靠度概率值随着坡度的增大而减小;当设计速度为120 km/h时,对应最大纵坡坡度为3%的最大坡长可靠度概率为95.581%,安全建议坡长计算值为900 m,与规范一致。当设计速度分别为100 km/h和80 km/h时,对应最大纵坡坡度为4%,5%的最大坡长可靠度概率为86.555%,74.874%;对应最大纵坡坡度为4%,5%的安全建议坡长计算值分别为700 m和500 m,均小于规范值。最后运用工程实例研究了事故率与设计值失效概率的关系,设计值失效概率越大,越容易引发交通事故,推行基于可靠度理论计算得到的纵坡坡长值进行高速公路设计,可提高道路安全性。According to Chinese current Design Specification for Highway Alignment(JTD D20—2017), only the maximum longitudinal slope and maximum slope length are restricted in the expressway longitudinal slope design. By analyzing the influencing factors of the road longitudinal slope design and considering the vehicle actual motion state during uphill driving process, the functional function of slope length is established. By introducing the reliability theory, taking reliability probability and failure probability as the indicators to characterize reliability, the failure probabilities of supply values of different slope lengths under the conditions of the maximum longitudinal slope at the design speeds of 120, 100, 80 km/h are calculated by using Monte Carlo method, and the design indicators with hidden dangers are pointed out. Then, according to the Unified Standard for Reliability Design of Highway Engineering Structures(JTG 2120—2020), in order to meet the reliability requirements of the corresponding safety levels of expressway, the degrees of reliability with different slope lengths are calculated independently, and the slope length with a reliability probability greater than 95% is taken as the recommended value of the safe slope length, thereby providing the limit requirements for the slope length within the range of step slope. The result shows that(1) under the condition of the same given slope length, the reliability probability of the longitudinal slope decreases with the increase of the slope;(2) when the design speed is 120 km/h, the maximum slope length reliability probability corresponding to the maximum longitudinal slope of 3% is 95.581%, and the recommended safety slope length calculation value is 900 m, which is consistent with the specification;(3) when the design speed is 100 km/h and 80 km/h, the reliability probability of the maximum slope length corresponding to the maximum longitudinal slope of 4% and 5% is 86.555% and 74.874%, and the recommended safety slope lengths corresponding to the ma

关 键 词：道路工程 失效概率 可靠度 纵坡坡长 交通安全 

分 类 号：U412.3[交通运输工程—道路与铁道工程]