车辆荷载下多车道横向折减系数的计算和分析

Calculation and Analysis of Multi-lane Transverse Reduction Factor under Vehicle Load

根据近几年我国主要干道的车辆荷载实测数据,对不同测点的车辆总重进行了统计分析,建立了不同测点车辆荷载的总体概率模型及截尾概率模型。在此基础上,采用概率方法对车辆荷载服从非正态分布的多车道横向折减系数进行了计算和分析,给出多车道横向折减系数建议值,并与规范规定的数值进行对比。结果表明:不同测点车辆荷载的总体概率分布服从多峰分布,概率密度函数可用1个对数正态和3个正态概率密度的加权和表示;左截尾概率分布服从对数正态分布。设计基准期内最大值的概率分布服从对数正态分布。车辆荷载按多峰分布计算的三车道、四车道、五车道、六车道、七车道、八车道横向折减系数分别为0.95,0.85,0.78,0.74,0.73,0.69,车辆荷载按截尾分布计算的三车道、四车道、五车道、六车道、七车道、八车道横向折减系数分别为0.86,0.73,0.62,0.57,0.56,0.50,均不小于《公路桥涵设计通用规范》规定的数值。

Based on the vehicle load data measured in major road of China in recent years, the gross weight models with overall probability distribution and truncated probability distribution of vehicle load at different measuring points are developed. Based on these probability models, the multi-lane transverse reduction factors of the vehicle loads subject to non-normal distribution are calculated and analyzed by probability method, and the recommended values of multi-lane transverse reduction factor are given and compared with the values of reduction factors in the specification. The analysis result indicates that （1） the overall probability distribution of vehicle loads in different areas follows a multi-peak distribution, the probability density function can be expressed by the weighted sum of a lognormal normal probability density and 3 normal probability densities; （2） the left truncated probability distribution follows lognormal normal distribution, the maximum probability distribution in design reference period follows lognormal normal distribution; （3） the transverse reduction factors of vehicle loads of 2-lane, 3-lane, 4-lane, 5-lane, 6-lane, 7-lane, and 8-lane calculated by multi-peak distribution are 0. 95, 0. 85, 0. 78, 0. 74, 0. 73, 0. 69 respectively, and the transverse reduction factors of vehicle loads of 2-lane, 3-lane, 4-lane, 5-lane, 6-lane, 7-lane, and 8-lane calculated by left truncated distribution are 0. 95, 0. 85, 0. 78, 0. 74, 0. 73, 0. 69 respectively, all of which are not less than the values specified in General Code for Design of Highway Bridges and Culverts.