System Identification and Modeling of An 18-Story Building in Nepal Using Post-Earthquake Ambient Vibration Data


Abstract eng:
Investigating structures damaged by strong earthquakes can provide valuable insight in understanding the performance of structures during such events. Few studies have been conducted on structures using post-earthquake vibration data to assess their state of health/performance. This paper presents such a study by considering an 18-story apartment building damaged during the 7.8 Gorkha Earthquake that occurred in Nepal in April 25, 2015. The building was instrumented with 15 accelerometers in two configurations that measured its ambient vibration response. The recorded data is analyzed and the modal parameters of the test structure are identified using the Natural Excitation Technique combined with Eigensystem Realization Algorithm (NExT-ERA), an output-only system identification method. Moreover, a newly developed simplified analytical tool is used to simulate the response of the structure. This tool allows the estimation of the base shear-vs.displacement curve for the structure in two orthogonal dimensions. A linear finite element (FE) model of the building was also developed. Masonry infill wall panels are modeled using the equivalent diagonal strut method approach. The building FE model is based on the geometry of the building and its material properties to estimate numerically the dynamic characteristics of the test structure. The identified modal parameters are compared to those obtained from the FE model to identify possible shortcomings of the identification and modeling approaches. It is observed that the identified natural frequency and mode shape of the first vibration mode are in reasonable agreement with the one obtained from the FE model. However, no such agreement is observed for the higher modes.

Contributors:
Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 3557.:
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