The use of micro-simulation for congested traffic load modeling of medium- and long-span bridges
The use of micro-simulation for congested traffic load modeling of medium- and long-span bridges
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DOI：
10.1080/15732471003640477
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发表时间：
2012-04
影响因子：
3.7
通讯作者：
E. J. O’Brien;A. Hayrapetova;C. Walsh
中科院分区：
文献类型：
--
作者：
E. J. O’Brien;A. Hayrapetova;C. Walsh
本文提出了一种大跨度桥梁拥堵交通荷载事件建模的新方法。传统的交通负荷模型基于非拥堵交通的动态称重数据，或类似于泊松到达过程的数据。在这两种情况下，它们都没有考虑到交通拥堵时车道之间的混合。如图所示，随着交通减速，汽车从卡车之间驶出，导致大桥慢车道上卡车长龙的频率更高。这些较长的排在慢车道下增加了一些特有的负荷效应，虽然幅度不大，但幅度很大。微观模拟是在交通建模中广泛使用的单个车辆的建模过程，它是一种更准确地预测大跨度桥梁上的交通荷载的手段。拥堵的桥梁上的交通流是使用每个车道上卡车和小汽车的随机混合过程来建模的，其中每辆车被单独地建模，并在蒙特卡罗过程中随机分配驾驶员行为参数。在多个模拟公里内，车辆以模拟换道操作在车道之间移动。该算法是根据荷兰一座桥上的交通视频记录进行校准的。然后将桥梁上实测应变的极值统计量与相应的模拟统计量进行比较，以验证模型的有效性。微观仿真算法表明，换道对货车排长直方图有中等程度的影响。这反过来又会影响桥面的一些特征荷载效应。
This paper presents a new approach to the modelling of congested traffic loading events on long span bridges. Conventional traffic load models are based on Weigh- In-Motion data of non-congested traffic, or something similar to a Poisson Arrival process. In neither case do they account for the mixing between lanes that takes place as traffic becomes congested. It is shown here that cars move out from between trucks as traffic slows down which results in a higher frequency of long platoons of trucks in the slow lane of the bridge. These longer platoons increase some characteristic load effects under the slow lane by a modest but significant amount. Micro-simulation, the process of modelling individual vehicles that is widely used in traffic modelling, is presented here as a means of predicting imposed traffic loading on long-span bridges more accurately. The traffic flow on a congested bridge is modelled using a random mixing process for trucks and cars in each lane, where each vehicle is modelled individually with driver behaviour parameters assigned randomly in a Monte Carlo process. Over a number of simulated kilometres, the vehicles move between lanes in simulated lane-changing manoeuvres. The algorithm was calibrated against video recordings of traffic on a bridge in the Netherlands. Extreme value statistics of measured strains on the bridge are then compared to the corresponding simulation statistics to validate the model. The micro-simulation algorithm shows that the histograms of truck platoon length are moderately affected by lane changing. This in turn is shown to influence some characteristic load effects of the bridge deck.