Search

found 2009 results

Images, UC QuakeStudies

A "drummer boy" dummy dressed in a hi-vis jacket sits on top of a building on High Street. Written on the back of the building is "Merry Christmas Christchurch Pa Rum Pum Pum Pum". Te Waiponamu House is visible in the background.

Images, UC QuakeStudies

People cast flowers into the Avon River during the River of Flowers event held in Riccarton Bush, commemorating the second anniversary of the 22 February earthquake. In the background is the string quartet from Christchurch Girls High School which played before the event.

Images, UC QuakeStudies

The Forsyth Barr building stands alone, the buildings around it demolished. The photographer comments, "High-rise buildings look totally out of proportion when there's nothing around them to give them context. The jutting out part of this one makes it look unbalanced".

Images, UC QuakeStudies

A view down High Street from the corner of Colombo and Hereford Streets. In the distance, the Holiday Inn City Centre is being demolished. Taken on a day when a walkway was opened up between Re:Start Mall and Cathedral Square to allow temporary public access.

Research papers, University of Canterbury Library

Supplemental energy dissipation devices are increasingly used to protect structures, limit loads transferred to structural elements and absorbing significant response energy without sacrificial structural damage. Lead extrusion dampers are supplemental energy dissipation devices, where recent development of smaller volumetric size with high force capacities, called high force to volume (HF2V) devices, has seen deployment in a large series of scaled and full-scaled experiments, as well as in three new structures in Christchurch, NZ and San Francisco, USA. HF2V devices have previously been designed using limited precision models, so there is variation in force prediction capability. Further, while the overall resistive force is predicted, the knowledge of the relative contributions of the different internal reaction mechanisms to these overall resistive forces is lacking, limiting insight and predictive accuracy in device design. There is thus a major need for detailed design models to better understand force generation, and to aid precision device design. These outcomes would speed the overall design and implementation process for uptake and use, reducing the need for iterative experimental testing. Design parameters from 17 experimental HF2V device tests are used to create finite element models using ABAQUS. The analysis is run using ABAQUS Explicit, in multiple step times of 1 second with automatic increments, to balance higher accuracy and computational time. The output is obtained from the time- history output of the contact pressure forces including the normal and friction forces on the lead along the shaft. These values are used to calculate the resistive force on the shaft as it moves through the lead, and thus the device force. Results of these highly nonlinear, high strain analyses are compared to experimental device force results. Model errors compared to experimental results for all 17 devices ranged from 0% to 20% with a mean absolute error of 6.4%, indicating most errors were small. In particular, the standard error in manufacturing is SE = ±14%. In this case, 15 of 17 devices (88%) are within ±1SE (±14%) and 2 of 17 devices (12%) are within ±2SE (±28). These results show low errors and a distribution of errors compared to experimental results that are within experimental device construction variability. The overall modelling methodology is objective and repeatable, and thus generalizable. The exact same modelling approach is applied to all devices with only the device geometry changing. The results validate the overall approach with relatively low error, providing a general modelling methodology for accurate design of HF2V devices.

Research papers, University of Canterbury Library

A 3D high-resolution model of the geologic structure and associated seismic velocities in the Canterbury, New Zealand region is developed utilising data from depthconverted seismic reflection lines, petroleum and water well logs, cone penetration tests, and implicitly guided by existing contour maps and geologic cross sections in data sparse subregions. The model, developed using geostatistical Kriging, explicitly represents the significant and regionally recognisable geologic surfaces that mark the boundaries between geologic units with distinct lithology and age. The model is examined in the form of both geologic surface elevation contour maps as well as vertical cross sections of shear wave velocity, with the most prominent features being the Banks Peninsula Miocene-Pliocene volcanic edifice, and the Pegasus and Rakaia late Mesozoic-Neogene sedimentary basins. The adequacy of the modelled geologic surfaces is assessed through a residual analysis of point constraints used in the Kriging and qualitative comparisons with previous geologic models of subsets of the region. Seismic velocities for the lithological units between the geologic surfaces have also been derived, thus providing the necessary information for a Canterbury velocity model (CantVM) for use in physics-based seismic wave propagation. The developed model also has application for the determination of depths to specified shear wave velocities for use in empirical ground motion modelling, which is explicitly discussed via an example.

Research papers, The University of Auckland Library

The Manchester Courts building was a heritage building located in central Christchurch (New Zealand) that was damaged in the Mw 7.1 Darfield earthquake on 4 September 2010 and subsequently demolished as a risk reduction exercise. Because the building was heritage listed, the decision to demolish the building resulted in strong objections from heritage supporters who were of the opinion that the building had sufficient residual strength to survive possible aftershock earthquakes. On 22 February 2011 Christchurch was struck by a severe aftershock, leading to the question of whether building demolition had proven to be the correct risk reduction strategy. Finite element analysis was used to undertake a performance-based assessment, validating the accuracy of the model using the damage observed in the building before its collapse. In addition, soil-structure interaction was introduced into the research due to the comparatively low shear wave velocity of the soil. The demolition of a landmark heritage building was a tragedy that Christchurch will never recover from, but the decision was made considering safety, societal, economic and psychological aspects in order to protect the city and its citizens. The analytical results suggest that the Manchester Courts building would have collapsed during the 2011 Christchurch earthquake, and that the collapse of the building would have resulted in significant fatalities.

Images, UC QuakeStudies

A photograph of a digger and workers in high-visibility gear outside a badly-damaged building on the corner of Gloucester Street and Manchester Street. The road is covered in building rubble and has been cordoned off with wire fencing.

Images, UC QuakeStudies

A photograph of a digger and workers in high-visibility gear outside a badly-damaged building on the corner of Gloucester Street and Manchester Street. The road is covered in building rubble and has been cordoned off with wire fencing.

Images, UC QuakeStudies

Emergency management personnel, in hard hats and high-visibility vests, making phone calls outside the Christchurch Art Gallery shortly after the 22 February 2011 earthquake. The Arts Gallery was used as Civil Defence Headquarters after the 22 February 2011 earthquake.

Images, UC QuakeStudies

Looking down High Street from Colombo Street. A public walkway down Colombo Street to a small viewing area in the Square was opened up for a few weekends to allow the public to see inside the Red Zone. The partially demolished Grand Chancellor is visible in the background.

Images, UC QuakeStudies

Warped bike stands and liquefaction silt on the corner of High, Colombo and Hereford streets. A public walkway down Colombo Street to a small viewing area in the Square was opened up for a few weekends to allow the public to see inside the Red Zone.