Location

San Diego, California

Session Start Date

5-24-2010

Session End Date

5-29-2010

Abstract

Multi-storied reinforced concrete frame (RCF) buildings with open first storey to provide parking space is common in Dhaka city, the capital of Bangladesh. Such buildings are likely to produce soft storey action when subjected to earthquake loadings. Bangladesh building code places Dhaka in a moderate earthquake zone with a zone coefficient (Z) value of 0.15. Several soft soil sites exist in the city, most of which have been created by filling up of low lands and water bodies without proper compaction. Such soft soil sites are likely to produce major site amplification effects during earthquakes. One-dimensional wave propagation using the computer program SHAKE is used for selected soft soil profile of Dhaka. In the absence of measured shear wave velocity data, empirical relations are used to obtain shear wave velocity from Standard Penetration Test (SPT) data. Ground motion time histories are obtained for different input motions. Due to the absence of strong motion records for Dhaka city, US and Japanese strong motion records for four different earthquakes were used as input (outcrop) motion. Two-dimensional finite element models of six and ten storied RCF buildings with and without infill walls in the ground floor are subjected to the ground motion obtained for the specific site. Infill wall action is approximated with equivalent strut action. Elastic transient time history analysis is conducted using the computer program ETABS. To account for the energy dissipation in the structural elements due to inelastic action during strong earthquakes, the seismic response obtained is divided by a factor equal to the reduction factor R specified in the building code. Results thus obtained are compared to demonstrate the significant effect of soft soil site on the seismic response of buildings with soft storey.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

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

Meeting Name

Fifth Conference

Publisher

Missouri University of Science and Technology

Publication Date

5-24-2010

Document Version

Final Version

Rights

© 2010 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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May 24th, 12:00 AM May 29th, 12:00 AM

Soft Soil Effect on Soft Storey Response

San Diego, California

Multi-storied reinforced concrete frame (RCF) buildings with open first storey to provide parking space is common in Dhaka city, the capital of Bangladesh. Such buildings are likely to produce soft storey action when subjected to earthquake loadings. Bangladesh building code places Dhaka in a moderate earthquake zone with a zone coefficient (Z) value of 0.15. Several soft soil sites exist in the city, most of which have been created by filling up of low lands and water bodies without proper compaction. Such soft soil sites are likely to produce major site amplification effects during earthquakes. One-dimensional wave propagation using the computer program SHAKE is used for selected soft soil profile of Dhaka. In the absence of measured shear wave velocity data, empirical relations are used to obtain shear wave velocity from Standard Penetration Test (SPT) data. Ground motion time histories are obtained for different input motions. Due to the absence of strong motion records for Dhaka city, US and Japanese strong motion records for four different earthquakes were used as input (outcrop) motion. Two-dimensional finite element models of six and ten storied RCF buildings with and without infill walls in the ground floor are subjected to the ground motion obtained for the specific site. Infill wall action is approximated with equivalent strut action. Elastic transient time history analysis is conducted using the computer program ETABS. To account for the energy dissipation in the structural elements due to inelastic action during strong earthquakes, the seismic response obtained is divided by a factor equal to the reduction factor R specified in the building code. Results thus obtained are compared to demonstrate the significant effect of soft soil site on the seismic response of buildings with soft storey.