铆接钢桥剩余寿命与使用安全评估实例

将确定性与概率性评估方法应用于上海市浙江路桥剩余寿命安全评估．基于Monte-Carb法实NT应力谱模拟．按Miner准则估算了构件检测优先级．采用简化断裂力学模型计算了剩余寿命与探测间隔．在合理确定随机变量参数取值和目标可靠度基础上，应用Monte-Carlo法实NT桥构件和结构系统疲劳可靠度计算，并确定了概率性探测间隔．评估结果表明，结构系统疲劳可靠度、探测间隔要比单个构件的低．确定性与概率性评估结果为该桥维护决策提供了依据．

Assessment Methods of Remaining Fatigue Life and Service Safety of Riveted Steel Bridges

Deterministic and probabilistic fatigue assessment methods were adopted to evaluate the remaining fatigue life and service safety of in Shanghai riveted steelbridges. The stress spectrum was calculated on the basis of the statistic traffic data with Monte-Carlo method. Traffic load spectrum was derived from the comparison between field measurement and the calculated one. Linear fatigue-damage accumulation analysis approach was applied to calculating the fatigue life, and the damage degrees of different members showed a list of inspection priority. Remaining fatigue life and safe inspection intervals were determined on the basis of fracture mechanics model. Uncertainties associated with fatigue failure models and target fatigue reliability index were quantified. Based on Monte-Carlo method, fatigue reliability index of members and system were calculated, also safe inspection intervals were determined. Assessment results showed fatigue reliability and inspection intervals of system were lower than those of truss members. Strategies of maintaining riveted steel bridges thus were determined.