Application of a regression model for predicting traffic volume from dynamic monitoring data to the bridge safety evaluation
Application of a regression model for predicting traffic volume from dynamic monitoring data to the bridge safety evaluation
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DOI：
10.1007/s13349-017-0234-7
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发表时间：
2017-08
影响因子：
4.4
通讯作者：
Kaiwan Wattana;M. Nishio
中科院分区：
文献类型：
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作者：
Kaiwan Wattana;M. Nishio
本文介绍了由统计模型得到的交通量估计值的检验和应用。该模型是由安装在一个在役斜拉桥上的结构健康监测（SHM）系统获得的动态响应构建的。SHM系统由加速度计、温度传感器和基于桥上安装的摄像头的交通计数系统组成。首先对模型的性能进行了评估，得出的结论是，所构建的回归模型用于从动态响应估计等效卡车数是适用的。然而，人们也认识到，交通条件，如通过车辆的数量和交通流的速度略有影响的估计精度。然后，利用有限元模型对统计模型中交通量与所采用动力响应之间的关系进行验证，以应用于桥梁安全性评估。有限元模型的分析结果表明，从仅受交通量变化影响的分析数据中获得的采用响应与测量结果一致，即，所采用的响应对交通量敏感。因此，它们是有效的，用于交通量的估计。在此基础上，以估算交通量作为运营荷载效应，计算目标桥梁的可靠性指标，并与设计规范中的设计荷载进行比较。基于估算交通量的桥梁可靠度能够提供运营荷载下的实际安全状况，比基于设计荷载的桥梁可靠度更有利于桥梁维修决策。
This paper presents the verification and application of estimated traffic volume obtained from a statistical model. The model was constructed from dynamic responses acquired by a structural health monitoring (SHM) system installed on an in-service cable-stayed bridge. The SHM system consists of accelerometers, temperature sensors, and a traffic-counting system based on installed cameras on the bridge. The model performance was firstly assessed, and it was concluded that the constructed regression model for estimating the number of equivalent trucks from the dynamic responses was applicable. However, it was also recognized that the traffic conditions such as the number of passing vehicles and the speed of traffic flow slightly affected the estimation accuracies. Then, the relationships between the traffic volume and the adopted dynamic responses in the statistical model were verified by using the finite element (FE) model in order to apply in the bridge safety evaluation. The analytical results from the FE model revealed that the adopted responses obtained from the analytical data affected by only the traffic volume variability corresponded with those from the measurement, i.e., the adopted responses were sensitive to the traffic volume. Therefore, they were valid for use in the estimation of traffic volume. After that, the reliability indices of the target bridge were calculated by using the estimated traffic volume as the operational load effects with comparison of those calculated from the designed load in the design standard. The bridge reliability based on the estimated traffic volume could provide the actual safety conditions under the operational load, and it contributed more to decision making in bridge maintenance than those based on the design load.