A DISPLACEMENT BASED PREDICTION OF THE SEISMIC HAZARD FOR AUSTRALIA N. LAM, J. WILSON, M. EDWARDS AND G. HUTCHINSON THE UNIVERSITY OF MELBOURNE AUTHORS: Nelson Lam is a Research Fellow at The University of Melbourne. He has 16 years of structural engineering experience. He was Chartered Engineer with Scott Wilson Kirkpatrick & Partners until 1989 when he began his academic career at The University of Melbourne specialising in the field of earthquake engineering. He has produced numerous publications in many different areas of earthquake engineering. John Wilson is Chairman of the Board of Engineering, Victorian Division of the Institution of Engineers, Treasurer of the Australian Earthquake Engineering Society, and Member of the Australian Standards Committee for Earthquake Loading. He was Senior Engineer with Ove Amp and Partners before becoming Senior Lecturer at The University of Melbourne in 1992. He is co-author of a book and numerous publications in many different areas of earthquake engineering and structural dynamics. Mark Edwards is a member of both the Australian Earthquake Engineering Society and the New Zealand National Society for Earthquake Engineering. He has had four years geotechnical and ten years structural engineering experience with an on-going interest in earthquake engineering and its applications. He is currently carrying out research on the displacement based method at the University of Melbourne. He has authored and co-authored a number of publications in the earthquake engineering area. Graham Hutchinson is Professor and Head of the Department of Civil and Environmental Engineering at The University of Melbourne. He is President of the Australian Earthquake Engineering Society, and a past Chairman of the Victorian Division of the Institution of Engineers, Australia. He has written two books and over 100 papers on earthquake engineering and structural dynamics. He is also specialist consultant for earthquake engineering related projects all over the world. ABSTRACT: The displacement based design procedure has been developed recently for the seismic design and the evaluation of different types of structures. The substitute structure model used in the procedure enables the inelastic displacement to be predicted from the elastic displacement spectra. This paper introduces a new displacement spectrum model for both rock and soil sites. The displacement spectrum model for rock sites takes into account the properties of the earthquake source and the transmission path in accordancewith a seismological model. The displacement spectrum model for the soil sites takes into account the natural period of the site and the frequency properties of the bedrock excitations. Paper No. 20