高速公路桥梁随机车辆荷载谱

Investigation on the random vehicle load spectrum of the highway bridge

以吉茶高速公路矮寨大桥为工程背景,进行了为期48h的随机荷载调查与研究。研究结果表明,该桥车辆荷载主要是以第二类小轿车和第七类大型货车为主,其中,小轿车占总车辆的49.51%,大型货车占总车辆的21.56%,其余类型车辆所占的比例均小于10%;第一类至第七类车型的典型车重分别为1 646,1 451,3 572,12 395,6 974,29 104,52 832kg。在此基础上,将每种类型的车辆折算成第七类车大型货车进行分析,从而得到折算后的车辆荷载的时间序列,然后再通过MATLAB编程获得车辆荷载的自相关函数和车辆荷载的功率谱密度函数。对折算后服从正态分布的随机车辆数据分别求出其均值和标准差,利用MATLAB编程来模拟高斯随机过程,最后得到矮寨大桥随机车辆荷载谱。研究成果可为高速公路桥梁的荷载谱编制和耐久性评估提供依据。

48 hours’investigation of traffic flows on Aizhai bridge in the Jicha highway was carried out.The survey revealed the vehicle load was mainly composed of the cars and the large trucks,of which the cars account for 49.5 1%,the large trucks account for 21.56%and the rest account for less than 10% of total vehicles.The typical vehicles’weight of seven categories are 1 646,1 45 1,3 572,12 395,6 974,29 104 and 52 832 kg respectively.And then analysis survey data by converting all classes vehicles’flow into large trucks’flow,the vehicle load time series was obtained,and utilize MATLAB software calculated the power spectral density function and the autocorrelation function.Due to Aizhai Bridge’s random traffic follow normal distribution function,the average value and standard deviation of ran-dom traffic could be found out.The Gauss process was used to describe the vehicle load ran-dom process,eventually the random vehicle load spectrum of Aizhai bridge was obtained. These research achievements can be used as references for the establishment of vehicle load spectrum and evaluation of durability in highway.