高速公路桥梁收费站前拥堵车辆荷载评估

Assessment of Traffic Congestion Load at Expressway Toll Station

因收费排队,使得桥上汽车间距减小,桥梁全宽、全长满布荷载及行车集中制动的概率大大增加,实际运营状态的汽车荷载分布模式与规范规定的荷载有很大区别。该文以《公路桥涵设计通用规范》(JTJ 021-89)的荷载模式为基础,根据收费广场荷载分布的特殊性,对实际交通状况进行了调研、统计和分析;研究了因交通量增加、大吨位车辆多和轴荷分布变化引起的汽车活载修正,汽车荷载横向分布系数的修正,汽车纵向布置的调整,以及汽车制动力系数的调整等内容。某大桥引桥桥头段拟改、扩建为收费广场,按前述分析为基础建立了新荷载标准(模式),为大桥旧桥改造和新建拼宽结构进行评估提供依据。该实例可供同类工程参考。

The toll line makes the distance between vehicles on bridge decrease,and the full width and the full length of bridge are full of load,and the centralized braking probability of driving greatly increases.The actual vehicle load distribution mode of operating condition is different from the specification.Based on the load mode in the General Code for Design of Highway Bridge Culvert(JTJ 021-89),and according to the particularity of load distribution in toll square,the article investigates,gather statistics and analyzes the actual traffic status,and studies the correction of vehicle live-load,the correction of vehicle load transverse distribution coefficient,the adjustment of vehicle longitudinal arrangement and the adjustment of vehicle braking force coefficient caused by the increment of traffic volume,more large-tonnage vehicles and axle load distribution variation.The bridge head section of an approach bridge is proposed to extend and reconstruct into the toll square.The new load standard is set up according to the former analysis in order to provide the basis for the assessment of the reconstruction and the new built widened structure of the old bridge.