A temporary road sign indicates that the speed limit is 10 km/h along Rocking Horse Road in Southshore, due to the uneven surface of the road.
A photograph of Sumner and the Avon-Heathcote estuary taken prior to the 4 September 2010 earthquake. Shag Rock is visible near the centre of the photograph.
Photograph captioned by BeckerFraserPhotos, "Road signs near the container barrier at Peacocks Gallop indicating that there is a danger of rock fall in the area".
A photograph of Sumner and the Avon-Heathcote estuary taken prior to the 4 September 2010 earthquake. Shag Rock is visible near the centre of the photograph.
A photograph of Sumner beach and the Avon-Heathcote estuary taken prior to the 4 September 2010 earthquake. Shag Rock is visible at the left of the photograph.
A photograph of Sumner beach and the Avon-Heathcote estuary taken prior to the 4 September 2010 earthquake. Shag Rock is visible to the left of the photograph.
A sculpture of a rock climber that has been installed on the steel bracing that has been placed on the tower of the Octagon Live Restaurant (formerly Trinity Church).
Photograph captioned by BeckerFraserPhotos, "Inside the Sumner electrical sub-station which was severely damaged by rock fall from the cliffs above during the 22 February 2011 earthquake.
Photograph captioned by BeckerFraserPhotos, "Inside the Sumner electrical sub-station which was severely damaged by rock fall from the cliffs above during the 22 February 2011 earthquake.
A line of shipping containers along the base of the cliffs in Sumner protects the road from rockfalls. In the foreground on the right is what remains of Shag Rock.
A rubbish truck collects rubbish from the red bins along Rocking Horse Road in Southshore. The uneven surface of the road can be seen, with water pooling in the foreground.
An aerial photograph captioned by BeckerFraserPhotos, "The RSA (red roof and three skylights) and electrical substation (red front with the door open) very badly damaged by the rock falls".
A damaged house teetering on the edge of the cliff in Sumner. The photographer comments, "About four meters of the rock face collapsed on June 13 undermining several houses along the cliff top".
A photograph of section of an artwork on the wall of a building between New Brighton mall and Beresford Street. The section depicts a native bird standing on a rock in front of a kowhai tree.
Structural damage to St Elmo Courts with diagonal cracks between the windows of the building. These cracks show that there has been rocking of the masonry piers which means there is no vertical reinforcement provided in the walls.
A photograph captioned by BeckerFraserPhotos, "The Cave House, well known for its bright colour, on Main Road in Redcliffs. The house was further demolished by the most recent rock fall in the 23 December 2011 earthquake".
Large boulders which have fallen among houses at the base of the cliffs in Redcliffs. In the foreground a shipping container blocks access to the driveway. The photographer comments, "Now this is one very huge rock to have land in your front yard".
The Octagon Live Restaurant (formerly Trinity Church) on Worcester Street. Bracing has been placed on the tower to limit further damage from aftershocks. Sculptures of a cyclist, bungee jumper , rock climber and kayaker can be seen on the bracing posts.
A damaged house teetering on the edge of the cliff in Sumner. Below, shipping containers along the edge of Peacock's Gallop protect the road from further rockfall. The photographer comments, "About four meters of the rock face collapsed on June 13 undermining several houses along the cliff top".
A digital copy of a painting by Hamish Allan. The painting is titled, 'Garden City III, Tunnel control' and was painted in 2013. The original painting is acrylic on linen and measures 400 by 400mm.
A painting wrapped around the side of one of the shipping containers in Sumner. Shipping containers have been placed along Main Road to protect people from rock fall. The artwork is part of the ContainerArt project which aims to turn the fixture of shipping containers in the Sumner community into a positive by turning them into works of art.
A photograph of an All Right? advertisement in a newspaper. The advertisement depicts an 'All Rightie' listening to music and dancing, and reads, "Classical? Jazz? Punk rock? Everyone needs to let their hair down now and then." All Right? posted the photograph on their Facebook page on 13 September 2013 at 4:10pm.
The Christchurch earthquakes have highlighted the importance of low-damage structural systems for minimising the economic impacts caused by destructive earthquakes. Post-tensioned precast concrete walls have been shown to provide superior seismic resistance to conventional concrete construction by minimising structural damage and residual drifts through the use of a controlled rocking mechanism. The structural response of unbonded post-tensioned precast concrete wall systems, with and without additional energy dissipating elements, were investigated by means of pseudo-static cyclic, snap back and forced vibration testing with shake table testing to be completed. Two types of post-tensioned rocking wall system were investigated; a single unbonded post-tensioned precast concrete wall or Single Rocking Wall (SRW) and a system consisting of a Precast Wall with End Columns (PreWEC). The equivalent viscous damping (EVD) was evaluated using both the pseudo-static cyclic and snap back test data for all wall configurations. The PreWEC configurations showed an increase in EVD during the snap back tests in comparison to the cyclic test response. In contrast the SRW showed lower EVD during the snap back tests in comparison to the SRW cyclic test response. Despite residual drifts measured during the pseudo-static cyclic tests, negligible residual drift was measured following the snap back tests, highlighting the dynamic shake-down that occurs during the free vibration decay. Overall, the experimental tests provided definitive examples of the behaviour of posttensioned wall systems and validated their superior performance compared to reinforced concrete construction when subjected to large lateral drifts.
A PDF copy of eight posters promoting the Five Ways to Wellbeing at local libraries. Each poster directs its viewer to explore a section of the library by encouraging them to reflect on different hobbies and interests, for example cooking, painting, exercise, reading or music. The first poster reads, "Want a tasty recipe for the whanau? Good food tastes even better with the ones we love. For recipe books check out 641.5!". This set of posters differs from the other sets of library posters in that the poster that reads, "When did you last really rock out?" contains the Fregal logo.
Heathcote Valley school strong motion station (HVSC) consistently recorded ground motions with higher intensities than nearby stations during the 2010-2011 Canterbury earthquakes. For example, as shown in Figure 1, for the 22 February 2011 Christchurch earthquake, peak ground acceleration at HVSC reached 1.4 g (horizontal) and 2 g (vertical), the largest ever recorded in New Zealand. Strong amplification of ground motions is expected at Heathcote Valley due to: 1) the high impedance contrast at the soil-rock interface, and 2) the interference of incident and surface waves within the valley. However, both conventional empirical ground motion prediction equations (GMPE) and the physics-based large scale ground motions simulations (with empirical site response) are ineffective in predicting such amplification due to their respective inherent limitations.
1. INTRODUCTION. Earthquakes and geohazards, such as liquefaction, landslides and rock falls, constitute a major risk for New Zealand communities and can have devastating impacts as the Canterbury 2010/2011 experience shows. Development patterns expose communities to an array of natural hazards, including tsunamis, floods, droughts, and sea level rise amongst others. Fostering community resilience is therefore vitally important. As the rhetoric of resilience is mainstreamed into the statutory framework, a major challenge emerges: how can New Zealand operationalize this complex and sometimes contested concept and build ‘community capitals’? This research seeks to provide insights to this question by critically evaluating how community capitals are conceptualized and how they can contribute to community resilience in the context of the Waimakariri District earthquake recovery and regeneration process.
Soil-structure interaction (SSI) has been widely studied during the last decades. The influence of the properties of the ground motion, the structure and the soil have been addressed. However, most of the studies in this field consider a stand-alone structure. This assumption is rarely justifiable in dense urban areas where structures are built close to one another. The dynamic interaction between adjacent structures has been studied since the early 1970s, mainly using numerical and analytical models. Even though the early works in this field have significantly contributed to understanding this problem, they commonly consider important simplifications such as assuming a linear behaviour of the structure and the soil. Some experimental works addressing adjacent structures have recently been conducted using geotechnical centrifuges and 1g shake tables. However, further research is needed to enhance the understanding of this complex phenomenon. A particular case of SSI is that of structures founded in fine loose saturated sandy soil. An iconic example was the devastating effects of liquefaction in Christchurch, New Zealand, during the Canterbury earthquake in 2011. In the case of adjacent structures on liquefiable soil, the experimental evidence is even scarcer. The present work addresses the dynamic interaction between adjacent structures by performing multiple experimental studies. The work starts with two-adjacent structures on a small soil container to expose the basics of the problem. Later, results from tests considering a more significant number of structures on a big laminar box filled with sand are presented. Finally, the response of adjacent structures on saturated sandy soil is addressed using a geotechnical centrifuge and a large 1g shake table. This research shows that the acceleration, lateral displacement, foundation rocking, damping ratio, and fundamental frequency of the structure of focus are considerably affected by the presence of neighbouring buildings. In general, adjacent buildings reduced the dynamic response of the structure of focus on dry sand. However, the acceleration was amplified when the structures had a similar fundamental frequency. In the case of structures on saturated sand, the presence of adjacent structures reduced the liquefaction potential. Neighbouring structures on saturated sand also presented larger rotation of the footing and lateral displacement of the top mass than that of the stand-alone case.
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.