International Journal of Architectural Heritage, Sep 22, 2016
N.B. Using a real DOI will form a link to the Version of Record on Taylor & Francis Online. The A... more N.B. Using a real DOI will form a link to the Version of Record on Taylor & Francis Online. The AM is defined by the National Information Standards Organization as: "The version of a journal article that has been accepted for publication in a journal." This means the version that has been through peer review and been accepted by a journal editor. When you receive the acceptance email from the Editorial Office we recommend that you retain this article for future posting. Embargoes apply if you are posting the AM to an institutional or subject repository, or to academic social networks such as Mendeley, ResearchGate, or Academia.edu.
Earthquake Engineering & Structural Dynamics, Oct 22, 2015
selfarchived immediately on acceptance of the article. The version posted must acknowledge accept... more selfarchived immediately on acceptance of the article. The version posted must acknowledge acceptance for publication and, following the final publication, include the following notice on the first page: "This is the pre-peer reviewed version of the following article: [FULL CITE], which has been published in final form at [Link to final article using the DOI]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."
Investigation of equivalent frame modelling for seismic analysis of unreinforced masonry building... more Investigation of equivalent frame modelling for seismic analysis of unreinforced masonry buildings with flexible diaphragms Mechanics of Structures and Materials XXIV: Proceedings of the 24th Australian Conference on the Mechanics of Structures and Materials, 2016 / Hao, H., Zhang, C. (ed./s), pp.459-464
The non-structural components in buildings are often subject to greater earthquake accelerations ... more The non-structural components in buildings are often subject to greater earthquake accelerations than that of the ground. This acceleration amplification is due to the building’smain lateral resisting system being subject to additional ‘relative’ accelerations as they deform when subjected to ground motion. Floor accelerations can be conservatively estimated using linear dynamic analysis, however even relatively simple modal analysis for buildings with flexible floor(s)/roof is often impractical. A simple modal analysis is proposed that is based upon the assumption of two vibration modes for the buildings, one being the first building mode if the diaphragm vibrations are excluded and the other being a diaphragm-related mode. These modal properties are simple to calculate and the results from the proposed method has practical value. For the evaluation of the method, parametric nonlinear time-history analyses were conducted on four building typologies with diaphragm flexibility being ...
Professor Griffith will give an overview of recent and ongoing research into the seismic behaviou... more Professor Griffith will give an overview of recent and ongoing research into the seismic behaviour of unreinforced masonry (URM) construction in Australia. His talk will focus primarily on: - the seismic vulnerability of URM walls to out-of-plane bending and the associated local failure mechanisms; - the influence of flexible floor and roof diaphragms on the seismic response of URM buildings up the height and the impact on non-structural components; and - a progress report on work studying the seismic resistance of Heritage URM (stone and brick) construction.
Building typologies and possible macroelements Macroelements Triangular top of the façade overtur... more Building typologies and possible macroelements Macroelements Triangular top of the façade overturning. F macroelement. Corner overturning. CO macroelement. Mixed overturning. F and CO macroelements.
The historic precincts of suburban cities in New Zealand are characterised by partially occupied,... more The historic precincts of suburban cities in New Zealand are characterised by partially occupied, vacant or abandoned buildings, which are located in key locations of the central business districts (CBDs). Increasing unoccupied spaces and low demand for older buildings are detrimental to the socio-economic growth of many provincial towns in New Zealand. The study discussed in this paper sought to: 1) investigate the proportion of totally/partially existing vacant older buildings within the town centre of suburb-#; 2) identify the underlying factors that contributed to emergence of the vacant buildings and the consequences of the prevalent vacancy rate on suburban town centres; and 3) recommend possible ways to increase the demand for these buildings. Using a mixed-methods approach for data collection, the research findings showed a vacancy rate of approximately 86 per cent (n = 47) of older heritage buildings located in the main high street of suburb-#. Additionally, several factors...
The study of unreinforced masonry buildings and their performance in earthquakes is a topic that ... more The study of unreinforced masonry buildings and their performance in earthquakes is a topic that has led to strong Australasian collaboration amongst masonry researchers over the last decade, that has resulted in significant advances in knowledge and empirical evidence, comprehensive capture of post-earthquake "perishable data", the development of new numerical assessment and design procedures, and the training of a new generation of masonry researchers. These efforts have significantly influenced national policy and professional practice, particularly in New Zealand. A chronology of these events is reported.
Bulletin of the New Zealand Society for Earthquake Engineering, 2015
The Global Earthquake Model’s (GEM) Earthquake Consequences Database (GEMECD) aims to develop, fo... more The Global Earthquake Model’s (GEM) Earthquake Consequences Database (GEMECD) aims to develop, for the first time, a standardised framework for collecting and collating geocoded consequence data induced by primary and secondary seismic hazards to different types of buildings, critical facilities, infrastructure and population, and relate this data to estimated ground motion intensity via the USGS ShakeMap Atlas. New Zealand is a partner of the GEMECD consortium and to-date has contributed with 7 events to the database, of which 4 are localised in the South Pacific area (Newcastle 1989; Luzon 1990; South of Java 2006 and Samoa Islands 2009) and 3 are NZ-specific events (Edgecumbe 1987; Darfield 2010 and Christchurch 2011). This contribution to GEMECD represented a unique opportunity for collating, comparing and reviewing existing damage datasets and harmonising them into a common, openly accessible and standardised database, from where the seismic performance of New Zealand buildings...
Bulletin of the New Zealand Society for Earthquake Engineering, 2016
A case study was conducted to investigate the applicability of the equivalent frame modelling for... more 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.
While the efficacy of salvaging underutilised historical buildings to promote sustainable and res... more While the efficacy of salvaging underutilised historical buildings to promote sustainable and resilient provincial urban areas in New Zealand has been identified from past studies, there is still an absence of a performancebased framework to rank optimal historical building alternatives for adaptive reuse interventions. This paper focuses on evaluating a performance-based Multiple Criteria Decision Assessment (MCDA) methodology to prioritise underutilised historical buildings for adaptive reuse intervention in a major provincial area in New Zealand, towards achieving a resilient town-centre regeneration for the area. A focus group workshop was conducted with relevant stakeholders involved in an existing town centre regeneration agenda for Whanganui, to explore and balance their opinions for optimal selection of a vacant historical building for adaptive reuse intervention from a group of proposed buildings. The participant mix comprised a combination of building professionals, historical building owners/developers/users, legal, heritage, and council/community representatives. The findings establish the usefulness of the validated framework in balancing the diverse interests of all stakeholders in the adaptive reuse decision-making process. Hence, this paper provides a significant contribution to the development of a methodology that integrates adaptive reuse stakeholders' diversified interests, for the selection of optimal case study building alternatives. The consensus of the multidisciplinary stakeholder group was found to be consistent and insensitive to reasonable changes in weighting. Also, the validated framework enabled the decision-makers to achieve a logical result, and support the visualisation of the impact of different priority aspects and criteria on adaptive reuse interventions in New Zealand.
The strength and deformability of reinforced concrete (RC) structures strengthened with externall... more The strength and deformability of reinforced concrete (RC) structures strengthened with externally bonded fibrereinforced polymer (FRP) composites can be enhanced with the addition of anchorage devices. The inclusion of anchorage can also result in a higher utilization of the desirable strength properties of the FRP by mitigating debonding. FRP spike anchors are a particularly effective type of anchorage devices as they can be applied to a wide variety of structural forms that have been strengthened with FRP composites. Experimental verification has supported the effectiveness of such anchors. However, the limited availability of design guidance is inhibiting the widespread application of anchors in practice. A critical review of the design models available in the literature is presented in addition to a design methodology for the incorporation of FRP spike anchors in RC structures strengthened with FRP composites. Exemplar designs of FRP spike anchors are also presented, to be used in combination with the design examples currently included in ACI 440.2R (2017). Finally, several knowledge gaps are identified which can be used to inform future studies.
International Journal of Building Pathology and Adaptation, 2018
Purpose Most provincial town centres in New Zealand typically feature old and vacant historical b... more Purpose 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. Design/methodology/approach A focus group workshop was conducted with 22 stakeholders involved in an existing town centre regeneration ag...
In this paper, an experimental study has been conducted on strengthening of reinforced concrete (... more In this paper, an experimental study has been conducted on strengthening of reinforced concrete (RC) connections by FRP sheets. The innovation of this research is using narrow grooves on critical regions of connection to increase the adherence of FRP sheets and prevent their early debonding. Therefore, four RC connections were made and tested under a constant axial load on the column and an increasing cyclic load on the beam. The first specimen, as the standard reference specimen, had close tie spacing in ductile regions of beam, column and panel zone based on seismic design provisions, and the second specimen, as the weak reference specimen did not have these conditions in all regions. Two other weak specimens were strengthened using two different strengthening patterns with FRP sheets; one by ordinary surface preparation and the other with surface grooving method for installing FRP sheets on the connection. The results showed that ultimate load and ductility of the weak specimen compared to standard specimen decreased 25% and 17%, respectively. The shear failure and concrete crushing were prevented in the ductile regions of the beam and panel zone in both strengthened specimens. Also, it was observed that early debonding of FRP sheets was prevented in the strengthened connection with grooving pattern and so had desirable ductility and bearing capacity similar to the standard specimen.
A self-centering concrete wall system has been developed that consists of a Precast Wall with End... more A self-centering concrete wall system has been developed that consists of a Precast Wall with End Columns (PreWEC). A finite element model was developed to investigate the cyclic lateral-load response of the PreWEC system that included allowance for uplift at the wall-to-foundation interface, inclusion of the energy dissipating O-connectors, and inelastic behaviour of the confined concrete in the toe of the wall. The model showed good correlation with the results of a large-scale experimental test of the PreWEC system for both the global and local responses, closely matched the experimental lateral forcedisplacement response, unbonded tendon stress, neutral axis depth, concrete compressive strains, and connector deformation. Additional analyses were conducted to investigate modifications to the PreWEC design. These modified designs highlighted the influence of the inelastic behaviour of the wall toe and showed that in the PreWEC system the axial load on the wall panel is independent of the number of energy dissipating connectors. Lastly, analyses were conducted to investigate wall-to-floor interaction with the PreWEC system. It was shown that a rigid wall-to-floor connection would result in some damage to the floor diaphragms and an overstrength that should be considered when designing the wall for shear. Alternatively, connectors could be used with the PreWEC system to isolate the floor from the uplift of the wall and eliminate damage to the floor diaphragm.
A review of the available procedures and guidelines for the in-plane assessment of existing timbe... more A review of the available procedures and guidelines for the in-plane assessment of existing timber diaphragms in unreinforced masonry (URM) buildings is provided. Most of the provisions that concern flexible wood floors and that are valid for URM, can as a matter of fact be adopted for historic masonry buildings reinforced with timber frames. Recommendations from the most recent international standards like ASCE 41-13 and NZSEE 2015 were thoroughly analysed. Particular attention was given to producing a step-by-step practice-oriented guideline that provides background information which helps understand better the procedure frame work and also gives suggestions for alternative interpretations when multiple choices are possible.
International Journal of Architectural Heritage, Sep 22, 2016
N.B. Using a real DOI will form a link to the Version of Record on Taylor & Francis Online. The A... more N.B. Using a real DOI will form a link to the Version of Record on Taylor & Francis Online. The AM is defined by the National Information Standards Organization as: "The version of a journal article that has been accepted for publication in a journal." This means the version that has been through peer review and been accepted by a journal editor. When you receive the acceptance email from the Editorial Office we recommend that you retain this article for future posting. Embargoes apply if you are posting the AM to an institutional or subject repository, or to academic social networks such as Mendeley, ResearchGate, or Academia.edu.
Earthquake Engineering & Structural Dynamics, Oct 22, 2015
selfarchived immediately on acceptance of the article. The version posted must acknowledge accept... more selfarchived immediately on acceptance of the article. The version posted must acknowledge acceptance for publication and, following the final publication, include the following notice on the first page: "This is the pre-peer reviewed version of the following article: [FULL CITE], which has been published in final form at [Link to final article using the DOI]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."
Investigation of equivalent frame modelling for seismic analysis of unreinforced masonry building... more Investigation of equivalent frame modelling for seismic analysis of unreinforced masonry buildings with flexible diaphragms Mechanics of Structures and Materials XXIV: Proceedings of the 24th Australian Conference on the Mechanics of Structures and Materials, 2016 / Hao, H., Zhang, C. (ed./s), pp.459-464
The non-structural components in buildings are often subject to greater earthquake accelerations ... more The non-structural components in buildings are often subject to greater earthquake accelerations than that of the ground. This acceleration amplification is due to the building’smain lateral resisting system being subject to additional ‘relative’ accelerations as they deform when subjected to ground motion. Floor accelerations can be conservatively estimated using linear dynamic analysis, however even relatively simple modal analysis for buildings with flexible floor(s)/roof is often impractical. A simple modal analysis is proposed that is based upon the assumption of two vibration modes for the buildings, one being the first building mode if the diaphragm vibrations are excluded and the other being a diaphragm-related mode. These modal properties are simple to calculate and the results from the proposed method has practical value. For the evaluation of the method, parametric nonlinear time-history analyses were conducted on four building typologies with diaphragm flexibility being ...
Professor Griffith will give an overview of recent and ongoing research into the seismic behaviou... more Professor Griffith will give an overview of recent and ongoing research into the seismic behaviour of unreinforced masonry (URM) construction in Australia. His talk will focus primarily on: - the seismic vulnerability of URM walls to out-of-plane bending and the associated local failure mechanisms; - the influence of flexible floor and roof diaphragms on the seismic response of URM buildings up the height and the impact on non-structural components; and - a progress report on work studying the seismic resistance of Heritage URM (stone and brick) construction.
Building typologies and possible macroelements Macroelements Triangular top of the façade overtur... more Building typologies and possible macroelements Macroelements Triangular top of the façade overturning. F macroelement. Corner overturning. CO macroelement. Mixed overturning. F and CO macroelements.
The historic precincts of suburban cities in New Zealand are characterised by partially occupied,... more The historic precincts of suburban cities in New Zealand are characterised by partially occupied, vacant or abandoned buildings, which are located in key locations of the central business districts (CBDs). Increasing unoccupied spaces and low demand for older buildings are detrimental to the socio-economic growth of many provincial towns in New Zealand. The study discussed in this paper sought to: 1) investigate the proportion of totally/partially existing vacant older buildings within the town centre of suburb-#; 2) identify the underlying factors that contributed to emergence of the vacant buildings and the consequences of the prevalent vacancy rate on suburban town centres; and 3) recommend possible ways to increase the demand for these buildings. Using a mixed-methods approach for data collection, the research findings showed a vacancy rate of approximately 86 per cent (n = 47) of older heritage buildings located in the main high street of suburb-#. Additionally, several factors...
The study of unreinforced masonry buildings and their performance in earthquakes is a topic that ... more The study of unreinforced masonry buildings and their performance in earthquakes is a topic that has led to strong Australasian collaboration amongst masonry researchers over the last decade, that has resulted in significant advances in knowledge and empirical evidence, comprehensive capture of post-earthquake "perishable data", the development of new numerical assessment and design procedures, and the training of a new generation of masonry researchers. These efforts have significantly influenced national policy and professional practice, particularly in New Zealand. A chronology of these events is reported.
Bulletin of the New Zealand Society for Earthquake Engineering, 2015
The Global Earthquake Model’s (GEM) Earthquake Consequences Database (GEMECD) aims to develop, fo... more The Global Earthquake Model’s (GEM) Earthquake Consequences Database (GEMECD) aims to develop, for the first time, a standardised framework for collecting and collating geocoded consequence data induced by primary and secondary seismic hazards to different types of buildings, critical facilities, infrastructure and population, and relate this data to estimated ground motion intensity via the USGS ShakeMap Atlas. New Zealand is a partner of the GEMECD consortium and to-date has contributed with 7 events to the database, of which 4 are localised in the South Pacific area (Newcastle 1989; Luzon 1990; South of Java 2006 and Samoa Islands 2009) and 3 are NZ-specific events (Edgecumbe 1987; Darfield 2010 and Christchurch 2011). This contribution to GEMECD represented a unique opportunity for collating, comparing and reviewing existing damage datasets and harmonising them into a common, openly accessible and standardised database, from where the seismic performance of New Zealand buildings...
Bulletin of the New Zealand Society for Earthquake Engineering, 2016
A case study was conducted to investigate the applicability of the equivalent frame modelling for... more 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.
While the efficacy of salvaging underutilised historical buildings to promote sustainable and res... more While the efficacy of salvaging underutilised historical buildings to promote sustainable and resilient provincial urban areas in New Zealand has been identified from past studies, there is still an absence of a performancebased framework to rank optimal historical building alternatives for adaptive reuse interventions. This paper focuses on evaluating a performance-based Multiple Criteria Decision Assessment (MCDA) methodology to prioritise underutilised historical buildings for adaptive reuse intervention in a major provincial area in New Zealand, towards achieving a resilient town-centre regeneration for the area. A focus group workshop was conducted with relevant stakeholders involved in an existing town centre regeneration agenda for Whanganui, to explore and balance their opinions for optimal selection of a vacant historical building for adaptive reuse intervention from a group of proposed buildings. The participant mix comprised a combination of building professionals, historical building owners/developers/users, legal, heritage, and council/community representatives. The findings establish the usefulness of the validated framework in balancing the diverse interests of all stakeholders in the adaptive reuse decision-making process. Hence, this paper provides a significant contribution to the development of a methodology that integrates adaptive reuse stakeholders' diversified interests, for the selection of optimal case study building alternatives. The consensus of the multidisciplinary stakeholder group was found to be consistent and insensitive to reasonable changes in weighting. Also, the validated framework enabled the decision-makers to achieve a logical result, and support the visualisation of the impact of different priority aspects and criteria on adaptive reuse interventions in New Zealand.
The strength and deformability of reinforced concrete (RC) structures strengthened with externall... more The strength and deformability of reinforced concrete (RC) structures strengthened with externally bonded fibrereinforced polymer (FRP) composites can be enhanced with the addition of anchorage devices. The inclusion of anchorage can also result in a higher utilization of the desirable strength properties of the FRP by mitigating debonding. FRP spike anchors are a particularly effective type of anchorage devices as they can be applied to a wide variety of structural forms that have been strengthened with FRP composites. Experimental verification has supported the effectiveness of such anchors. However, the limited availability of design guidance is inhibiting the widespread application of anchors in practice. A critical review of the design models available in the literature is presented in addition to a design methodology for the incorporation of FRP spike anchors in RC structures strengthened with FRP composites. Exemplar designs of FRP spike anchors are also presented, to be used in combination with the design examples currently included in ACI 440.2R (2017). Finally, several knowledge gaps are identified which can be used to inform future studies.
International Journal of Building Pathology and Adaptation, 2018
Purpose Most provincial town centres in New Zealand typically feature old and vacant historical b... more Purpose 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. Design/methodology/approach A focus group workshop was conducted with 22 stakeholders involved in an existing town centre regeneration ag...
In this paper, an experimental study has been conducted on strengthening of reinforced concrete (... more In this paper, an experimental study has been conducted on strengthening of reinforced concrete (RC) connections by FRP sheets. The innovation of this research is using narrow grooves on critical regions of connection to increase the adherence of FRP sheets and prevent their early debonding. Therefore, four RC connections were made and tested under a constant axial load on the column and an increasing cyclic load on the beam. The first specimen, as the standard reference specimen, had close tie spacing in ductile regions of beam, column and panel zone based on seismic design provisions, and the second specimen, as the weak reference specimen did not have these conditions in all regions. Two other weak specimens were strengthened using two different strengthening patterns with FRP sheets; one by ordinary surface preparation and the other with surface grooving method for installing FRP sheets on the connection. The results showed that ultimate load and ductility of the weak specimen compared to standard specimen decreased 25% and 17%, respectively. The shear failure and concrete crushing were prevented in the ductile regions of the beam and panel zone in both strengthened specimens. Also, it was observed that early debonding of FRP sheets was prevented in the strengthened connection with grooving pattern and so had desirable ductility and bearing capacity similar to the standard specimen.
A self-centering concrete wall system has been developed that consists of a Precast Wall with End... more A self-centering concrete wall system has been developed that consists of a Precast Wall with End Columns (PreWEC). A finite element model was developed to investigate the cyclic lateral-load response of the PreWEC system that included allowance for uplift at the wall-to-foundation interface, inclusion of the energy dissipating O-connectors, and inelastic behaviour of the confined concrete in the toe of the wall. The model showed good correlation with the results of a large-scale experimental test of the PreWEC system for both the global and local responses, closely matched the experimental lateral forcedisplacement response, unbonded tendon stress, neutral axis depth, concrete compressive strains, and connector deformation. Additional analyses were conducted to investigate modifications to the PreWEC design. These modified designs highlighted the influence of the inelastic behaviour of the wall toe and showed that in the PreWEC system the axial load on the wall panel is independent of the number of energy dissipating connectors. Lastly, analyses were conducted to investigate wall-to-floor interaction with the PreWEC system. It was shown that a rigid wall-to-floor connection would result in some damage to the floor diaphragms and an overstrength that should be considered when designing the wall for shear. Alternatively, connectors could be used with the PreWEC system to isolate the floor from the uplift of the wall and eliminate damage to the floor diaphragm.
A review of the available procedures and guidelines for the in-plane assessment of existing timbe... more A review of the available procedures and guidelines for the in-plane assessment of existing timber diaphragms in unreinforced masonry (URM) buildings is provided. Most of the provisions that concern flexible wood floors and that are valid for URM, can as a matter of fact be adopted for historic masonry buildings reinforced with timber frames. Recommendations from the most recent international standards like ASCE 41-13 and NZSEE 2015 were thoroughly analysed. Particular attention was given to producing a step-by-step practice-oriented guideline that provides background information which helps understand better the procedure frame work and also gives suggestions for alternative interpretations when multiple choices are possible.
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Papers by Jason M Ingham