基于碳化的预应力组合箱梁桥可靠性分析

Reliability analysis of prestressed composite box girder bridge based on carbonation

为了研究预应力混凝土结构在混凝土碳化后,结构在服役期间的可靠度,分析讨论了混凝土碳化及其影响因素。将混凝土强度、保护层厚度、计算模式不确定性系数以及荷载增长系数作为随机变量,以混凝土的碳化深度作为一个随时间变化的随机过程,建立了一般大气环境下,混凝土碳化的时变概率随机模型。在此基础上,对五跨预应力组合箱梁进行了研究,从可靠度方面给出了在服役期间结构的可靠度水平。

In order to investigate the reliability of existing prestressed concrete construction on the condition of concrete carbonation, the mechanism of concrete carbonation and influencing factors are discussed and analyzed in the paper. A time-varying probabilistic stochastic model of concrete carbonation in common atmosphere environment are established by considering concrete strength, the thickness of concrete cover, the uncertainty coefficient of computation mode and the growth factor of load as random variables and concrete carbonation depth as a random process with time changes. Based on that, a five-span prestressed composite box girder is studied,the reliability level of construction is computed in the different service period from reliability.