Design of Integral Bridges to Earthquake Loads: Challenges and Opportunities

Synopsis

Maintenance of infrastructure, including bridges, is a pressing global challenge that drains trillions of investment worldwide. Integral abutment bridges (IABs) are jointless structures without bearings or expansion joints, which require minimum maintenance, hence offering significant cost savings to Highways and Railway Agencies. The popularity of IABs is the result of their advantages over their counterparts, i.e. the jointed bridges. Superior durability, noise reduction, structural redundancy and elimination of the risk of unseating and aesthetic possibilities are some of the advantages of IABs. However, integral bridges are not currently covered by Eurocodes. Hence, amongst other mandates of the Eurocode Committees, IABs have gained significant attention in an effort to encourage practitioners to design IABs. In the UK, where almost 70 % of the bridges are integral, new design guidelines are available, which however limit their length and the skewness. The main reason behind these limitations is the complicated soil-structure interaction (SSI) effects due to abutment movements. As a result of these SSI effects, excessive backfill settlements, abutment failures and variation of stresses within the prestressed deck have been recorded by numerous studies. IAB designs become even more challenging when seismic actions and/or other hazards must be considered. Hence, knowledge gaps exist in the understanding and design of IABs, whilst no framework exists for the risk assessment of IABs subjected to earthquakes or multiple hazards.

This evening meeting will present published research to enable a better understanding of the response of integral abutment bridges under thermal loads, earthquake excitations and excessive floods that cause scouring of the foundations. Advanced numerical modelling will be presented on the basis of realistic models of the structure and the soil. Current modelling techniques will be assessed on the basis of accuracy, including basic modelling assumptions for the foundations and the abutment and oversimplifications related to the stiffness and/or the damping of IABs. The meeting will continue with the presentation of smart designs for IABs with recycled materials as a means to minimise the soil-structure interaction effects for delivering longer IABs and/or having large skewness. The presentation will conclude with recent findings on the multi-hazard risk assessment of IABs and in particular the sequential occurrence of flooding and seismic effects on the vulnerability analysis of representative highway and railway IABs. Future research and design opportunities will be discussed on the basis of the ongoing research.

About the speaker

Dr Stergios Mitoulis graduated with a 5-year Diploma from Aristotle University of Thessaloniki, Greece. He subsequently received an MSc in Earthquake Resistant Structures and a PhD in 2008 from the same University. He is the leader of the Bridge Engineering Research Group (BERG @ www.mitoulis.com). He has published extensively with a publication record exceeding 80 papers in leading scientific journals, international conferences and books. His expertise is the design of transportation infrastructure assets and in particular bridges subjected to extreme and dynamic loads. He is a member of the BSI B/525/10 CEN/TC 250/HG Bridges, the BSI Mirror Group of Eurocode and UK delegate of the BSI (CEN/TC 250/SC8 Work Group 6, Bridges) for the design and retrofit of bridges, the BSI committee B/525/8 and B/538/5 and the Workgroup 11 of the EAEE. He has worked extensively on consulting and research projects on the design and retrofit of precast and prestressed structures, whilst his main teaching activity focuses on the analysis, design and retrofitting of bridges. He has been the Principal Investigator (PI) of KTP (Innovate UK) projects with Network Rail-UK on the monitoring of environmental hazards on infrastructure. He also supervises a H2020 project on the vulnerability of transportation systems of assets exposed to geo-hazards. He has worked as Co-PI and researcher for another 11 research projects. He has editorial and reviewing responsibilities for more than 25 journals. He has served as expert and reviewer for the EPSRC and Horizon 2020. He is an active consultant for industries in the UK and Belgium. He delivers lectures and seminars at consultancies and he also delivers CPD seminars as an official lecturer of the Institution of Civil Engineers.

Further information

This evening meeting is organised by SECED and chaired by Prof. Tiziana Rossetto (UCL). Non-members of the society are welcome to attend. Attendance at this meeting is free. Seats are allocated on a first come, first served basis. Tea, coffee and biscuits will be served from 6pm - 6.30pm. For further information, please contact Shelly-Ann Russell (tel. 020 7665 2147, email This email address is being protected from spambots. You need JavaScript enabled to view it.).

This event will be broadcast online.

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