An online open-source application for ground motion selection using the GCIM method

Abstract

This paper illustrates two online and freely available applications which can be used for ground motion selection. Ground motions are selected using the generalized conditional intensity measure (GCIM) method (Bradley 2010a, Bradley 2012c), which enables ground motion selection to be based on any general set of ground motion intensity measures, e.g. spectral ordinates, peak ground acceleration/velocity, significant duration, arias intensity, cumulative velocity, etc. Users can firstly perform seismic hazard analysis using OpenSHA (Field, et al. 2003), or their own prototype codes to obtain the ‘target’ GCIM distributions for ground motion selection (Bradley 2010b). Secondly, the OpenSHA output file can be uploaded to the ground motion selection application. The application is written in Javascript, with the source code on GitHub, and allows easy visualization of the intensity measure properties of the selected ground motion ensemble, as well as various diagnostic tests to ensure the selected ensemble is representative of the problem considered. It is emphasised that the use of such online and open-source software is critical to ensure an efficient uptake of novel methodologies in seismic performance assessment.