Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Selecting and Scaling Earthquake Ground Motions for Performing Response-History Analyses



Andrew Whittaker, Gail Atkinson, Jack Baker, Jonathan Bray, Damian Grant, Ronald Hamburger, Curt Haselton, Paul Somerville


The primary objective of this task was to develop guidance for selecting, generating, and scaling earthquake ground motions for effective use in performing response history analyses for use in performance-based seismic engineering. The need for such guidance was identified in the ATC-57 report, The Missing Piece: Improving Seismic Design and Construction Practices (ATC, 2003), which defines a roadmap for the NIST problem-focused research and development program in earthquake engineering. Following a thorough study of the state of the practice with regard to selecting and scaling ground motions for nonlinear response-history analysis of buildings, the project team developed a list of key challenges facing design professionals tasked with selecting and scaling earthquake ground motions. Based on the findings identified, and considering the potential for impacting design practice in the near-term, the following topics were chosen for study: (1) selection of ground motions based on the Conditional Spectrum; (2) response-spectrum matching; and (3) near-fault ground motions and fault-rupture directivity. To encourage consensus and consistency in the state of the practice going forward, recommendations related to selecting and scaling ground motions for design and performance assessment of low- and medium-rise buildings, and a discussion on best practices for applying the current rules in building codes and standards, are provided.
Grant/Contract Reports (NISTGCR) - 11-917-15
Report Number


NEHRP Consultants Joint Venture, ATC, Ground Motions, Spectrum Matching, Conditional Spectrum


Whittaker, A. , Atkinson, G. , Baker, J. , Bray, J. , Grant, D. , Hamburger, R. , Haselton, C. and Somerville, P. (2011), Selecting and Scaling Earthquake Ground Motions for Performing Response-History Analyses, Grant/Contract Reports (NISTGCR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed December 9, 2023)
Created November 15, 2011, Updated February 19, 2017