Stability of Fiber-Reinforced Bridge Bearings under Compression and Shear Loads

Stability of Fiber-Reinforced Bridge Bearings under Compression and Shear Loads

Abstract: 

Fiber-Reinforced Bearings (FRBs) have proven to be a valuable rubber-based base isolation technology in which flexible fiber reinforcements are used to replace the steel layers commonly adopted for the manufacturing of Laminated Rubber Bearings (LRBs). Thanks to the low weight and cost of FRBs, these devices could prove to be instrumental for the promotion of base isolation applications to houses and residential buildings of developing countries in seismic regions. This report presents the results of a large set of Finite Element Analyses (FEAs) aimed at assessing the performance of FRBs under combined axial and shear loads. The effects of different magnitudes of axial pressure, material properties, and primary and secondary bearing shape factors on the stability of the devices under combined axial and shear loads are discussed in this work. Conclusions of this study underline that the simple design formulae commonly adopted for FRBs underestimate the effect of the axial pressure in limiting the lateral displacement capacity of the bearings. Additional Finite Element Analyses are needed to extend the results of this study to bearings of other shapes, including circular and square isolators.

Authors: 

ANDREA CALABRESE, PHD, ING, CENG, MICE

Dr. Calabrese joined the California State University Long Beach, Civil Engineering and Construction Engineering Management (CECEM) Department as an Assistant Professor in Fall 2017. He gained a PhD in Construction Engineering with an emphasis in Structural Engineering in 2013. He was a visiting research fellow at the Pacific Earthquake Engineering Research Center (PEER) from 2010–2012 along with having been a postdoctoral researcher of the ReLUIS Consortium at the Italian Network of University Laboratories in Earthquake Engineering from 2013–2014. Dr. Calabrese has worked as a Structural Engineer at Foster & Partners (London and Italy) for seven years. He has been a registered engineer in Italy since 2009 and a Chartered Engineer (CEng) and Full Member of the Institution of Civil Engineers (MICE) in the UK since 2017. Dr. Calabrese’s current research interests are in the fields of experimental testing, structural dynamics, base isolation, vibration engineering, and the development of novel low-cost devices for the seismic protection of buildings. He has carried out numerous large-scale experimental studies of base isolation systems and energy-absorbing devices on the shaking table at the Department of Structural Engineering at the University of Naples in Italy. This work has been instrumental in developing low-cost seismic isolation systems using recycled rubber and flexible reinforcements for the seismic protection of buildings in developing regions.

SIMONE GALANO, VISITING SCHOLAR

Simone Galano is a PhD student from the University of Naples Federico II, Italy. He is currently working at the CSULB CECEM Department on a portion of the research studies for his doctoral thesis. His responsibilities included the preparation of the research report.

TRAN NGHIEM, RESEARCH ASSISTANT

Tran Nghiem is an undergraduate student at the CSULB CECEM Department. His responsibilities included performing this study’s Finite Element Analyses.

Published: 

July 2020

Keywords: 

Base isolation
Recycled rubber
Fiber-reinforced bearings
Instability
Finite element analyses