Open-File Report 2015–1116
Site coefficients corresponding to those in tables 11.4–1 and 11.4–2 of Minimum Design Loads for Buildings and Other Structures published by the American Society of Civil Engineers (Standard ASCE/SEI 7-10) are derived from four of the Next Generation Attenuation West2 (NGA-W2) Ground-Motion Prediction Equations (GMPEs). The resulting coefficients are compared with those derived by other researchers and those derived from the NGA-West1 database. The derivation of the NGA-W2 average site coefficients provides a simple procedure to update site coefficients with each update in the Maximum Considered Earthquake Response MCER maps. The simple procedure yields average site coefficients consistent with those derived for site-specific design purposes. The NGA-W2 GMPEs provide simple scale factors to reduce conservatism in current simplified design procedures.
First posted June 16, 2015, updated June 25, 2015
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Borcherdt, R.D., 2015, NGA-West2 GMPE average site coefficients for use in earthquake-resistant design (ver. 1.1, June 25, 2015): U.S. Geological Survey Open-File Report 2015–1116, 27 p., https://dx.doi.org/10.3133/ofr20151116.
ISSN 2331-1258 (online)
NGA-West2 GMPE Average Site Coefficients for Use in Earthquake-Resistant Design
NGA-West2 Site Coefficients
NGA-W2 Amplification as a Function of Period
Comparison of NGA-W2 and NGA-W1 Amplification Factors with NEHRP Coefficients
NGA-W2 Scaling Factors to Reduce Conservatism in Design Spectra and to Scale Site Amplification Coefficients to Other Reference Site Conditions
Implications of NGA-W2 for ASCE 7-10 (NEHRP) Site Coefficients
Comparison of NGA-W2 Coefficients with Those Proposed for ASCE 7-16