U.S. Geological Survey Open-File Report 2010-1068
Earthquake engineering practice is increasingly using nonlinear response history analysis (RHA) to demonstrate performance of structures. This rigorous method of analysis requires selection and scaling of ground motions appropriate to design hazard levels. Presented herein is a modal-pushover-based scaling (MPS) method to scale ground motions for use in nonlinear RHA of buildings and bridges. In the MPS method, the ground motions are scaled to match (to a specified tolerance) a target value of the inelastic deformation of the first-“mode” inelastic single-degree-of-freedom (SDF) system whose properties are determined by first-“mode” pushover analysis. Appropriate for first-“mode” dominated structures, this approach is extended for structures with significant contributions of higher modes by considering elastic deformation of second-“mode” SDF system in selecting a subset of the scaled ground motions. Based on results presented for two bridges, covering single- and multi-span “ordinary standard” bridge types, and six buildings, covering low-, mid-, and tall building types in California, the accuracy and efficiency of the MPS procedure are established and its superiority over the ASCE/SEI 7-05 scaling procedure is demonstrated.
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Kalkan, E., and Chopra, A.K., 2010, Practical guidelines to select and scale earthquake records for nonlinear response history analysis of structures: U.S. Geological Survey Open-File Report 2010-1068, 124 p.
2. Modal-Pushover-Based Scaling
3. Code-Based Scaling Procedure
4. Ground Motion Selection Procedure
5. Evaluation of MPS Procedure: Low- and Mid-Rise Buildings
6. Evaluation of MPS Procedure: Tall Buildings
7. Evaluation of MPS Procedure: Short-Period Building
8. Evaluation of MPS Procedure: “Ordinary Standard” Bridges
9. Summary and Conclusions
10. References Cited
12. Appendix A: Computation of Minimum Scale Factor