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Research papers, The University of Auckland Library

The full scale, in-situ investigations of instrumented buildings present an excellent opportunity to observe their dynamic response in as-built environment, which includes all the real physical properties of a structure under study and its surroundings. The recorded responses can be used for better understanding of behavior of structures by extracting their dynamic characteristics. It is significantly valuable to examine the behavior of buildings under different excitation scenarios. The trends in dynamic characteristics, such as modal frequencies and damping ratios, thus developed can provide quantitative data for the variations in the behavior of buildings. Moreover, such studies provide invaluable information for the development and calibration of realistic models for the prediction of seismic response of structures in model updating and structural health monitoring studies. This thesis comprises two parts. The first part presents an evaluation of seismic responses of two instrumented three storey RC buildings under a selection of 50 earthquakes and behavioral changes after Ms=7.1 Darfield (2010) and Ms=6.3 Christchurch (2011) earthquakes for an instrumented eight story RC building. The dynamic characteristics of the instrumented buildings were identified using state-of-the-art N4SID system identification technique. Seismic response trends were developed for the three storey instrumented buildings in light of the identified frequencies and the peak response accelerations (PRA). Frequencies were observed to decrease with excitation level while no trends are discernible for the damping ratios. Soil-structure interaction (SSI) effects were also determined to ascertain their contribution in the seismic response. For the eight storey building, it was found through system identification that strong nonlinearities in the structural response occurred and manifested themselves in all identified natural frequencies of the building that exhibited a marked decrease during the strong motion duration compared to the pre-Darfield earthquakes. Evidence of foundation rocking was also found that led to a slight decrease in the identified modal frequencies. Permanent stiffness loss was also observed after the strong motion events. The second part constitutes developing and calibrating finite element model (FEM) of the instrumented three storey RC building with a shear core. A three dimensional FEM of the building is developed in stages to analyze the effect of structural, non-structural components (NSCs) and SSI on the building dynamics. Further to accurately replicate the response of the building following the response trends developed in the first part of the thesis, sensitivity based model updating technique was applied. The FEMs were calibrated by tuning the updating parameters which are stiffnesses of concrete, NSCs and soil. The updating parameters were found to generally follow decreasing trends with the excitation level. Finally, the updated FEM was used in time history analyses to assess the building seismic performance at the serviceability limit state shaking. Overall, this research will contribute towards better understanding and prediction of the behavior of structures subjected to ground motion

Videos, UC QuakeStudies

A video clip of a large-scale, temporary installation titled Upload. The installation was created by students from The University of Auckland for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of a large-scale, temporary installation titled Equilibrium. The installation was created by students from The University of Auckland for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of a large-scale, temporary installation titled Equilibrium. The installation was created by students from The University of Auckland for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip depicting part of a large-scale, temporary installation titled Antigravity. The installation was created by students from The University of Auckland for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of two large-scale, temporary installations titled Upload (left) and Equilibrium (right). The installations were created by students from The University of Auckland, for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of a large-scale, temporary installation titled ScopeCity. The installation is on Manchester Street. The installation was created by students from Unitec for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of two large-scale, temporary installations titled Aurora (front) and Synthesis (back, left). The installations were created by students from Unitec and CPIT, for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of two large-scale, temporary structures, titled Synthesis and Aurora, being installed by students from CPIT and Unitec. The installations were part of CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of a large-scale, temporary installation titled GlowCity. The installation is on Manchester Street. The installation was created by students from Unitec for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of a large-scale, temporary installation titled GlowCity. The installation is on Manchester Street. The installation was created by students from Unitec for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of two large-scale, temporary installations titled Aurora (front) and Synthesis (back, left). The installations were created by students from Unitec and CPIT, for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of people dancing inside a large-scale, temporary installation titled Equilibrium. The installation was created by students from The University of Auckland for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of a large-scale, temporary installation titled Synthesis. The installation is on the corner of High Street. The installation was created by students from CPIT for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of a large-scale, temporary installation titled Antigravity. The installation is on Lichfield Street. The installation was created by students from The University of Auckland for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of several large-scale, temporary installations on the corner of High and Lichfield Streets, and the corner of Lichfield and Manchester Streets. The installations are part of CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of people walking through a large-scale, temporary installation titled ScopeCity. The installation is on Manchester Street. The installation was created by students from Unitec for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.

Videos, UC QuakeStudies

A video clip of children playing with inflatable balls inside a large-scale, temporary installation titled Upload. The installation was created by students from The University of Auckland for CityUps - a 'city of the future for one night only', and the main event of FESTA 2014.