既有钢筋混凝土梁桥可靠度分析

摘要

既有钢筋混凝土梁桥在运营过程中,由于混凝土碳化,钢筋锈蚀造成承载能力降低,影响结构的安全性。将可靠度评估中的抗力和荷载效应考虑为随时间变化的随机过程,通过对结构抗力衰减影响因素的分析,建立抗力的随机过程模型,根据统计资料建立作用在桥梁上的荷载效应模型。然后运用可靠度理论的计算方法对桥梁结构构件动态可靠度进行了分析,并对一座既有钢筋混凝土简支梁桥进行了实例分析。%For existing reinforced concrete beam bridge,due to reinforcement corrosion and concrete carbonation,its load capacity has been decreased.The resistance and load effect can be considered to be stochastic process.Through analyzing the influencing factors of resistance reduction,the resistance model can be established.The load effect model can be obtained according to some statistical data.Then,the reliability theories are used to assess the time-dependent reliability of bridge.After that,a case study of an existing simple supported reinforced concrete bridge is given to demonstrate the method.