EQTOOLS: Software for Characterization, Evaluation, and Modification of Strong Ground Motions within Performance-Based Seismic Design Framework

Abstract

EQTOOLS is a computer program that has been specifically designed with the objective of providing engineers, researchers, and students with facilitated access to powerful state-of-the-art computational tools in the field of engineering seismology and earthquake engineering within a performance-based design framework. EQTOOLS constitutes an easy and efficient way to process strong -motion data, featuring a user-friendly visual interface and the capability to derive a number of strong-motion parameters often required by structural engineers, s eismologists, and geotechnical earthquake engineers. In addition to this, EQTOOLS also provides the necessary means to investigate frequency content of accelerograms, carry out high pass, low-pass, band-pass, and band-stop filtering using three different digital filter types, generate and scale elastic response spectra, and perform time -domain linear or nonlinear site response analysis. While EQTOOLS may be used for professional practice or academic research, the fundamental purpose behind the development of the software was to make available a classroom/laboratory tool that provides a visual basis for learning the principles behind the selection of ground motion histories and their scaling/modification for input into time domain nonlinear (or linear) analy sis of structures. This paper describes the basic features of EQTOOLS, and provides suggestions for its application in a learning environment. The latest version of EQTOOLS may be obtained at no cost by sending an e -mail to the authors of this paper. Programming Philosophy EQTOOLS was developed using Microsoft’s Visual Basic 6.0, Enterprise Edition. All the input in the EQTOOLS environment is carried out interactively through the use of the computer keyboard and the mouse. The application i s graphics-intensive and every effort has been made to make it as user -friendly as possible. For the current version, plots generated using the computational tools in the EQTOOLS environment are displayed on the screen in seve ral different “windows” and tabular output information can be saved in tab-delimited Microsoft Excel format. This feature allows the user to perform further processing of the data or to graph the output data for inclusion in reports and other documents. H ard copies of any of the screen plot windows may be obtained.