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Research papers, University of Canterbury Library

This community-partnered thesis explores the impact of ReVision Youth Audits in promoting youth-friendly community spaces in Christchurch, a city undergoing long-term urban transformation following the 2010–2011 earthquakes. In partnership with ReVision, a not-for-profit organisation facilitating youth-led audits of public and community spaces, this research examines how audit recommendations have been implemented by organisations responsible for 23 previously audited sites. Using a mixed-methods approach, including an online stakeholder survey (n = 16) and semi-structured interviews (n = 2), the study identified variation in implementation outcomes, with non-profit organisations reporting higher adoption levels than local government entities. Stakeholders reported that commonly implemented recommendations included enhanced lighting, inclusive signage, additional seating, and youth-focused amenities such as murals, free Wi-Fi, and gender-neutral toilets. The average youth-friendliness score increased from 4.7 to 7.5 out of 10 following implementations, reflecting tangible improvements in accessibility, inclusivity, and youth engagement. Despite these gains, several barriers limited full implementation. Local government stakeholders cited procedural delays, regulatory frameworks, and funding cycles tied to long- term planning. At the same time, non-profits stakeholders faced constraints such as property ownership and limited influence over shared spaces. Challenges related to timing, staffing capacity, and the absence of follow-up mechanisms were also reported. Stakeholders recomended integrating youth input in the design process earlier, as several audits occurred after key planning phases. Feedback on the audit process was largely positive, with high ratings for the clarity of recommendations and the tool's credibility. However, stakeholders advocated for refinements when recording the audit recommendations to capture young people's lived experiences better and sustain youth involvement beyond the initial audit phase. The research demonstrates that the ReVision Youth Audit framework contributes to meaningful improvements in public spaces especially for youth and reinforces the value of youth-informed urban design. This research provides practical guidance for enhancing youth engagement in urban planning and improving the long-term utility of participatory audit frameworks, based on an analysis of both the factors that enabled and those that constrained the implementation of audit recommendations.

Research papers, University of Canterbury Library

Most people exposed to disasters cope well. Others, however, develop posttraumatic stress disorder (PTSD)–a mental disorder characterised by symptoms of intrusion, avoidance, and hyperarousal–requiring input from specialist mental health services. To date, relatively little research has evaluated these services, and less is known about characteristics of people seeking treatment and their treatment outcomes. In 2010 and 2011, a series of major earthquakes occurred in the Canterbury region of Aotearoa New Zealand, resulting in initiation of the Adult Specialist Services for Earthquake Trauma Treatment (ASSETT) service to provide cognitive behavioural therapy (CBT) for people with earthquake-related PTSD or subthreshold PTSD symptoms. The current research used systematic literature review methods, in conjunction with data collected from people seeking treatment with the ASSETT service, to address issues relevant to the development of disaster mental health responses, particularly specialist mental health services. A systematic review was conducted synthesising research examining mental health service use among adults exposed to natural disasters. A second systematic review and meta-analysis evaluated psychological interventions for earthquake-related PTSD. A series of studies then utilised diagnostic interview and self-report data collected from people seeking treatment with the ASSETT service (n = 184). Data were collected on factors relating to sociodemographics, pre-earthquake mental disorders, current psychological functioning, degree of objective and subjective earthquake exposure, and life events. These studies examined factors distinguishing treatment-seeking participants from earthquake-exposed Canterbury residents who coped well; differences associated with different prior mental disorders and timing of treatment presentation; and outcomes of CBT provided by the service. Four overarching themes emerged across study findings. The first related to the role of objective and subjective disaster exposure in the development of post-disaster mental health outcomes. Subjective peritraumatic responses were found to be an important factor distinguishing treatment-seeking participants from those who coped well following the earthquakes, independent of objective exposure severity. Heightened peritraumatic responses were also associated with poorer treatment outcome, although not beyond their association with pre-treatment PTSD severity and degree of comorbidity. The second theme related to the role of pre-trauma mental health in the development of post-disaster mental health outcomes. Participants with a history of pre-earthquake mental disorder presented with more comorbid disorders than participants with no prior disorder, but reported comparable degrees of PTSD severity and similar treatment outcomes. The third theme related to temporal considerations for disaster mental health responses. Participants who presented at later time points tended to be older and were more likely to have subthreshold PTSD symptoms, but had similar treatment outcomes as those who presented at earlier time points. The fourth theme related to treatment of severe and ongoing earthquake-related distress. CBT without a formal exposure component was associated with clinically significant improvements on a range of outcome measures, with group and individual-based treatment associated with comparable outcomes. Findings of the current research suggest people seeking treatment for severe and ongoing disaster-related distress are not homogenous, and are likely to present for treatment at different time points, have varied mental health histories, and report diverse disaster experiences. CBT is an effective treatment for severe and ongoing post-disaster distress when delivered in real-world mental health service settings. Group CBT represents an efficient, scalable, and effective treatment format for post-disaster distress, and may be an attractive option for treating widespread need using limited resources.

Research papers, University of Canterbury Library

According to TS 1170.5, designing a building to satisfy code-prescribed criteria (e.g., drift limit, member safety, P-Δ stability) at the ultimate limit state and relying on the inherent margins within the design code would lead to an acceptable mean annual frequency of collapse (λ꜀) in the range of 10−⁴ to 10−⁵. Modern performance objectives, such as λ꜀ and expected annual loss (EAL), are not explicitly considered. Although buckling-restrained braced frame (BRBF) buildings were widely adopted as lateral load-resisting systems for office and car park buildings in the Christchurch rebuild following the Canterbury earthquakes in New Zealand, there are currently no official guidelines for their design. The primary focus of this study is to develop a risk-targeted design framework for BRBF buildings that can achieve the performance objectives desired by stakeholders. To this extent, key factors influencing λ꜀ and EAL of BRBF buildings are identified. These factors include gusset plate design, number of storeys, design drift limit, BRBF beam-column connection, brace configuration, brace angle, brace material grade, and analysis method (equivalent lateral force vs. modal response spectrum). A novel 3D BRBF modelling approach capable of simulating out-of-plane buckling failure of buckling-restrained brace (BRB) gusset plates is developed. Prior experimental studies on sub-assemblies conducted elsewhere have demonstrated that gusset plates and end zones may buckle out of plane prematurely, before BRBs reach their maximum axial compression load carrying capacity. Current 2D BRBF macro models, typically used in research, cannot simulate this failure mode. A conventional 2D BRBF model underestimates the λ꜀ of a case-study 4-storey super-X configured steel BRBF building (designed according to NZS-3404) by a factor of two compared to the estimate from the proposed 3D model. These findings suggest that the current NZS-3404 gusset plate design method may undersize gusset plates and that using a 2D BRBF model in this case can significantly underestimate λ꜀. Three improved alternative gusset plate design methods that are easy to implement in practice are identified from the literature. Gusset plates in two case-study 4-storey steel BRBF buildings with super-X and diagonal configurations are designed using both the NZS-3404 method and alternative methods. All three alternative design methods are found to be conservative, resulting in an almost three-fold lower λ꜀ for both case-study BRBF buildings compared to those designed using the NZS-3404 method. Analysis results indicate that (i) bidirectional interaction has no significant effect on gusset plate buckling and (ii) mid-span gusset plates are more susceptible to buckling than corner gusset plates. A framework for seismic loss assessment using incremental dynamic analysis (IDA), called loss-oriented hazard-consistent incremental dynamic analysis (LOHC-IDA), is developed. IDA can be conducted with a generic record set, eliminating the arduous site-specific record selection required to conduct multiple stripe analysis (MSA). Traditional IDA, however, is limited in producing hazard-consistent estimates of engineering demand parameters (EDPs), which LOHC-IDA overcomes. LOHC-IDA improves upon existing methods by: (i) incorporating correlations among engineering demand parameters across intensity levels and (ii) using peak ground acceleration (PGA) to predict peak floor acceleration (PFA). For two case-study steel BRBF buildings, LOHC-IDA estimates the EAL and loss distributions conditioned on the intensity level that closely match the MSA results, with an average absolute error of 5%. The influence of factors beyond gusset plate design on the λ꜀ and EAL of 26 case-study steel BRBF buildings (designed in accordance with TS 1170.5) is examined. Hazard-consistent λ꜀ and EAL for these buildings are estimated using the FEMA P-58 loss and risk assessment framework. Among the 26 case-study buildings, 23 satisfy the maximum code-specified λ꜀ limit of 10−⁴. The EAL, normalised by the total building replacement cost, is highest for 2-storey BRBFs (0.22% on average), followed by 4-storey BRBFs (0.16% on average) and 8-storey BRBFs (0.11% on average). Reducing the design drift limit has the most significant effect on lowering λ꜀ (all BRBF designs were drift governed), followed by transitioning from pinned to moment-resisting beam-column connections, reducing the brace angle, and increasing brace strength. BRBF buildings designed using the equivalent lateral force method, on average, have a lower λ꜀ compared to those designed using the modal response spectrum method. Diagonally configured BRBFs exhibit the lowest λ꜀, followed by super- X and chevron configured BRBFs. Most design variables, apart from drift limit and beam-column connection, have limited influence on EAL. A simple method for EDP-targeted design of steel BRBF buildings is proposed. For this purpose, linear regression and CatBoost machine learning models are developed to predict steel BRBF building EDPs using peak storey drift ratio (PSDR) and PFA estimates from the 26 case-study buildings at intensity levels ranging from 80% to 0.5% probability of exceedance in 50 years. The R²ₐₔⱼ of these models is around 0.98, while the average prediction error is less than 10%. Fundamental period (T₁), total building height (Hₜ), and pseudospectral acceleration at T₁, denoted as Sₐ(T₁), are selected as the features to predict PSDR, while T₁, Hₜ, and PGA are the features selected to predict PFA. The EDP-targeted design has three steps: (i) for a given Hₜ value, the PSDR prediction model is used to identify a suitable T₁ that can achieve a desired PSDR target at the design intensity, (ii) a force-based design is then conducted iteratively to achieve the target T₁ by using an appropriate ductility factor and design drift limit, and (iii) based on the T₁ in the final design iteration, the PFA demand estimated by the PFA prediction models is used as a conservative input for the design of acceleration-sensitive non-structural elements. An equation to predict λ꜀ at the design stage is proposed for collapse risk-targeted seismic design of buildings. This equation comprises three principal components: reserve building strength, a proxy for effective structural stiffness, and reserve building deformation capacity. This equation is calibrated for the collapse risk-targeted design of BRBF buildings in New Zealand using results from 26 case-study BRBF buildings. The validity of this equation is demonstrated with three design verification examples designed to specific λ꜀ targets. Considering λ꜀ from hazard-consistent incremental dynamic analysis as the benchmark, the mean absolute percentage error in the design-stage prediction of λ꜀ of the verification buildings is approximately 10%.