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为研究货运繁重公路的车辆荷载谱和疲劳车辆模型,基于佛山平胜大桥的动态称重系统采集的多时段车流数据,归类出了车辆荷载谱的10类代表车型,分析了代表车型的轴距、质量、轴重和超载数据,以及沿不同车道的车辆和轴重分布特性,提出了可用于钢桥疲劳评估的车辆荷载谱;以疲劳加载率最大的六轴车辆为原型,基于疲劳损伤等效原则分别提出了桥梁单向重载车道的疲劳车辆模型和简化疲劳车辆模型。计算结果表明:平胜大桥呈现货运繁重公路的典型特征,车辆日均通行总量达到了45 065veh,约为《AASHTO LRFD》定义的日均通行量20 000veh的2.3倍;疲劳车辆在全部交通流中的比例为51.6%,为《AASHTO LRFD》定义的20.0%的2.6倍;货车占疲劳车辆总数的45.2%,主要分布于重载车道,而且通行货车超载比例占到相应车型的30%~70%,最大超载货车达到了132.5t;两轴货车超载率为29.0%,等效质量达到17.5t,后轴等效轴重达到12.1t,因而不能忽略两轴货车的疲劳加载贡献。对比《AASHTO LRFD》五轴标准疲劳车辆模型(前轴轴重为2.6t,中间双联轴和后面双联轴的单轴轴重均为5.4t)和简化标准疲劳车辆模型(前轴为2.6t,中轴和后轴均为10.8t),提出的六轴单向疲劳车辆模型总质量为33.1t,前轴轴重为3.6t,中间双联轴和后面三联轴的单轴轴重均为5.9t;简化单向疲劳车辆模型的前轴轴重为3.6t,中轴和后轴分别为11.8、17.7t;针对重载车道提出的六轴疲劳车辆模型总质量达到了36.5t,前轴轴重为4.0t,联轴中的单轴轴重均为6.5t;对应的重载车道简化疲劳车模型的前轴轴重为4.0t,中轴和后轴轴重分别为13.0、19.5t。
In order to study the vehicle load spectrum and fatigue vehicle model of heavy road freight traffic, based on the multi-period traffic flow data collected by the dynamic weighing system of Ping Sheng Bridge in Foshan, 10 representative models of vehicle load spectrum are classified. The vehicle load spectrum which can be used for the fatigue assessment of steel bridge is proposed based on the data of vehicle mass, axle load, axle load, distance, mass, axle load and overloading data, and the distribution characteristics of vehicle and axle load along different lanes. Based on the fatigue damage Equivalence principle is put forward respectively for the fatigue vehicle model and simplified fatigue vehicle model for one-way heavy-load lane of bridge. The calculation results show that the Ping-Sheng Bridge presents the typical characteristics of the heavily loaded freight road with an average daily traffic volume of 45 065 veh, which is about 2.3 times of the average daily traffic of 20 000 veh as defined by “AASHTO LRFD”. In the whole traffic flow 51.6%, 2.6 times 20.0% as defined by “AASHTO LRFD”; trucks account for 45.2% of the total number of tired vehicles, mainly distributed in heavy-load lanes, and the proportion of overloaded trucks accounts for 30% ~ 70% of the corresponding models %, The maximum overloaded truck reached 132.5t; the overloading rate of two-axle truck was 29.0%, the equivalent mass reached 17.5t, and the equivalent axle weight of the rear axle reached 12.1t, therefore, the fatigue loading contribution of two-axle trucks could not be neglected. Contrasting the “AASHTO LRFD” five-axis standard fatigue vehicle model (with a front axle with a shaft weight of 2.6 t and a single-axle axle with a double axle with a double axle of 5.4 t) and a simplified standard fatigue vehicle model with a front axle of 2.6 t, the center axis and the rear axis are 10.8t), the total mass of the proposed six-axle one-way fatigue vehicle model is 33.1t, the front axle shaft weight is 3.6t, the single shaft weight of the intermediate double shaft and the rear triple shaft 5.9t; simplified one-way fatigue vehicle model front axle shaft weight of 3.6t, the central shaft and the rear axle were 11.8,17.7t; for heavy lane proposed six-axle fatigue vehicle model total mass reached 36.5t, before The axle weight is 4.0t, the uniaxial axle weight in the joint shaft is 6.5t; the axle load of the front axle of the corresponding heavy-duty lane fatigue model is 4.0t, the axle load of the center axle and the rear axle are respectively 13.0,19.5 t.