既有钢筋混凝土桥梁模糊随机可靠性评价

由于钢筋锈蚀、混凝土碳化和日益增加的交通荷载影响,桥梁性能随着时间劣化,可靠性降低。因此,在分析影响既有钢筋混凝土桥梁可靠性不确定性因素的基础上,将这些因素归结为随机性和模糊性,以模糊随机变量为基本变量,考虑桥梁在服役过程中的耐久性损伤对可靠性的影响,针对既有桥梁荷载的分析背景同拟建桥梁的不同,进一步考虑模糊性,建立了考虑失效准则模糊性的模糊随机状态方程,将JC法改进用于计算模糊随机可靠指标,以装配式简支梁桥可靠性评价为例给出了具体方法和过程。

Fuzzy Random Reliability Evaluation of Existing Reinforced Concrete Bridges

Bridges deteriorate with time due to reinforcement corrosion,concrete carbonization and ever-increasing traffic loads.This results in reduction of their reliability.Based on analysis for uncertainty of the factors influencing their reliability,which are regarded as randomness and fuzziness.Fuzzy random variable is introduced.Durability damage is incorporated into reliability evaluation during active time of bridge.Fuzziness is taken into account in load model due to the difference between existing and constructing bridge load.The fuzzy random limit state equation subjecting to fuzzy failure criterion is founded.The JC method is improved to compute the fuzzy random reliability index.The total reliability evaluation method and process are demonstrated by an example of a fabricated RC bridge.