用于公路桥梁可靠性评估的车辆荷载多峰分布概率模型

通过对京沪高速公路车辆运行状况的实测和统计分析,发现由于汽车工业的发展以及超载现象的存在,实测的车辆荷载呈现出多峰分布的特性,难以用传统的单峰概率分布模型来描述.利用极值型Ⅰ分布函数和正态分布函数的加权和,拟合得到了由轻型车辆、普通车辆和重型(含超载)车辆所组成的多峰型车辆荷载的概率分布函数.通过滤过复合Possion过程和滤过复合Weibull过程分别对一般运行状态和密集运行状态下的车辆荷载过程进行了模拟.最终以后续服役期内轻型车辆、普通车辆和重型(含超载)车辆荷载最大值分布的0.95分位值作为桥梁在剩余可靠度研究的评估荷载.该多峰型车辆荷载模型更符合实际,提高了桥梁剩余可靠度评估的准确性和合理性.

Multiple-peaked probabilistic vehicle load model for highway bridge reliability assessment

Statistics of acquired traffic load data from Jinghu Highway in China show that the actual vehicle loads follow a multiple-peaked distribution rather then the traditional single-peaked probability distributions.In this paper,the multiple-peaked distribution of vehicle loads is modeled by the weighted sum of one extreme distribution and two normal distributions,which represents the load of light vehicles,normal vehicles and heavy(including overload) vehicles,respectively.A filtered compound Poisson process and a filtered compound Weibull process are used to describe the vehicle load process in normal traffic state and dense traffic state,respectively.Finally,the 0.95 fractals of the maximum distributions for three types of vehicle loads are proposed as the evaluation loads for the reliability assessment of highway bridges in their residual lives,making the reliability assessment more rational and precise.