运营状态下悬索桥钢桥面板疲劳效应监测与分析

MONITORING AND ANALYSIS OF FATIGUE EFFECTS ON STEEL DECK OF A SUSPENSION BRIDGE IN WORKING CONDITIONS

基于润扬大桥悬索桥7个月的长期疲劳效应监测结果,建立了铺装层-钢桥面板一体化疲劳分析模型,并研究了两类关键焊接细节的疲劳效应与车流量、环境温度间的相关性关系。结果表明,两类焊接细节的应力循环次数与车流量线性相关而与环境温度无关,等效应力幅与环境温度线性相关而与车流量无关。由疲劳设计指南推荐的疲劳效应计算模型得到的应力循环次数较监测结果偏低,顶板-纵肋焊接细节的等效应力幅与监测结果吻合良好而纵肋对接焊接细节的结果较为保守。上述分析结果为疲劳设计指南的进一步改进和完善提供参考和依据。

One integrated fatigue analytical model consisting of asphalt pavement layer and orthotropic steel bridge deck was established based on long-term fatigue effect monitoring results of Runyang Suspension Bridge in seven months. The correlations between fatigue effects of two pivotal welded joints and traffic flow as well as ambient temperature were then investigated respectively. The investigation results show that the number of stress cycles is merely in linear correlation with traffic flow, and is irrelevant with ambient temperature, in addition, the calculated number of stress cycles according to the fatigue computation model recommended by design code is lower than that by monitoring results. The equivalent stress amplitude of deck-rib is coincident with monitoring results while the equivalent stress amplitude of rib-rib welded joint is relatively conservative. The above results are beneficial and referential for further improvement and completion of design code.