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Research papers, Lincoln University

An emerging water crisis is on the horizon and is poised to converge with several other impending problems in the 21st century. Future uncertainties such as climate change, peak oil and peak water are shifting the international focus from a business as usual approach to an emphasis on sustainable and resilient strategies that better meet these challenges. Cities are being reimagined in new ways that take a multidisciplinary approach, decompartmentalising functions and exploring ways in which urban systems can share resources and operate more like natural organisms. This study tested the landscape design implications of wastewater wetlands in the urban environment and evaluated their contribution to environmental sustainability, urban resilience and social development. Black and grey water streams were the central focus of this study and two types of wastewater wetlands, tidal flow (staged planning) and horizontal subsurface flow wetlands were tested through design investigations in the earthquake-affected city of Christchurch, New Zealand. These investigations found that the large area requirements of wastewater wetlands can be mitigated through landscape designs that enhance a matrix of open spaces and corridors in the city. Wastewater wetlands when combined with other urban and rural services such as food production, energy generation and irrigation can aid in making communities more resilient. Landscape theory suggests that the design of wastewater wetlands must meet cultural thresholds of beauty and that the inclusion of waste and ecologies in creatively designed landscapes can deepen our emotional connection to nature and ourselves.

Research papers, University of Canterbury Library

8-pages Special devices can be used to minimize structural damage by energy dissipation or seismic isolation. This research considers High Force-to-Volume (HF2V), Symmetric Friction Connection (SFC), Asymmetric Friction Connection (AFC) and Linear-Elastic Isolators (LEI). Device architectures connecting column-to-deck and ground-to-deck are also compared. Bridge columns are assumed to remain elastic. Performance of bridge columns (peak and residual displacement) under 20 probabilistically scaled ground motions is assessed in spectral analysis (0.1-5.0sec) using reduction factors compared to a fixed, no-device case. Energy dissipating devices have minimum column displacement reduction factors when placed between the column and the deck for rigid connection system periods up to ~2.5s. Above that fundamental period, dissipating devices connecting ground-to-deck provide the optimum configuration. Residual displacements obtained when the energy dissipators are placed between the column and the deck are larger than those of the ground to deck case for periods below ~3.7s. Above this 3.7s, frictional dissipators in the column to deck case are more efficient, but HF2V devices connecting ground to deck remain as the best alternative with no residual displacements. The performance curves obtained in this research provide design guidelines for the best device and configuration applicable to a broad range of bridge structures.