Vertical Component of Ground Motion – Is It Important?

Synopsis

Site response analysis is commonly performed to account for local site effects on ground motion propagation during an earthquake. Most site response analyses involve horizontal ground motion, considering vertically propagating shear waves in horizontally layered systems. In reality, the ground is simultaneously subjected to shaking in both the horizontal and vertical directions during an earthquake, but the vertical response has received limited attention in the literature. Field evidence from various recent earthquakes indicates that damage of concrete buildings and bridges can be attributed to high vertical ground motion, while the vertical component is also important for the design of critical facilities such as nuclear power plants and offshore wind turbines.

The talk will first give an overview of fundamental aspects of vertical site response analysis, demonstrating the impact of parameters characterising the hydraulic phase, i.e. soil permeability and pore fluid compressibility, on vertical site response predictions in terms of both frequency content and amplification. A practical methodology will be presented which allows the direct use of existing site response software, originally developed for propagation of shear waves, to perform site response analysis for vertical ground motion. Finally, the impact of the vertical component of ground motion will be demonstrated in three-dimensional analyses for a KiK-net down-hole array in Japan, comparing the numerical predictions against field measurements.

About the speaker

Dr Stavroula Kontoe is a Senior Lecturer in Geotechnics, specialising in the development and application of numerical methods for geotechnical structures under seismic and dynamic loading. She holds a degree in Civil Engineering from the National Technical University of Athens (2001), an MSc in Soil Mechanics and Engineering Seismology (2002) and a PhD in Computational Geomechanics (2006) from Imperial College London (ICL). Dr Kontoe has led a large number of research projects on the seismic performance of tunnels, retaining structures and dams, on site response analysis and its incorporation in seismic hazard studies, topographic effects on seismic ground motion, soil liquefaction, modelling vibrations induced by pile driving and slope stability in strain softening materials. Her publication record includes 35 journal and more than 40 conferences papers. She won the 2008 BGA Medal, the 2012 Computers & Geotechnics outstanding reviewer award and the 2017 Prakash Foundation Excellence in Teaching prize. She sits on the editorial board of Computers & Geotechnics, has served on the Geotechnique Advisory Panel (2013-2015), represents the UK in Technical Committee TC203 of ISSMGE and in the European and International Associations of Earthquake Engineering. She is an elected committee member of the Society for Earthquake and Civil Engineering Dynamics since 2008.

Further information

This evening meeting is organised by SECED and chaired by Paul Doyle (Jacobs). 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 5.30pm - 6.00pm. 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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Event Details

Event Date 30/05/2018 6:00 pm
Location
Institution of Civil Engineers
1 Great George Street Westminster, London SW1P 3AA United Kingdom
Institution of Civil Engineers

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