This paper presents a study on the seismic response trends evaluation and finite element model updating of a reinforced concrete building monitored for a period of more than two years. The three story reinforced concrete building is instrumented with five tri-axial accelerometers and a free-field tri-axial accelerometer. The time domain N4SID system identification technique was used to obtain the frequencies and damping ratios considering flexible base models taking into account the soil-structure-interaction using 50 earthquakes. Trends of variation of seismic response were developed by correlating the peak response acceleration at the roof level with identified frequencies and damping ratios. A general trend of decreasing frequencies was observed with increased level of shaking. To simulate the varying behavior of the building with response levels, a series of three dimensional finite element models were calibrated considering several points on the developed frequency-response amplitude trend lines as targets for updating. To incorporate real in-situ conditions, soil underneath the foundation and around the building was modeled using spring elements and nonstructural components (claddings and partitions) were also included. Sensitivity based model updating technique was applied taking into account concrete, soil and cladding stiffness as updating parameters. It was concluded from the investigation that knowledge of the variation of seismic response of buildings is necessary to better understand their behavior during earthquakes, and also that the participation of soil and non-structural components is significant towards the seismic response of the building and these should be considered in models to simulate the real behavior.
|Title of host publication||Proceedings SPIE 8694|
|Subtitle of host publication||Nondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security 2013|
|Editors||Tzu Yang Yu, Andrew L. Gyekenyesi, Peter J. Shull, Aaron A. Diaz, H. Felix Wu, A. Emin Aktan|
|Number of pages||13|
|Publication status||Published - 16 Apr 2013|
|Event||SPIE 20th Annual International Symposium on Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring - Town & Country Resort and Convention Center, San Diego, United States|
Duration: 10 Mar 2013 → 14 Mar 2013
|Conference||SPIE 20th Annual International Symposium on Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring|
|Period||10/03/13 → 14/03/13|
The authors would like to thank their supporters. GeoNet staff, particularly Dr Jim Cousins, Dr S.R. Uma and Dr Ken Gledhill, helped with access to seismic data and building information. Faheem Butt’s PhD study was funded by Higher Education Commission (HEC) Pakistan. Piotr Omenzetter’s work within The LRF Centre for Safety and Reliability Engineering at the University of Aberdeen is supported by The Lloyd's Register Foundation (The LRF). The LRF supports the advancement of engineering-related education, and funds research and development that enhances safety of life at sea, on land and in the air.
- Instrumented RC building
- structural health monitoring
- seismic response
- system identification
- model updating