用于桥梁时变可靠度分析的承载力衰减新模型（英文）

A realistic resistance deterioration model for time-dependent reliability analysis of aging bridges

目的:提出能够反映劣化桥梁承载力的非增特性以及自相关性的承载力衰减新模型,并利用该模型进行结构可靠度分析。创新点:提出描述劣化桥梁承载力衰减的新的随机过程模型,给出利用实测数据进行模型参数拟合的方法,并利用提出的衰减模型对劣化桥梁进行时变可靠度分析。方法:采用Gamma过程描述承载力衰减的随机过程(公式7),并基于Monte Carlo模拟的方法研究承载力衰减过程的自相关性对可靠度结果的影响。如果将承载力衰减过程假定为完全相关的过程,则会低估结构的失效概率。

Bridge resistance and reliability may deteriorate with time due to aggressive environmental conditions and increasing road freight volumes, resulting in an increase of potential economic loss. This is thus a great concern to decision-makers managing the bridges＇ continued future service. Reasonable models of bridge resistance and applied loads are the fundamentals of accurate estimation/prediction of a bridge＇s serviceability. In this paper, a new model for resistance deterioration is proposed, which enables the non-increasing property and auto-correlation in the stochastic deterioration process to be incorporated. To facilitate the practical application of the model,methods to determine its parameters using obtained data on structural resistance are developed and illustrated through simple numerical examples. Time-dependent reliability analysis is conducted using the proposed resistance deterioration model based on Monte Carlo simulation, and the effect of auto-correlation in the deterioration process on structural time-dependent reliability is investigated.