Recent seismic events, such as the 2010-2011 Canterbury earthquakes and the 2016 Kaikōura earthquakes, have shed light on issues with the seismic performance of glazing systems. This is attributed to the limited amount of research and consideration of glazing systems in design and assessments. Previous research and evidence from post-earthquake reconnaissance have shown that glazing systems pose a hazard due to falling glass. As such, it is vital to ensure that glazing systems are designed with the necessary levels of seismic performance. Furthermore, the post-earthquake repair of glass facades can be costly and time-consuming. Some previous research has been conducted to highlight the seismic performance and fragility of glazing systems. However, most prior research only focussed on life-safety issues of glazing systems and rarely on the serviceability of glazing systems. The serviceability of glazing systems, such as water-tightness, is a vital aspect of glazing systems as a low serviceability capacity will increase the likelihood of further damage which will increase economic losses. This is the aim of this research, to provide insight towards the seismic performance of glazing systems considering both the serviceability and ultimate limit state by generating insight into the behaviour of glazing systems and developing tools for the consideration of glazing systems in design and assessment. This will allow a value proposition for seismic detailing of glazing to be evaluated. In order to provide insight into the behaviour of glazing systems and a means for evaluating their seismic performance, this research firstly develops an applicable experimental testing procedure that allows for serviceability limit state tests on glazing units. This experimental testing procedure is used to obtain data on the vulnerability of general New Zealand glazing systems’ performance, specifically unitised glazing systems that are commonly used as commercial shopfront glazing system types. These glazing systems typically realised using aluminium framing with gaskets connecting the frame to the glass. After the experimental testing, numerical analyses calibrated to the experimental testing results are conducted to enable robust analyses of glazing systems’ fragility. Finally, a value proposition for glazing systems with seismic detailing is made by comparing the performance of glazing systems with seismic detailing and conventional glazing systems. This comparison is done using the PEER-PBEE method and the economic implications of each glazing system is shown. Suggestions for designers and stakeholders aimed at reducing costs related to the seismic performance of glazing systems is also shown. Using the novel experimental method developed in this research, three different full-scale glazing systems were tested. A total of 10 unitised glazing specimens were tested; three with standard detailing, three with seismic detailing and four that were structurally glazed. These tests evaluated three damage states (DS): loss of water-tightness (DS1), gasket damage (DS2), and glass or framing failure (DS3). The experimental method that was adopted is considered to be more desirable than the optional procedures set out in New Zealand glazing standards. The method does not require high-speed testing equipment and is easy to replicate by the industry. The test results show that water-tightness was lost at low drift levels, with the first leakage occurring at just 0.15% drift for one specimen, while a standard glazing system had a median drift capacity of 0.35%. In contrast, seismic glazing systems detailed to better accommodate in-plane movements, demonstrated a significantly higher median drift capacity of 1.88%. The numerical approach proposed in this research has shown that it is possible to numerically model the glazing-gasket interaction to conservatively predict the water-leakage drift (damage state 1). The modelling approach still needs further development if it were to be used for damage states DS2 and DS3. The last part of the research considered the value proposition for seismic glazing systems. This was achieved by applying the FEMA P-58 performance assessment framework to a number of case study buldings that are typical of New Zealand design. The results suggest that it may not be economically worthwhile to use well-detailed seismic glazing systems despite the considerably larger drift capacity they possess relative to standard systems. However, as the cost of seismic glazing systems reduces, and more information on repair costs for different damage states is obtained, the value proposition may change.
- The Avon-Ōtākaro Redzone is an 11 kilometer stretch of land along the Avon-Ōtākaro River in Christchurch. - This project focused on the creation of a publicly available biodiversity map of the AvonŌtākaro River Corridor, a project undertaken as part of the ecological restoration of the Christchurch redzone. - This project originated from the Christchurch 2010-2011 earthquake sequence which saw liquefaction damage along 11km of the Avon River. Under guidance from The Nature Lab & Ōtākaro Living Laboratory, and various other experts, the primary research objective was to map historical biodiversity, identify hotspots, and assess areas for potential revegetation. - The data collected came from historical black maps, current iNaturalist data, and soil classification information. - The findings show that, pre-colonialism, the area was composed of herbaceous areas, wetlands, native shrubland, and tussock land, with key plants such as river, fern, tutu, and cabbage trees. - The post-earthquake analysis shows a transition from a residential area to patchy grasslands and swampy areas. - The findings also showed a strong relationship between historic sites and soil classifications, providing knowledge for past and future vegetation patterns and spread. - This map will be a valuable resource for conservation efforts and public engagement as the area transitions into a blue-green corridor.
From small coastal settlements to large cities, communities are exposed to both the direct and indirect consequences of climate-change induced sea-level rise (SLR). Above the ground surface, short- and long-term coastal effects of SLR are visible and cause damage from flooding, erosion, and loss of habitats and ecosystems. Below the ground surface, the effects are less visible but nonetheless extensive. Groundwater is present at shallow depth in the coastal zone and the effects of SLR on shallow groundwater threaten water security, agricultural production and infrastructure. Groundwater flooding, a hydrological hazard results from the process of water table rise, where the groundwater surface intersects or goes above the land surface due to changing conditions. The coastal zone is a complex dynamic space between saltwater and freshwater environments above and below the ground surface, and coastal groundwater hazards are intensified due to SLR. However, current monitoring of coastal shallow groundwater levels and salinity does not occur sufficiently to mitigate and adapt to the groundwater hazard. This thesis provides insights into the dynamics of coastal shallow groundwater, urban monitoring networks, simulations of water table rise and the issues posed by shallow groundwater changes driven by SLR and effects on flooding. The first study reviewed processes of coastal groundwater rise and simulation tools used to evaluate possible impacts of SLR. The benefits and limitations of the two main methods to assess coastal groundwater rise and its contribution to flooding - spatial interpolation and numerical tools - were discussed. The review highlighted the need for methodology comparisons between spatial interpolation and numerical tools to guide future work. The simulation tools that are used to evaluate changes in urban hydrogeology due to SLR do not specifically estimate groundwater flooding. Current monitoring practices do not capture evidence for groundwater rise with SLR. Therefore, the assessment methods need to rely on improved coastal groundwater monitoring networks focused on water quality, saltwater intrusion, and continuous groundwater levels records near the coastline, tidally influenced surface water bodies, and critical infrastructure. The second study focused on an urban shallow groundwater monitoring network and assessed its development, current physical condition and usefulness for SLR research. Following the 2010-2011 Canterbury Earthquake Sequence, in Otautahi Christchurch, ¯ Aotearoa New Zealand, shallow groundwater data acquisition and establishment of a geotechnical database provided unprecedented information on subsurface conditions. The monitoring infrastructure provided high spatio-temporal resolution records of shallow groundwater levels, which opened the field of New Zealand-based urban groundwater studies. Field surveys and digital information reviews showed that the monitoring net work was in overall good condition and robust, despite some maintenance issues. The dataset held by the city and regional councils should be more widely used to benefit the community, urban water management, researchers and practitioners, facing decisions to adapt and protect coastal areas from the impacts of climate change and SLR. The third study determined characteristics of shallow groundwater, including spatial and temporal trends in depths to groundwater and their relationship to natural and an thropogenic stressors. The study used depth to groundwater measurements from the uniquely extensive and densely spaced monitoring network in Otautahi Christchurch, ¯ Aotearoa New Zealand. Data-driven analysis approaches were applied, including spa tial interpolation, autocorrelation, clustering, cross-correlation, and trend analysis. This comprehensive approach revealed discernible clusters and trends within the dataset, pro viding valuable insights into the spatial and temporal variability of shallow groundwater in urban coastal settings. Responses to stresses such as rainfall events and stream flow were successfully classified using clustering analysis, while anthropogenic influences were more challenging. The primary feature in hydrograph classification proved to be the prox imity to tidal rivers and their correlation with tidal signals. This study highlighted the importance of monitoring coastal groundwater and the need for a better understanding of its effects on urban infrastructure and the built environment. The fourth study focused on simulating the effects of SLR on water table rise. These processes may lead to groundwater flooding and infrastructure challenges. A numerical model was used to assess the transient water table movement in response to SLR. Various SLR scenarios and rates were used to simulate the magnitudes and rates of water table rise, considering a range of aquifer parameters for both fixed-head and fixed-flux inland boundary conditions. The magnitudes and rates of water table rise were always less than but proportional to SLR and decreased with distance from the coastline. The magnitude and rate of water table rise in response to SLR were the largest for fixed flux inland boundary conditions, but it takes a long time for conditions to equilibrate. Fixed-flux conditions were found to pose a greater hazard as the maximum impact may not be experienced for decades, posing challenges to planners and managers of coastal groundwater systems. Adding a drain reduced the magnitude and rate of water table rise, more on the inland side than on the coastal side. The final study examined the key impacts of SLR on coastal shallow groundwater, and subsequent challenges faced by infrastructure asset managers. The study showed that current and future issues such as saltwater intrusion, flooding, and earthquake liquefaction hazard due to groundwater are exacerbated by climate change-driven SLR. A key issue is determining who will take responsibility for shallow groundwater management in areas with multiple and overlapping local government jurisdictions. Another key finding is that current techniques to manage groundwater in infrastructure construction/operation and land management will be applied in future, and challenges to coastal infrastructure adaptation will be posed by political and economic considerations rather than technical understanding.
