Evaluation of Ground Motion Selection and Modification Methods: Predicting Median Interstory Drift Response of Buildings. PEER Ground Motion Selection and Modification Working Group

摘要

Nonlinear dynamic analysis of structures is becoming increasingly prevalent in code and regulatory documents prescribing design and analysis. A recurring challenge for both practicing engineers and developers of such documents is the selection and modification of ground motions for these nonlinear dynamic analyses. Nonlinear structural response is often highly sensitive to the selection and modification of input ground motions, and many ground motion selection and modification (GMSM) methods have been proposed. No systematic studies exist that provide impartial guidance to engineers regarding appropriate methods for use in a specific analysis application; thus engineers are left to make an important decision that is virtually uninformed. The purpose of this report is to provide the engineering community with a foundation, backed by comprehensive research, for choosing appropriate ground motion selection and modification methods for predicting the median drift response of buildings. To this end, the approach taken in this report is (a) to select and scale ground motions using a wide variety of proposed methods, (b) to use these ground motions as inputs to nonlinear dynamic structural analyses, and then (c) to study differences in the resulting structural response predictions in order to identify what GMSM decisions are most crucial. By studying a large number of GMSM methods and analyzing a variety of structures, this report quantitatively compares many of the GMSM methods available to the engineering community. This report presents the methodology developed by the GMSM Program and the results obtained using 14 ground motion selection and modification techniques (25 if variations of those 14 are considered separately) to analyze four reinforced concrete frame and wall buildings.