超载对RC梁桥疲劳可靠性的影响分析

Influence of vehicle overload on the fatigue reliability of reinforced concrete bridges

基于传统的用于疲劳可靠性分析的累积损伤模型和英国BS5400规范中标准疲劳车,以某钢筋混凝土梁桥为背景,研究了车辆超载对钢筋混凝土梁桥疲劳可靠度的影响和车辆超载与交通量增长同时作用下该钢筋混凝土梁桥疲劳可靠度的时变规律。研究结果表明:在相同的使用寿命情况下,超载水平越高,细节的疲劳可靠度指标越低,发生疲劳失效的概率相应也越大;同时考虑超载与交通量增长将大大缩短桥梁的疲劳寿命。与只考虑超载情况相比,服役后期细节的疲劳可靠度指标将急剧减小,桥梁在设计基准期内发生疲劳破坏的风险将显著增加。

Based on traditional model of cumulative fatigue damage and standard fatigue vehicles of British BS5400,a reinforced concrete bridge is taken as the engineering background,and the overloaded vehicles＇ effect on the fatigue reliability of reinforced concrete bridge and the time-variant law of the fatigue reliability are studied in details with the consideration of vehicle overload and traffic growth.The results show that the higher level of the overload is,the detail fatigue reliability will be lower and the probability of fatigue failure will be greater.Vehicle overload with traffic growth will greatly shorten the fatigue life of the bridge,compared with only considering the vehicle overload,the details of the service post-fatigue reliability will dramatically reduce,and the risk of fatigue failure will increase significantly,which can be as a reference for the bridge design.