Measurement of Service Loading and Development of Monitoring System for Durability Evaluation of Highway Bridges due to Social and Economic Changes.

(1)在役交通荷载的测量及其工程应用开发了一种利用反力信号的桥梁动态称重系统，并将其应用于名古屋附近主要公路和高速公路的几个桥梁位置。基于Miner累积损伤准则，建立了桥梁疲劳损伤指标，并对不同车型对桥梁不同构件的损伤进行了评估。还开发了一种新的技术，其中桥梁振动与轴载和车辆重量同时测量，以将它们与交通引起的振动相关联。(2)公路桥梁和高架标志结构的监测从振动和应力循环的角度对高架标志结构和灯杆进行了监测，以便将振动与疲劳耐久性联系起来。视觉监测和简单的偏转仪也被应用到实际的灯杆，以评估其振动特性。还对这种高架标志结构的基础细节进行了疲劳试验。(3)焊接接头疲劳耐久性评价模型的建立对暴露于大气环境中约25年的未涂漆耐候钢焊接接头进行了疲劳试验。提出了利用有限元分析结果评估复杂焊接细节疲劳强度的一毫米法。通过低周疲劳试验，建立了钢在低周疲劳区的评价模型，并利用图像分析技术获得了相对准确的大应变。

(1) Measurement of Traffic Loading in Service and its Engineering ApplicationA Bridge Weigh-in-Motion system using signal corresponding to reaction force was developed, and it was applied to several bridge locations in major highway and expressways near Nagoya. Fatigue damage index based on Miner's cumulative damage rules was developed, and relative damages for different members of bridges caused by different truck types were evaluated. A new technique was also developed, where bridge vibration was simultaneously measured with axle load and vehicle weight to correlate them with traffic induced vibration.(2) Monitoring of Highway Bridges and Overhead Sign StructuresMonitoring of overhead sign structures and lighting poles was carried out from vibration viewpoint and stress cycles viewpoint in order to correlate vibration with fatigue durability. Visual monitoring and simple deflection meters were also applied to actual lighting poles in order to evaluate their vibration characteristics. Fatigue tests of base detail of such overhead sign structures were also carried out.(3) Development of Models for Evaluation of Fatigue Durability of Welded MembersFatigue tests were carried out for welded joint of unpainted weathering steel exposed to ambient air environment for about 25 years. So-called one-millimeter method, which used FEM analytical result, was developed to evaluate fatigue strength of complex welded detail. Low cycle fatigue tests was also carried out to develop evaluation model of steel in low cycle fatigue region, where image analysis was used to obtain large strain with relative accuracy.