Seismic performance of irregular bridges – comparison of different nonlinear static procedures

Abstract

The adequate seismic performance of transportation infrastructures is important for the functioning of the economy and society. This paper focuses on the seismic assessment and analysis of one of the most important components of these infrastructures, the bridges. In this field, nonlinear static procedures (NSPs) have gained significant attention, resulting in different proposals to improve the accuracy of the procedures while keeping their simplicity. The main goal of this study is focused on the evaluation of the applicability of NSPs for irregular reinforced concrete viaducts. A comparative approach is pursued by resorting to (1) the analyses of the performance of three well-known NSPs (N2 method, modal pushover analysis and adaptive capacity spectrum method) and (2) the extension of the scope of previous studies in this field to a more recent method, the extended N2. As such, a set of bridges with different levels of irregularity, configurations and lengths is investigated. The accuracy of different NSPs is evaluated by comparing the results of NSPs with the ones obtained by means of nonlinear dynamic analyses. The comparison of results confirms the acceptable performance of the multi-modal NSPs and highlights the effectiveness of extended N2 method with respect to its simplicity.

Parametric Characterization of RC Bridges for Seismic Assessment Purposes

“…Such fragility functions can be determined using deterministic or, more commonly, probabilistic approaches [11]. A number of past studies have addressed the seismic assessment of individual bridge structures through nonlinear static or dynamic analysis [5,14,19,20,28]. However, such research was built upon the knowledge and the applications initially developed for building structures [10,21,27] and it resulted in the proposal of fragility curves for individual structures [7,8,16,24].…”

Shaking table tests for the experimental verification of the effectiveness of an automated modal parameter monitoring system for existing bridges in seismic areas

“…Recognizing the need of developing further knowledge about the structural behavior of structures built according to obsolete design codes or in the absence of any consideration of seismic action, several authors investigated the seismic performance of existing bridges. This assessment has been usually based on nonlinear static or dynamic analyses, and fragility curves for individual structures have been proposed to support the definition of post‐earthquake scenarios. The development of fragility curves for individual bridges in a broad area can be unfeasible because of the associated large computational efforts.…”

Probabilistic Seismic Assessment of RC Bridges: Part I — Uncertainty Models

“…If the latter approach is followed the number of structural analyses will increase but the statistical meaning of the computed failure probability will be higher. The vulnerability function can also be estimated recurring to nonlinear static procedures (based on pushover analysis), whose validity in estimating nonlinear response of bridges (and buildings) has been significantly recognised in recent studies [2,8,19,20,27,35,41,43,44]. The advantages in using such nonlinear static approach would be immediate given that N nonlinear dynamic analyses are replaced by less onerous static analysis.…”