基于货车制动安全的公路长大下坡可靠性设计方法

Reliability Design Method for Long Steep Downgrades Based on Trucks' Braking Safety

为了提高长大下坡路段的交通安全水平,提出了基于货车制动安全的公路长大下坡可靠性设计方法.以现行公路工程结构可靠度设计统一标准为依据,对纵坡可靠度进行定义,以货车制动器制动效能下降的临界安全温度作为约束条件,建立了货车下坡过程制动器温升模型的功能函数,推导了纵坡可靠性计算模型,提出了纵坡可靠性计算模型的求解方法.采用此方法并结合工程案例,得出了事故路段的可靠度.该结果示范了纵坡可靠性设计方法的应用,并验证了可靠性设计方法的合理性.最后,基于可靠性设计方法,计算了高速公路组合纵坡的不同平均纵坡值所对应的最大安全坡长.

Long steep downgrades are typical accident-prone highway sections. To solve this problem, a reliability design method for long steep downgrades based on the braking safety of truck was presented. Based on Unified Standard for Reliability Design of Highway Engineering Structures, the term of reliability of downgrade was defined. With the critical safety temperature of braking efficiency drop as a constraint,the performance function of brake’s temperature rising model was established. A model for calculating downgrade’s reliability was deduced and method for solving the model was put forward. Combined with an example,the reliability of the accident-prone highway sections was obtained. The results show that the application of the downgrade reliability design method is illustrated, and its reasonability is verified. Furthermore, with the reliabi litydesign method,the max imum safety grade length of combined downgrades of expressway was calculated.