Framework for Seismic Risk Analysis of Engineering Structures Considering the Coupling Damage from Multienvironmental Factors

Abstract

Many structures service in complex environments where multiple environmental factors (MEFs) coexist, and the coupling effects of MEFs often aggravate structural damage, thus increasing the risk of structural collapse and economic loss under seismic excitation. For structural damage caused by coupling effects of MEFs, previous studies have been mostly focused on one-way coupling analysis, such as the effect of structural pre-corrosion on its fatigue damage, and less attention to the interaction coupling effect of MEFs, which make it difficult to quantitatively calculate the interactive coupling damage due to the existence of MEFs. The large error of using one-way coupling damage calculation method to estimate the residual mechanical performance of the structure will reduce the reliability of seismic risk assessment of the structures suffering interaction coupling of MEFs. To solve such problem, this paper proposes a damage calculation method for structures considering the effect of interaction coupling of MEFs by establishing a multivariable interaction model, in which a coefficient β(t) is introduced to characterize the time-varying mechanisms of the interaction coupling effect of MEFs (e.g., the acceleration of structural damage with service time). Then, the solution method for β(t) is proposed by using Bayesian inference. Finally, a framework for analyzing the time-varying seismic risk of engineering structures considering the evolution of damage caused by interaction coupling of MEFs is established in which the uncertainty of environmental factors is also involved. The presented analysis framework is illustrated using a towering structure in a coastal area, and the results emphasize that the interactive coupling effect of MEFs can significantly increase the risk of structural collapse and economic loss.