ORCID Profile
0000-0002-0989-9097
Current Organisation
The University of Auckland
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Informa UK Limited
Date: 10-02-2021
Publisher: Informa UK Limited
Date: 26-01-2020
Publisher: New Zealand Society for Earthquake Engineering
Date: 30-09-2016
DOI: 10.5459/BNZSEE.49.3.234-244
Abstract: A case study was conducted to investigate the applicability of the equivalent frame modelling for the nonlinear time-history analysis of unreinforced masonry buildings with flexible diaphragms. The dynamic responses calculated from the equivalent frame models were compared against shake table test results of a full-scale two-storey stone masonry building. The investigated modelling approach reflected the simplifications commonly assumed for the global analysis of buildings namely, considering the diaphragms to behave elastically and neglecting the stiffness and strength contributions of the out-of-plane responding walls. The sensitivity of the analysis to different idealisations of the equivalent frame, as well as to the diaphragm stiffness values, were also investigated. Discussions are provided on the accuracies and limitations of the investigated modelling approach, which may serve as a useful guidance for practical application.
Publisher: American Society of Civil Engineers (ASCE)
Date: 04-2013
Publisher: Emerald
Date: 04-11-2014
Abstract: – The purpose of this paper is to examine why building owners are often reluctant to adopt adequate mitigation measures despite the vulnerability of their buildings to earthquake disasters, by exploring the economic-related barriers to earthquake mitigation decisions. – A case study research method was adopted and interviews chosen as the method of data collection. – Critical economic-related impediments that inhibited seismic retrofitting of earthquake-prone buildings were revealed in this study. Economic-related barriers identified include perception about financial involvement in retrofitting, property market conditions, high insurance premiums and deductibles, and the high cost of retrofitting. The availability of financial incentives such as low interest loans, tax deductibles, the implementation of a risk-based insurance premium scale and promoting increased knowledge and awareness of seismic risks and mitigation measures in the property market place are likely to address the economic-related challenges faced by property owners when undertaking seismic retrofitting projects. The provision of financial incentives specifically for seismic retrofitting should be introduced in policy-implementation programme tailored to local governments’ level of risks exposure and available resources. – The recommendations provided in this study suggest strategies and answers to questions aimed at understanding the types of incentives that city councils and environmental hazard managers should focus on in their attempt to ensure that property owners actively participate in earthquake risk mitigation. – This paper adopts a holistic perspective for investigating earthquake risk mitigation by examining the opinions of the different stakeholders involved in seismic retrofit decisions.
Publisher: Inderscience Publishers
Date: 2011
Publisher: New Zealand Society for Earthquake Engineering
Date: 30-06-2014
DOI: 10.5459/BNZSEE.47.2.97-118
Abstract: Currently there is little guidance available on an experimentally-validated detailed seismic assessment procedure for vintage flexible timber diaphragms such as are routinely encountered in New Zealand unreinforced masonry buildings. The results from recent testing of full-scale diaphragms are presented and interpreted with particular attention given to the definition of shear stiffness and shear strength values, whilst acknowledging that the recommendations derive from a small data set. References are provided to information previously published elsewhere to justify the theoretical framework adopted, and the procedure is linked to ASCE 41-13 for guidance regarding diaphragm scenarios that have not been studied by the authors. A procedure is provided to account for the effects on diaphragm response of supplementary stiffness due to masonry end walls. The performance of several diaphragms that were improved with either overlays or underlays is reported as potential proof-tested standard solutions. The assessment procedure is demonstrated by providing a mock worked ex le of a detailed diaphragm assessment.
Publisher: Informa UK Limited
Date: 22-09-2016
Publisher: American Society of Civil Engineers (ASCE)
Date: 11-2017
Publisher: American Society of Civil Engineers (ASCE)
Date: 05-2014
Publisher: American Society of Civil Engineers (ASCE)
Date: 08-2014
Publisher: Wiley
Date: 22-10-2015
DOI: 10.1002/EQE.2671
Publisher: New Zealand Society for Earthquake Engineering
Date: 30-06-2014
DOI: 10.5459/BNZSEE.47.2.119-138
Abstract: A procedure is proposed to evaluate the dynamic out-of-plane stability of cracked unreinforced masonry (URM) walls located in multi-storey URM buildings. The equations of dynamic motion are derived from first principles and representative single-degree-of-freedom (SDOF) models are proposed. The models have nonlinear stiffness properties that correspond to the restoring gravitational forces. A method is suggested to transform the nonlinear problem to a corresponding linear equivalent so that conventional spectral methods can be used to calculate wall response. The dynamic interaction between the URM building as the main structural system and the out-of-plane loaded walls as secondary elements is addressed by developing floor response spectra. Several buildings were assumed in a parametric study and subjected to code-compatible ground motion records. The absolute acceleration response at floor levels was calculated and the response spectra for that modified acceleration were subsequently obtained. The results from the study suggest that modifications should be made to the equations proposed for the Parts response spectra in the New Zealand seismic loading standard, NZS 1170.5:2004, in order to calculate the spectral response of out-of-plane loaded URM walls. Several worked ex les are presented to demonstrate application of the procedure.
Publisher: Elsevier BV
Date: 08-2018
Publisher: Informa UK Limited
Date: 24-08-2023
Publisher: Elsevier BV
Date: 08-2015
Publisher: Informa UK Limited
Date: 08-2013
Publisher: New Zealand Society for Earthquake Engineering
Date: 31-12-2018
DOI: 10.5459/BNZSEE.51.4.171-182
Abstract: Small to Medium-sized Enterprises (SMEs) are often vulnerable to the adversities caused by major earthquake events, which may include business disruption, damage to goods and property, impaired employee health and safety, financial strain and loss of revenue, or even total loss of the business. SMEs are expected to make critical decisions to prepare their businesses for an earthquake, in an attempt to ensure business continuity and the wellbeing of their employees, should a disaster occur. This study was conducted five years after the devastating Canterbury earthquakes and sought to examine the level of earthquake preparedness of SMEs by investigating the actions undertaken in two different suburban locations having differing seismicity. The extent of preparedness was assessed based on a list of twenty-one possible actions grouped into four categories being knowledge enrichment, insurance and business continuity, survival support actions, and seismic damage mitigation. The assessment involved a survey with an online questionnaire. Analysis of the collected data revealed a specific adoption pattern in the regions of study. The main preparedness action adopted by SMEs was the purchase of business insurance with the development of continuity plans. The least obtained preparedness action was related to survival support actions such as maintaining necessary emergency supplies. The overall adoption rate of the preparedness actions was less than 30%, with no significant difference between the regions studied, and close to 50% of SMEs having adopted less than five preparedness actions. This situation clearly requires urgent attention from all stakeholders involved in SMEs resilience before an earthquake disaster hits the regions.
Publisher: Informa UK Limited
Date: 16-08-2013
Publisher: New Zealand Society for Earthquake Engineering
Date: 31-12-2014
DOI: 10.5459/BNZSEE.47.4.275-289
Abstract: It is well recognised that the dynamic response of unreinforced masonry buildings with flexible timber diaphragms typically contains multiple dominant modes associated with the excitations of the diaphragms and the in-plane walls. Existing linear analysis methods for this type of structure commonly account for the multi-mode behaviour by assuming the independent vibrations of the in-plane loaded walls (in-plane walls) and the diaphragms. Specifically, the in-plane walls are considered to be rigid and the unmodified ground motion is assumed to be transmitted up the walls to the diaphragm ends. While this assumption may be appropriate for many low-rise unreinforced masonry buildings, neglecting the dynamic interaction between the diaphragms and the in-plane walls can lead to unreliable predictions of seismic demands. An alternative analysis approach is proposed in this paper, based on the mode properties of a system in which (1) the mass ratios between the diaphragms and the in-plane wall are the same at all levels, and (2) the periods of the diaphragms are the same at all levels. It is proposed that under these conditions, two modes are typically sufficient to obtain the peak seismic demands of the in-plane walls in elastically responding low-rise regular buildings. The applicability of the two-mode analysis approach is assessed for more general diaphragm configurations by sensitivity analysis, and the limitations are identified. The two-mode approach is then used to derive a response modification factor, which may be used in conjunction with a linear static procedure in the seismic assessment of buildings with flexible diaphragms.
Publisher: American Society of Civil Engineers (ASCE)
Date: 06-2014
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 08-2018
Publisher: Elsevier BV
Date: 03-2019
Publisher: SAGE Publications
Date: 02-2014
Abstract: The progressive damage and subsequent demolition of unreinforced masonry (URM) buildings arising from the Canterbury earthquake sequence is reported. A dataset was compiled of all URM buildings located within the Christchurch CBD, including information on location, building characteristics, and damage levels after each major earthquake in this sequence. A general description of the overall damage and the hazard to both building occupants and to nearby pedestrians due to debris falling from URM buildings is presented with several case study buildings used to describe the accumulation of damage over the earthquake sequence. The benefit of seismic improvement techniques that had been installed to URM buildings is shown by the reduced damage ratios reported for increased levels of retrofit. Demolition statistics for URM buildings in the Christchurch CBD are also reported and discussed.
Publisher: Elsevier BV
Date: 12-2020
Publisher: SAGE Publications
Date: 2014
DOI: 10.3141/2431-06
Abstract: Flushing is a defect that has a damaging effect on the functional performance of chip seal pavements. The reported study was conducted to develop techniques to identify and assess flushed pavements effectively. The main aims of the study were first to investigate the effects of chip seal volumetrics on development of flushing and second to develop a model to forecast flushing of chip seal pavements. The study methodology consisted of mechanical testing of chip seal pavement s les and analysis of pavement performance data. Laboratory testing was conducted on s les obtained from flushed chip seal pavements from four regions in New Zealand. S les were loaded by using a wheel-tracking device, and imaging techniques were used to assess the effects of micromechanical changes on development of flushing. Data analysis was performed on pavement condition data to identify factors providing the best prediction of flushing, and regression analysis was performed to develop a model to predict the initiation and progression of flushing. Study results revealed a direct relationship between flushing and reduction in air void volume that occurred as a result of loading. Data analysis revealed that the combination of factors providing the best indication of flushing was surface thickness, surface age, rut depth, and grade of aggregates. The flushing initiation model had an accuracy of 76%, and the flushing progression model was robust at predicting the quantity of flushing. By using the study outcomes, a pavement condition assessment guideline was developed to aid with assessing and managing flushed chip seal pavements.
Publisher: New Zealand Society for Earthquake Engineering
Date: 31-12-2011
DOI: 10.5459/BNZSEE.44.4.279-296
Abstract: As part of the ‘Project Masonry’ Recovery Project funded by the New Zealand Natural Hazards Research Platform, commencing in March 2011, an international team of researchers was deployed to document and interpret the observed earthquake damage to masonry buildings and to churches as a result of the 22nd February 2011 Christchurch earthquake. The study focused on investigating commonly encountered failure patterns and collapse mechanisms. A brief summary of activities undertaken is presented, detailing the observations that were made on the performance of and the deficiencies that contributed to the damage to approximately 650 inspected unreinforced clay brick masonry (URM) buildings, to 90 unreinforced stone masonry buildings, to 342 reinforced concrete masonry (RCM) buildings, to 112 churches in the Canterbury region, and to just under 1100 residential dwellings having external masonry veneer cladding. In addition, details are provided of retrofit techniques that were implemented within relevant Christchurch URM buildings prior to the 22nd February earthquake and brief suggestions are provided regarding appropriate seismic retrofit and remediation techniques for stone masonry buildings.
Publisher: New Zealand Society for Earthquake Engineering
Date: 30-06-2014
DOI: 10.5459/BNZSEE.47.2.139-156
Abstract: The 2010-2011 Canterbury earthquakes and corresponding Royal Commission reports have resulted in changes to the legislative environment and led to increased public awareness in New Zealand of the earthquake performance of unreinforced masonry (URM) buildings. As a result, building regulators, owners, tenants, users and heritage stakeholders will be facing a unique challenge in the near future where assessments, improvements and demolitions of URM buildings are expected to occur at an unusually high rate. Auckland is the largest city in New Zealand and because of the relative prosperity of Auckland during the period 1880-1935 when most URM buildings were being constructed in New Zealand, the city has the largest number of URM buildings in the country. Identifying those buildings most at seismic risk in Auckland’s large and varied building stock has warranted a rapid field assessment program supplemented by strategically chosen detailed assessments. Information that can be procured through rapid field inspections includes the building geometric typologies (e.g., heights, building footprint geometry and isolated versus row configuration), elevation type (e.g., perforated frame versus solid wall), wall construction (e.g., solid versus cavity, number of leaves) and basic construction material type (e.g., clay brick versus stone). Furthermore, investigation into the architectural history, heritage status and functional usage of Auckland’s URM buildings will affect the direction of retrofit strategies and priorities. As the owner of a large and varied portfolio of URM buildings as well as the local organisation responsible for assessing building safety, Auckland Council is developing exemplar inspection, assessment, prioritisation and retrofit strategies that will target the seismic risks associated with URM buildings, in particular, so as to preserve and enhance safety and the economic and community value of these special buildings. Collaboration amongst Auckland Council, The University of Auckland and GNS Science has resulted in a state-of-the-art rapid quantitative assessment program applied to a s ling of typologically representative URM buildings in Auckland.
Publisher: Informa UK Limited
Date: 06-2011
Publisher: Emerald
Date: 21-08-2018
DOI: 10.1108/IJBPA-01-2018-0007
Abstract: Most provincial town centres in New Zealand typically feature old and vacant historical buildings, the majority of which possess heritage values. The growing perception that it is cheaper to repurpose vacant historical buildings rather than demolishing and rebuilding them is one of the factors that have made the adaptive reuse approach so popular. However, will this also be the case for provincial town centres in New Zealand? The purpose of this paper is to identify and explore the key factors that could influence the efficacy of adaptive reuse, and check for significant differences in the effect that each perceived factor would have on the adaptive reuse efficacy as a justifiable resilient and sustainable approach towards the regeneration of a major provincial town centre in New Zealand that is currently experiencing inner-city shrinkage. A focus group workshop was conducted with 22 stakeholders involved in an existing town centre regeneration agenda for Whanganui. Closed-ended questionnaires were administered to the workshop participants to measure their opinions regarding the efficacy of the adaptive reuse approach for the regeneration of Whanganui’s town centre. The participant mix comprised a combination of structural engineers, quantity surveyors, architects, estate valuers, building owners/developers, legal representatives, heritage representatives and local government council representatives. The study reported a high proportion of respondents that strongly agreed to the positive impacts of adaptive reuse with regards to the discussed priority aspects, hence, justifying the efficacy of the approach, towards delivering a vibrant town centre for Whanganui. Also, the Friedman’s analysis suggests that no significant differences existed among all perceived adaptive reuse efficacy criteria by the workshop participants, therefore justifying the approach. This paper’s originality pertains to the practicality of changing the use of vacant historical buildings in Whanganui, which is one of New Zealand’s major provincial town centres, to renegotiate resilience and sustainable urban regeneration for the area.
Publisher: American Society of Civil Engineers (ASCE)
Date: 05-2012
Publisher: International Journal of Construction Supply Chain Management
Date: 31-12-2015
DOI: 10.14424/IJCSCM502015-34-51
Abstract: The increasing scale of losses from earthquake disasters has reinforced the need for property owners to become proactive in seismic risk reduction programs. However, despite advancement in seismic design methods and legislative frameworks, building owners are found unwilling or lack motivation to adopt adequate mitigation measures that will reduce their vulnerability to earthquake disasters. Various theories and empirical findings have been used to explain the adoption of protective behaviours including seismic mitigation decisions, but their application has been inadequate to enhance building owners’ protective decisions. A holistic framework that incorporates the motivational orientations of decision-making, coupled with the social, cultural, economic, regulatory, institutional and political realms of earthquake risk mitigation to enhance building owners’ decisions to voluntarily implement adequate mitigation measures, is proposed. This framework attempts to address any multi-disciplinary barriers that exist in earthquake disaster management, by ensuring that stakeholders involved in seismic mitigation decisions work together to foster seismic rehabilitation of EPBs, as well as illuminate strategies that will initiate, promote and sustain the adoption of long-term earthquake mitigation.
Publisher: Elsevier BV
Date: 12-2013
Location: United States of America
No related grants have been discovered for Jason Ingham.