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Extracting the building response using seismic interferometry: Theory and application to the Millikan Library in Pasadena, California

Bulletin of the Seismological Society of America

By:
and
DOI: 10.1785/0120050109

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Abstract

The motion of a building depends on the excitation, the coupling of the building to the ground, and the mechanical properties of the building. We separate the building response from the excitation and the ground coupling by deconvolving the motion recorded at different levels in the building and apply this to recordings of the motion in the Robert A. Millikan Library in Pasadena, California. This deconvolution allows for the separation of instrinsic attenuation and radiation damping. The waveforms obtained from deconvolution with the motion in the top floor show a superposition of one upgoing and one downgoing wave. The waveforms obtained by deconvolution with the motion in the basement can be formulated either as a sum of upgoing and downgoing waves, or as a sum over normal modes. Because these deconvolved waves for late time have a monochromatic character, they are most easily analyzed with normal-mode theory. For this building we estimate a shear velocity c = 322 m/sec and a quality factor Q = 20. These values explain both the propagating waves and the normal modes.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Extracting the building response using seismic interferometry: Theory and application to the Millikan Library in Pasadena, California
Series title:
Bulletin of the Seismological Society of America
DOI:
10.1785/0120050109
Volume
96
Issue:
2
Year Published:
2006
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Bulletin of the Seismological Society of America
First page:
586
Last page:
598