cowi and imperial college london closing knowledge gap within marine construction

PRESS RELEASE: A research project between COWI and Imperial College London has won a Research Award from the Institution of Structural Engineers.

19.10.2018

At present, there is very limited research and testing of hollow steel pipe piles, commonly used in marine construction. The research indicates that they may be susceptible to inelastic buckling and low cycle fatigue when subjected to cyclic loading, such as during an earthquake. A reliable and predictable description of the inelastic post buckling behaviour of steel circular hollow sections in the marine pile range in cyclic loading would be indispensable for their performance based seismic design in the marine pile range - however, such a characteristic does not yet exist.

Thanks to a £6000 research award from the Institution of Structural Engineers, the research team are designing an experimental campaign to close the current knowledge gap.

COWI Technical Director, Dimitris Pachakis, with Senior Lecturers Adam Jan Sadowski and Christian Málaga Chuquitaype from Imperial College London, are experimentally and numerically exploring and the ductile behaviour of hollow steel sections in cyclical loading in the inelastic range.

The experimental part will test specimens with slenderness ratios similar to those of marine piles in cyclic bending, aiming to gain understanding on local buckling and low cycle fatigue.

The numerical part aims to model and predict the observed section behaviour with finite elements.

The study is expected to have a significant impact to the structural engineering industry. Not only will it stimulate further research into full scale testing under cyclic loading conditions, but any reliable results will also influence the upcoming update of the 'Standard for the Seismic Design of Piers and Wharves' (ASCE 61-19) of which COWI is a member. This Standard is the de-facto guideline used for seismic design of marine structures worldwide.

The six-month research campaign will begin on February 2019 and results will be disseminated following completion.

Project Team

Dr Dimitris Pachakis, Industry Partner, is a Civil/Structural Engineer, licenced in Greece, California, the UK and UAE, with 20 years of research and working experience in port and earthquake engineering. His doctoral research involved modelling and simulating container terminal operations and estimating the business interruption risk during earthquakes. After graduating with a PhD from Stanford in 2004, he has worked on a wide range of port planning and engineering projects involving medium and large container terminals, liquid and solid bulk terminals, and oil and gas supply bases. His key areas of expertise are maritime structures design and inspection, earthquake structural engineering, container terminal planning, operations analysis and simulation, technical and operational due diligence. He has been member of PIANC MarCom's Working Group 135 - "Design Principles for Container Terminals in small and medium ports", the ASCE61-14 Standards Committee "Seismic Design of Piers and Wharves", and currently the PIANC Working Group 158 "Planning of Greenfield Ports" and the ASCE61-19 Standard Committee tasked with updating ASCE61-14.

Adam Jan Sadowski, Principal Investigator

Dr Sadowski is a Lecturer in Structural Engineering at Imperial College London. He has an extensive research profile working on the simulation of buckling and plastic collapse in metal shells and in cylindrical forms in particular. His research has contributed significantly to the enhancement of EN 1993-1-6, in particular regarding the characterisation of slenderness limits and the slenderness-dependent resistance of cylindrical shells, including circular hollow sections, under bending loads. He has extensive expertise in numerical modelling under both static and dynamic loadings and routinely supervises MEng, MSc and PhD students in the field.

Christian Málaga Chuquitaype, Co-Investigator

Dr Málaga is an Earthquake Engineer currently working as a Senior Lecturer in Structures at Imperial College London. He holds degrees in Earthquake Engineering and Engineering Seismology from the Universities of Pavia, Grenoble, and Imperial College. He is involved in teaching undergraduate and postgraduate courses in structural dynamics and structural timber. His main research interests are related to the response of new and traditional structures to extreme loads. He has extensive expertise in the experimental and numerical assessment of structural components and systems.

About the Research Award

The Research Award is the largest standalone funding opportunity given by the Institution of Structural Engineers and is run every two years. Grants of £6,000 are available, provided by the Institution’s Research Fund, to support collaborative research projects between industry and academia.

The Research Award supports high-quality research into structural engineering and looks for new inventive projects or proposals to develop ongoing research.