Seismic fragility assessment of geotechnical seismic isolation (GSI) for bridge configuration

Abstract

The seismic vulnerability of bridges may be reduced by the application of Geotechnical Seismic Isolation (GSI) below the foundations of the columns and the abutments. However, the role of GSI on the seismic response of bridges has been limitedly examined in literature. Therefore, this research has been conducted to study the effect of applying GSI on the seismic response of bridges to address the aforementioned gap in knowledge. Advanced nonlinear dynamic three-dimensional finite element analyses have been conducted using OpenSees to study the influence of the GSI. The cases of traditional and isolated bridges subjected to earthquakes have been considered to assess the GSI effects. The results showed that the GSI reduces the seismic effect on the column while its effect seems to be less significant for the abutments. In addition, fragility curves for the traditional and isolated cases have been developed and compared to provide insights with a probabilistic-based approach. The results of this paper provide a useful benchmark for design considerations regarding the use of GSI for bridges.

An Eco-sustainable Innovative Geotechnical Technology for the Structures Seismic Isolation, Investigated by Fem Parametric Analyses

“…In the framework of the mitigation of the seismic risk, Geotechnical Seismic Isolation (GSI) is an innovative low-cost technique for protecting structures in earthquake-prone areas, alternative to traditional seismic isolation systems, such as: elastomeric bearings, sliding elements, and friction-pendulum systems (Kelly 1990;Naeim and Kelly 1999), whose installation and maintenance are considered quite expensive economically and technically for conventional buildings; moreover, these solutions are almost prohibited in developing countries where the financial resources are limited. The main idea of GSI is to improve the foundation soil so that seismic energy will be partially dissipated within GSI before being transmitted to the structure (Tsang 2009;Tsang et al 2012;Mavronicola et al 2010;Pitilakis et al 2015;Pistolas et al 2010;Forcellini and Alzabeebee 2022). Among other materials proposed for foundation soil improvement, gravelrubber mixtures (GRMs) have attracted significant research thanks to their good static and dynamic properties: low specific weight, high elasticity, low shear modulus, and high damping (Anastasiadis et al 2012;Senetakis et al 2012a-b;Senetakis and Anastasiadis 2015;Pistolas et al 2018;Tsiavos et al 2019;Tasalloti et al 2021 a-c).…”

“…GRMs suitability and advantages as GSI in the form of a layer underlying the foundation of structures have been investigated numerically over recent years (Tsang 2009;Tsang et al 2012;Pitilakis et al 2015;Pistolas et al 2010;Forcellini and Alzabeebee 2022;Tsang et al 2019;Dhanya et al 2020;Chiaro et al 2020). On the other hand, only a few experimental studies are available in the literature, mainly limited to laboratory and small-scale testing (Kaneko et al 2013;Xiong and Li 2013;Chiaro et al 2021;Tsang et al 2020;Bandyopadhyay et al 2015;Tsiavos et al 2019;Tasalloti et al 2021a).…”

Analytical Solution for Bearing Capacity of Reinforced Strip Footings on Unsaturated Soils under Steady Flow

“…In addition, Nazeeh and Babu [21] used kriging surrogates to perform a reliability analysis of geogrid-reinforced soil foundations. In addition, some scholars have investigated the application of geotechnical seismic isolation (GSI) to different foundations, some of them using experimental studies [22] and others using finite element analyses [23,24].…”

Analytical design models for geotechnical seismic isolation systems

“…In the past one and a half decades, numerical simulations and analytical modelling have been conducted by various researchers to demonstrate the effectiveness of GSI systems (Tsang et al 2009(Tsang et al , 2012aPitilakis et al 2015;Anbazhagan et al 2015;Abdullah and Hazarika 2016;Brunet et al 2016;Dhanya et al 2020;Forcellini and Alzabeebee 2022). Experimental testing and field measurement have also been performed to confirm the isolation mechanism and to evaluate their performance (Kaneko et al 2013;Nikitas et al 2014;Nappa et al 2016;Tsiavos et al 2019;Tsang et al 2021;Pitilakis et al 2021).…”