Pounding Effects in Simply Supported Bridges Accounting for Spatial Variability of Ground Motion: A Case Study

Abstract

This study carries out a parametrical analysis of the seismic response to asynchronous earthquake ground motion of a long multispan rc bridge, the Fener bridge, located on a high seismicity area in the north-east of Italy. A parametrical analysis has been performed investigating the influence of the seismic input correlation level on the structural response: a series of nonlinear time history analyses have been executed, in which the variation of the frequency content in the accelerograms at the pier bases has been described by considering the power spectral density function (PSD) and the coherency function (CF). In order to include the effects due to the main nonlinear behaviours of the bridge components, a 3D finite element model has been developed, in which the pounding of decks at cap-beams, the friction of beams at bearings, and the hysteretic behaviour of piers have been accounted for. The sensitivity analysis has shown that the asynchronism of ground motion greatly influences pounding forces and deck-pier differential displacements, and these effects have to be accurately taken into account for the design and the vulnerability assessment of long multispan simply supported bridges.

Pounding Between Superstructure Segments in Multi-Supported Elevated Bridge with Three-Span Continuous Deck Under 3D Non-Uniform Earthquake Excitation

“…The 3D pounding analysis between deck elements, as well as between deck and abutment, was carried out by Bi and Hao [2011]. Tecchio et al [2012] studied pounding effects in simply supported bridges accounting for spatial variability of ground motion. The detailed numerical analysis of pounding-involved response of a bridge at a canyon site to spatially varying ground motions was also conducted by Bi et al [2013].…”

“…Most of the analyses were focused on bridge systems with simply supported deck elements (see, for example, Zanardo et al [2002], Bi and Hao [2011] and Tecchio et al [2012]) and the investigations for bridges with multi-span continuous deck under multi-component spatially varying ground motions have not been carried out so far. Moreover, a number of researchers used relatively simple lumped-mass models in their studies [Jankowski et al, 1998;Ruangrassamee and Kawashima, 2001;Muthukumar, 2002, 2004;Hao, 2005, 2008].…”

“…Moreover, a number of researchers used relatively simple lumped-mass models in their studies [Jankowski et al, 1998;Ruangrassamee and Kawashima, 2001;Muthukumar, 2002, 2004;Hao, 2005, 2008]. Also, the non-uniformity of ground motion was defined by only the wave passage effect [Jankowski et al, 1998 or by the wave passage and incoherence effects [Zanardo et al, 2002;Tecchio et al, 2012] without considering the site response effect. In the case of some analyses, the earthquake excitation was applied only in one, longitudinal direction of the bridge (see, for example, DesRoches and Muthukumar [2004]) rather than in all three directions simultaneously.…”

“…Moreover, modeling of bridge bearings was often simplified by using a linear model Bi and Hao, 2011] or a bilinear one [Zanardo et al, 2002]. Some simplifications were also incorporated in the models of structural interactions, for example, by considering gap elements acting only in the longitudinal direction [Zanardo et al, 2002;DesRoches and Muthukumar, 2004;Tecchio et al, 2012].…”

A Structural Pounding Formulation Using Systematic Modal Truncation

“…[1,3,8,[22][23][24]). Mostly pounding elements with a linear or a nonlinear spring damper system, following the Hertz law, are applied (cf.…”