Ambient Vibration Tests and Model Updating of the Health Sciences Parkade at UBC ILARIA CAPRARO Supervisor: Dr. Carlos E. Ventura MASc | University of Bologna, Italy (2012) PhD Student | The University of British Columbia, Canada (2014 - Present) The 5 th Tongji-UBC Symposium on Earthquake Engineering “Facing Earthquake Challenges Together” May 4-8 2015, Tongji University Shanghai, China
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Ambient Vibration Tests and Model Updating of the Health Sciences Parkade at UBC ILARIA CAPRARO Supervisor: Dr. Carlos E. Ventura MASc | University of.
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Ambient Vibration Tests and Model Updating of the Health Sciences
Parkade at UBC
ILARIA CAPRAROSupervisor: Dr. Carlos E. Ventura
MASc | University of Bologna, Italy (2012)
PhD Student | The University of British Columbia, Canada (2014 - Present)
The 5th Tongji-UBC Symposium on Earthquake Engineering “Facing Earthquake Challenges Together” May 4-8 2015, Tongji University Shanghai, China
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Outline• Description of the Health Sciences Parkade;
• Two different Ambient Vibration Tests: Normal operational conditions; Almost empty environment;
• Modal frequencies and mode shapes evaluation;
• Comparison between the results obtained with the two different tests;
• Sensitivity analysis and modal updating;
• Examples of seismic retrofits on the Parkade;
• Conclusions and future work.
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Description of the HSPTwo 4-storey reinforced concrete buildings; Sets of three ramps each level; LFRS: shear walls and Moment Resisting Frame; External shear walls introduce stiffness irregularity
• Sampling frequency 256 Hz;• GPS synchronization;• Operational conditions → high levels of traffic.
Reference Sensor
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ARTeMIS Model
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Frequency Domain Analysis
FDD: Frequency Domain Decomposition• Vertical channels not included in the analysis;• Re-sampling at 128 Hz;• 1024 frequency lines;• Decimation: 0 – 32 Hz;• Six modes identified up to 8 Hz.
Time Domain Analysis
SSI-UPC: Stochastic Subspace Identification• Natural frequencies and modal damping values evaluated;• High values for modal damping;
← Stabilization diagram for Setup 4.
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1st Mode Shape: 2.756 HzN – S Longitudinal
N - S
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T
2nd Mode Shape: 3.894 HzTorsional
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E - W
3rd Mode Shape: 4.413 HzE – W Transversal
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T
4th Mode Shape: 5.781 HzTorsional
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Mode #Frequency [Hz]
CommentFDD
1 2.7561 st N-S Longitudinal
2 3.894 1 st Torsional
3 4.4131 st E-W Transversal
4 5.781 2 nd Torsional
5 7.2442 nd N-S Longitdinal
6 7.9443 rd N-S Longitudinal
Summary of the Results
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AVT in almost empty environment• Just the reference sensor used at the same location as previously;• Test performed late in the day;• Recording duration and sampling frequency same as the complete AVT.
Reference Sensor
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Comparison between the two AVTs
•1st natural frequency is ~ 12% higher when traffic is present;• Vertical component of vibration is predominant between 10-20 Hz;• Strong amplification due to traffic load;• The change in mass between the two tests did not affect significantly the natural frequencies of the structure.