Seismic Aggravation in Shallow Basins in Addition to One-dimensional Site Amplification

ABSTRACT

We first classify various basin effects, as the result of sequential combinations of basic wave phenomena, into wedge effects, lens effects, and surface-wave related effects. We then investigate their contributions to the basin aggravation. Our results show that, in a shallow basin, current 1D-based approaches to assess site effects can significantly underestimate the seismic hazard in its close-to-edge region inside the basin at spectral periods below the fundamental period of the soil column at the deepest portion of the basin. In contrast, for a deep basin, ground motions across the whole-width could be underestimated using 1D approaches.

KEYWORDS:

• Basin Effects
• Aggravation Factor
• Site Effects
• Amplification
• Seismic Hazard
• Earthquake

Acknowledgments

The authors thank the Pacific Earthquake Engineering Research (PEER) Centre for providing the strong ground motion recordings, and Prof. Chávez-García F.J. (National Autonomous University of Mexico, Mexico) for his review on this research, as well as Prof. Bard P.Y. (IFSTTAR and University Joseph Fourier-Grenoble, France) for his discussions with the first author on the 2D resonance. Some revisions were made while the first author was on a research visit to the Karlsruhe Institute of Technology, Germany, and hosted by Prof. Joachim Ritter. Thus, the first author thanks, Prof. Joachim Ritter for his suggestions on this manuscript. We thank two reviewers’ comments and suggestion of our manuscript.

Additional information

Funding

The first author is sponsored by the China Scholarship Council (CSC) and the Queensland University of Technology (QUT), Australia, and would like to acknowledge their support for this research.