Location

St. Louis, Missouri

Session Start Date

3-11-1991

Session End Date

3-15-1991

Abstract

In a recent compilation and analysis of nearly 750 accelerograms, we studied six pairs of triaxial accelerograms recorded digitally at two neighboring sites underlain by rock and soil, respectively. The distance between the two sites, both located south of the SMART1 array in northeast Taiwan, is approximately 2 km. The epicentral distances are less than 80 km. For each component, we computed the ratios of peak and spectral amplitudes recorded at the soil site to that of the rock site, for three peak parameters and 23 spectral ordinates. The mean estimates of the soil amplification for the peak parameters range between 1 and 3. The spectral variation of soil amplification factor is similar for the two horizontal components. They are relatively flat in the high frequency range, peak in mid-frequency range, and decrease at longer periods. The N-S component has a ratio of about 1.35 at high frequencies, increasing to about 3 between 1 and 2 seconds, then decreasing to around 2.4 at longer periods. The E-W component shows higher ratios, stating at about 2 at high frequencies, increasing as high as 7 near two sec Period, and falling off to about 2 at longer periods. For the vertical component the soil-to-rock amplitude-ratio is nearly 1.5 in the high frequency range above 2Hz. This ratio increases to nearly 3 in mid-frequency range, and falls off to about unity for longer periods. While the horizontal ratios peak at about 2 sec, the maximum vertical spectral ratio occurs near 0.8 sec.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Meeting Name

Second Conference

Publisher

University of Missouri--Rolla

Publication Date

3-11-1991

Document Version

Final Version

Rights

© 1991 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Mar 11th, 12:00 AM Mar 15th, 12:00 AM

Evaluation of Soil Amplification at Smart1 Array, Taiwan

St. Louis, Missouri

In a recent compilation and analysis of nearly 750 accelerograms, we studied six pairs of triaxial accelerograms recorded digitally at two neighboring sites underlain by rock and soil, respectively. The distance between the two sites, both located south of the SMART1 array in northeast Taiwan, is approximately 2 km. The epicentral distances are less than 80 km. For each component, we computed the ratios of peak and spectral amplitudes recorded at the soil site to that of the rock site, for three peak parameters and 23 spectral ordinates. The mean estimates of the soil amplification for the peak parameters range between 1 and 3. The spectral variation of soil amplification factor is similar for the two horizontal components. They are relatively flat in the high frequency range, peak in mid-frequency range, and decrease at longer periods. The N-S component has a ratio of about 1.35 at high frequencies, increasing to about 3 between 1 and 2 seconds, then decreasing to around 2.4 at longer periods. The E-W component shows higher ratios, stating at about 2 at high frequencies, increasing as high as 7 near two sec Period, and falling off to about 2 at longer periods. For the vertical component the soil-to-rock amplitude-ratio is nearly 1.5 in the high frequency range above 2Hz. This ratio increases to nearly 3 in mid-frequency range, and falls off to about unity for longer periods. While the horizontal ratios peak at about 2 sec, the maximum vertical spectral ratio occurs near 0.8 sec.