Seismic vulnerability assessment of precast post-tensioned segmental bridge piers subject to far-fault ground motions

Abstract Relationships between seismic action, system response and relevant damage levels in industrial plants require a solid background both in experimental data, due to the high level of non-linearity and seismic input. Besides, risk and fragility analyses depend on the adoption of a huge number of seismic records usually not available in a site-specific analysis. In order to manage these issues and to gain knowledge on the definition of damage levels, limit states and performance for major-hazard industrial plant components, we present a possible approach for an experimental campaign based on a real prototype industrial steel structure. The investigation of the seismic behaviour of the reference structure will be carried out through shaking table tests. In particular, tests are focused on structural or process-related interactions that can lead to serious secondary damages as leakage in piping systems or connections with tanks and cabinets. The aforementioned test program has been possible thanks to the adoption of: i) a number of artificial spectrum-compatible accelerograms; ii) a ground motion model (GMM) able to generate a suite of synthetic time-histories records for specified site characteristic and earthquake scenarios. More precisely, GMM model parameters can be identified by matching the statistics of a target-recorded accelerogram to the ones of the model in terms of faulting mechanism, earthquake magnitude, source-to-site distance and site shear-wave velocity. As a result, the stochastic model, based both on these matched parameters and on filtered white-noise process, can generate the ensemble of synthetic ground motions capable of capturing the main features of real earthquake ground motions, including intensity, duration, spectral content and peak values. Moreover, the synthetic records are selected to target specific damages and limit states in industrial components. Finally, by means of the combination of artificial and synthetic accelerograms, a seismic vulnerability assessment of both the whole structure and relevant industrial components can be carried out.

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Seismic Vulnerability Assessment of a Multi-Span Continuous Highway Bridge Fitted with Shape Memory Alloy Bars and Laminated Rubber Bearings

Earthquake Spectra ◽

10.1193/1.4000089 ◽

2012 ◽

Vol 28 (4) ◽

pp. 1379-1404 ◽

Cited By ~ 30

Author(s):

M. A. Rahman Bhuiyan ◽

M. Shahria Alam

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Vulnerability Assessment ◽

Seismic Vulnerability ◽

Longitudinal Direction ◽

Bridge Piers ◽

Highway Bridge ◽

Seismic Vulnerability Assessment ◽

Rubber Bearings ◽

Bridge System

This study performs seismic vulnerability assessment in the longitudinal direction of a three-span continuous highway bridge, restrained by shape memory alloy (SMA) bars and isolated with laminated rubber bearings. The analytical simulation method based on incremental dynamic analyses is used in evaluating the seismic fragility functions of the bridge components (pier and isolation bearing) and the system. A two-dimensional finite element model scheme with nonlinear force-displacement relationships is used for the bridge piers and bearings. This study shows that the bridge piers with SMA bars have led to relatively higher seismic vulnerability over the bridge piers without SMA bars, which is also reflected in the bridge system. The isolation bearings with SMA bars have revealed comparatively less seismic vulnerability than those without SMA bars. From the numerical results, it is recognized that the failure probability of the bridge system is dictated by the bridge pier over the isolation bearing.

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