Simplified Dispersion Curves of Earthquake Love Wave for Rotational Seismic Motion Estimation

Abstract:

In the simulation of the rotational seismic ground motion, the apparent velocity of Love wave is always assumed to be equal to the S wave velocity of top layer of the site approximately, with the dispersion of surface wave not being fully considered. In this paper, the effect of the velocity structure to the Love wave dispersion is discussed based on the stiffness matrix theory. It shows that to assume the velocity to be equal to the S wave velocity of the top layer may greatly overestimate the low frequency rotational seismic motion. A simplified dispersion curve, is suggested for rotational seismic ground motion simulation. The shape of the bilinear curve is shaped by 3 parameters. They are the corner frequency, the minimum phase velocity and the velocity ratio. The parameters are affected by the velocity structure of the site.

• Periodical: Applied Mechanics and Materials (Volumes 580-583)
• Pages: 1639-1644
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.580-583.1639
• Online since: July 2014
• Authors: Yue Wei Liu, Hong Nan Li
• Keywords: Dispersion, Love Wave, Phase Velocity, Rotational Motion, Simplified Dispersion Curve, Stiffness Matrix

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