基于WIM的典型城市桥梁车辆荷载状况分析

基于安装在杭州石祥路留石高架上的动态称重系统（WIM）采集的交通流和车辆荷载数据,通过对交通流量、车辆构成、轴重、车辆总重等进行分析,获取了其概率统计特性及分布规律,建立了轴载谱和车辆总重谱,并与相关文献、规范进行了比较。结果表明：一天中各时段的交通流量具有很强的潮汐规律性;2.86%的车辆轴重超过了10 t的超载标准,最大的单轴重量达39.5 t,最大车辆总重达115 t,后半夜车辆恶性超载严重;2轴车车辆总重表现为单峰分布,3轴以上车辆的总重均表现为多峰分布,5轴车和6轴车的总重表现为3峰分布;轴重大的车辆主要是超载的2轴、3轴车辆,这部分车辆对桥梁等基础设施的危害较大。这些车辆荷载特征的获取有助于区域既有桥梁安全性的合理评估,为超重车辆治理和桥梁安全管理提供帮助。

Statistical Analysis of Site-specific Traffic Load Using Weigh-in-Motion Data

This paper is concerned with statistical analysis of the traffic data and develoTP a site-specific traffic load model based on the weigh-in-motion（ WIM） system installed in Hangzhou Shixiang Expressway Bridge. The traffic condition and vehicle loading are analyzed in terms of vehicle traffic volume,vehicle traffic composition,axle load spectrum and gross vehicle weight spectrum. The results show that： traffic flow has a strong tidal regularity; 2. 8% of the vehicles have their axles overloaded by 10 tons or above,the maximum axle weight is 39. 5 tons,the maximum gross vehicle weight is 115 tons,the problem of aggravated overloading in the small hours is serious. Two-axis vehicle＇s GVW showed a unimodal distribution,three-axis above the GVW are expressed as multimodal distribution,five-axis and six-axis vehicle ＇s GVW showed tri-modal distribution. In heavy-axled vehicles,overloading mainly occurs on the second and / or the third axles,which might compromise the integrity of the structures of the bridge and other infrastructures. The acquisition of characteristics of vehicle loads helTP to make fair assessments of the safety of the bridges in service in the area, assisting the control of overloaded vehicles and management of bridge safety.