基于WIM的高速公路桥梁车辆疲劳荷载谱研究

Study on Vehicular Fatigue Load Spectrum Expressway Bridge Based on WIM System

为研究高速公路桥梁的实际车辆疲劳荷载谱，选取了京沪高速（G2）沂淮段新沂河大桥，基于动态称重系统（WIM）的监测信息，统计分析京沪高速沂淮段通行车辆的车重、车间距、轴重等特征参数；依据每月所得车辆数据，基于Miner线性积伤率和等效疲劳损伤原理，建立了新沂河大桥包含9类代表车型的实际运行车辆疲劳荷载谱，并对其疲劳损伤贡献值进行了研究。结果表明：各车道车重服从典型的三峰分布规律，车间距服从Weibull分布：六轴2类代表车，第1、2轴重服从典型Gauss分布，而第3～6轴重服从混合Gauss分布；车辆疲劳荷载谱值与疲劳损伤贡献值都以六轴2类车最大，其次为六轴车1类，可知该高速公路上以六轴重车为主，同时，对于疲劳损伤的贡献，六轴车占90％以上。

In order to study vehicular fatigue load spectrum for expressway bridge, based on the vehicle data collected from the weith-in-motion （WIM） system of Xinyihe Bridge on Yihuai section of Beijing - Shanghai expressway （G2）, the characteristic parameters, such as vehicle weight, headway and axle load and so on, are statistical analysed. According to the monthly vehicle data, the Miner＇s linear cumulative damage rate and the equivalent fatigue damage theory, the actual vehicular fatigue load spectrum for the bridge, which contains 9 vehicle types, is set up, and the contribution values of fatigue damage are also explored. The result shows that （ 1 ） the weights of vehicles in different lanes obey typical trimodal distribution, and the headways obey Weibull distribution; （2） for the second type of 6-axle vehicles, the first and second axle loads obey Gauss distribution, while the other axle loads obey mix Gauss distribution; （3） the vehicular fatigue load spectrum values and the contribution values of fatigue vehicles reach the maximum values, and the next is the first type vehicular loads on this expressway are mainly the 6-axle vehicle loads damage of the second type of 6-axle of 6-axle vehicles. It means that the , which account for more than 90% of the contribution values of fatigue damage.