324 results for Ingham, Jason

  • A Case Study of Successful Performance of Retrofitted Masonry Substations

    Misnon, Noor Aina; Dizhur, Dmytro; Mackenzie, John; Fikri, Rijalul; Abeling, Shannon; Ingham, Jason (2016)

    Conference Contributions - Other
    University of Canterbury Library

    Since the mid 1990s, the Christchurch inventory of substation buildings was seismically retrofitted as part of the Risk and Realities improvement programme. • The substation buildings were retrofitted using a system of simple and cost-effective steel elements. • The 2010/2011 Canterbury earthquakes caused significant immediate disruption to power distribution network in Christchurch. • It took a single day in September 2010 and ten days in February 2011 to restore power to 90% customers. Tostudytheseismicperformanceofmasonrysubstationbuildingsfromamulti-disciplinary perspective on structural,economic and social aspects.

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  • SEISMIC STRENGTHENING OF REINFORCED CONCRETE COLUMNS WITH STRAIGHT CARBON FIBRE REINFORCED POLYMER (CFRP) ANCHORS

    Ingham, Jason; Griffith, Michael; del Rey Castillo, Enrique (2016)

    Conference Contributions - Other
    University of Canterbury Library

    After consulting key members of the industry (BBR ConTech, Opus International, Fulton Hogan and Beca) it was found that, while the most common failure of RC columns is shear failure, the shear strengthening of RC columns with FRP anchors is fairly well known by engineers, and they are confident in their design. Flexural strengthening of RC columns with FRP anchors is a complex and unknown application and only one example of a research focused on this technique could be found in the existing literature. In addition to verify the applicability of the design equation previously developed, a few aspects not covered in the component tests will be investigated: • The effect of tensile-compression cycles • The effect of dynamic loading • The interaction between adjacent anchors • The behaviour of edge anchors • The effect of overlapped fan components • Behaviour on real case specimen • Effect of different confinement schemes • Effect of different anchor sizes • Strengthening of columns with lap splice failure

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  • Trends in the Architectural Characterisation of Unreinforced Masonry in New Zealand

    Russell, Alistair; Ingham, Jason (2008)

    Conference item
    The University of Auckland Library

    This paper identifies seven typologies for characterising New Zealand???s unreinforced masonry (URM) building stock. This enables a better understanding of what typical behaviour to expect when assessing heritage URM buildings. Distinctions between typologies are drawn largely on the basis of building height and the geometry of the building???s footprint.

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  • Unbonded Prestressed Panel Tendon Stresses at In-Plane Nominal Flexural Strength

    Brooke, Nicholas; Wight, Gavin; Russell, Alistair; Ingham, Jason (2007)

    Conference item
    The University of Auckland Library

    A series of in-plane tests on post-tensioned concrete wall panels with unbonded tendons are described. These tests were used to verify that tendon stresses at nominal flexural strength can be accurately predicted for concrete walls using an equation previously developed for post-tensioned concrete masonry walls. Testing showed that the equation gives more accurate prediction of tendon stress than current design methods used in New Zealand. A secondary objective was to examine the accuracy of ???true??? predictions of wall performance obtained by finite element analysis. Predictions of wall forcedisplacement response, tendon stress increase and concrete strain generally matched experimental data with acceptable accuracy. The experimental response of some walls was significantly influenced by the existence of a bedding layer with low stiffness, which could not be accurately modelled.

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  • Monotonic testing of unreinforced and GFRP-retrofitted masonry walls prone to shear failure in an earthquake

    Mahmood, Hamid; Russell, Alistair; Ingham, Jason (2008)

    Conference item
    The University of Auckland Library

    A research programme has been initiated in New Zealand to address concerns regarding the seismic performance of New Zealand???s unreinforced masonry (URM) building stock. As a component of this programme, monotonic in-plane shear (diagonal compression) tests were conducted on URM wallettes to simulate the commonly observed diagonal shear failure of in-plane walls in an earthquake. In total, four wallettes were tested, three of which were retrofitted with various configurations of GFRP strips. The unretrofitted wallette failed in a brittle manner. The retrofitted wallettes exhibited a more ductile behaviour. Significant increases in wallette strength and pseudo-ductility were achieved by the application of GFRP.

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  • Performance of masonry buildings during the 2010 Darfield (New Zealand) earthquake

    Ismail, N; Griffith, M; Ingham, Jason (2011-06-05)

    Conference item
    The University of Auckland Library

    The M7.1 Darfield earthquake shook the town of Christchurch (New Zealand) in the early morning on Saturday 4th September 2010 and caused damage to a number of heritage unreinforced masonry buildings. No fatalities were reported directly linked to the earthquake, but the damage to important heritage buildings was the most extensive to have occurred since the 1931 Hawke???s Bay earthquake. In general, the nature of damage was consistent with observations previously made on the seismic performance of unreinforced masonry buildings in large earthquakes, with aspects such as toppled chimneys and parapets, failure of gables and poorly secured face-loaded walls, and in-plane damage to masonry frames all being extensively documented. This report on the performance of the unreinforced masonry buildings in the 2010 Darfield earthquake provides details on typical building characteristics, a review of damage statistics obtained by interrogating the building assessment database that was compiled in association with post-earthquake building inspections, and a review of the characteristic failure modes that were observed.

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  • Studies on the material properties of the Aurora Tavern, Auckland

    Lumantarna, R; Dizhur, D; Liu, P; Ingham, Jason (2011-04-14)

    Conference item
    The University of Auckland Library

    The Aurora Tavern was one example of many heritage unreinforced masonry (URM) buildings in New Zealand, and therefore like other existing URM buildings, this hotel was vulnerable to damage should a moderate magnitude earthquake occur. Refurbishment and strengthening work was being implemented on the building, during which in-situ testing was performed to investigate the building???s material properties. The URM materials in the Aurora Tavern were generally in poor condition, and water ingress was observed at various locations in the building. In-situ deformability tests and bed joint shear tests were conducted on-site to determine the masonry stiffness and the mortar bed joint shear strength respectively. In addition, individual brick units and irregular mortar samples were extracted for compression testing in the laboratory. Laboratory mortar compression tests and in-situ deformability tests showed that the mortar compressive strength and masonry Modulus of Elasticity were low. However, the brick compressive and mortar bed joint shear strengths were comparable to those of other buildings that were previously investigated by the research team.

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  • Implications of the 2010 Darfield (Christchurch, NZ) earthquake for Australia ??? are we ready?

    Griffith, MC; Ingham, Jason; Moon, L (2010)

    Conference item
    The University of Auckland Library

    The 2010 Darfield earthquake is the largest earthquake on record to have occurred within 40 km of a major city and not cause any fatalities. In this paper the authors have reflected on their experiences in Christchurch following the earthquake with a view to what worked, what didn???t, and what lessons can be learned from this for the benefit of Australian earthquake preparedness. Owing to the fact that most of the observed building damage occurred in Unreinforced Masonry (URM) construction, this paper focuses in particular on the authors??? experience conducting rapid building damage assessment during the first 72 hours following the earthquake and more detailed examination of the performance of unreinforced masonry buildings with and without seismic retrofit interventions.

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  • Performance of Unreinforced Masonry Structures in the 2010/2011 Canterbury Earthquake Sequence

    Moon, LM; Griffith, MC; Dizhur, Dmytro; Ingham, Jason (2012-09-24)

    Conference item
    The University of Auckland Library

    Following the magnitude 6.3 aftershock in Christchurch, New Zealand, on 22 February 2011, a number of researchers were sent to Christchurch as part of the New Zealand Natural Hazard Research Platform funded ???Project Masonry??? Recovery Project. Their goal was to document and interpret the damage to the masonry buildings and churches in the region. Approximately 650 unreinforced and retrofitted clay brick masonry buildings in the Christchurch area were surveyed for commonly occurring failure patterns and collapse mechanisms. The entire building stock of Christchurch, and in particular the unreinforced masonry building stock, is similar to that in the rest of New Zealand, Australia, and abroad, so the observations made here are relevant for the entire world.

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  • Report on the ???Project Masonry??? recovery project

    Dizhur, D; Ingham, Jason (2012-11-02)

    Conference item
    The University of Auckland Library

    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. Also, details are provided of retrofit techniques that were implemented within relevant Christchurch URM buildings prior to the 22nd February earthquake. In addition to presenting a summary of Project Masonry, the broader research activity at the University of Auckland pertaining to the seismic assessment and improvement of unreinforced masonry buildings is outlined. The purpose of this outline is to provide an overview and bibliography of published literature and to communicate on-going research activity that has not yet been reported in a complete form.

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  • Seismic Performance of Masonry Buildings in the Christchurch Earthquakes 2010-2011: A Progress Report

    Moon, LM; Dizhur, D; Ingham, Jason; Griffith, MC (2012-12-07)

    Conference item
    The University of Auckland Library

    Following the Christchurch earthquake of 22 February 2011 a number of researchers were sent to Christchurch, New Zealand to document the damage to masonry buildings as part of ???Project Masonry???. Coordinated by the Universities of Auckland and Adelaide, researchers came from Australia, New Zealand, Canada, Italy, Portugal and the US. The types of masonry investigated were unreinforced clay brick masonry, unreinforced stone masonry, reinforced concrete masonry, residential masonry veneer and churches; masonry infill was not part of this study. This paper focuses on the progress of the unreinforced masonry (URM) component of Project Masonry. To date the research team has completed raw data collection on over 600 URM buildings in the Christchurch area. The results from this study will be extremely relevant to Australian cities since URM buildings in New Zealand are similar to those in Australia.

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  • Using simplified indices to forecast the seismic vulnerability of New Zealand unreinforced masonry churches

    Ingham, Jason; Lourenco, PB; Leite, J; Castelino, S; Colaco, E (2012-12-07)

    Conference item
    The University of Auckland Library

    Unreinforced masonry churches are particularly vulnerable to earthquakes because they are often deteriorated and damaged, they were built with comparatively low strength materials, they are heavy, and the connections between the various structural components are often insufficient to resist loads generated during earthquakes. A simplified method for seismic assessment of large span masonry churches is presented and data from 44 churches located in Italy, Portugal and Spain are used to provide lower bound limits for different simplified geometrical indexes. Subsequently, the proposed thresholds are validated with data from the 2010-2011 Canterbury earthquakes, including 48 clay brick and stone unreinforced masonry churches. Finally, data collected for 40 unreinforced masonry churches in Wellington and Dunedin are used to identify churches in these cities requiring priority detailed seismic evaluation.

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  • What ductility value should be used when assessing unreinforced masonry buildings

    Allen, C; Masia, M; Derakhshan, H; Griffith, MC; Dizhur, Dmytro; Ingham, Jason (2013-04-26)

    Conference item
    The University of Auckland Library

    There has been much discussion regarding the appropriate values of structural ductility factor, structural performance factor, and equivalent viscous damping coefficient to be used in the assessment of unreinforced masonry (URM) buildings in New Zealand and Australia. The New Zealand Society for Earthquake Engineering 2006 guidelines proposes a ductility factor of 1.0 to be used along with a damping coefficient ratio of 15%. A draft guideline recently developed by researchers from the University of Auckland suggests that a ductility factor of 2.0 and damping ratio of 5% is more suitable. Elsewhere in the world, other researchers have made recommendations regarding these topics. Furthermore, the Canterbury Earthquakes Royal Commission has recently recommended this topic receive further attention. Different alternatives are evaluated by conducting Nonlinear Static (pushover) analyses for a representative URM structure. A comparison is made to previous experimentally and analytically derived equivalents. Following this research, a recommendation is made regarding values which should be used in future design. Results of a simplified plane stress analysis for this building are also presented and compared to the results obtained from the pushover analyses.

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  • Provisional seismic assessment and improvement of Napier's Art Deco buildings

    Walsh, Kevin; Ingham, Jason (2013-04-26)

    Conference item
    The University of Auckland Library

    Following the 1931 Hawke???s Bay earthquake, buildings in Napier and surrounding areas were rebuilt in a comparatively homogenous structural and architectural style comprising the region???s famous Art Deco stock. These ???interwar buildings??? are most often composed of reinforced concrete frames and, while detailed in a fairly ductile fashion for the time, often register as earthquake-prone in preliminary seismic assessments, causing concern to owners, tenants, city officials, and all of those who value the heritage and future use of these iconic structures. The study reported here will address aspects of the seismic hazard, assessment, and potential retrofit solutions for Napier???s Art Deco buildings. The study concluded with provisional recommendations developed in collaboration with the Napier Art Deco Trust and other interested parties regarding a pathway to alleviate the hazard posed by Napier???s Art Deco buildings.

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  • Experimental pull-out test program of wall-to-diaphragm adhesive connections and observations from 2010/2011 Canterbury earthquakes

    Dizhur, Dmytro; Ingham, Jason; Campbell, J; Schultz, A (2013-04-26)

    Conference item
    The University of Auckland Library

    The connections between walls of unreinforced masonry (URM) buildings and flexible timber diaphragms are critical building components that must perform adequately before desirable earthquake response of URM buildings may be achieved. Field observations made during the initial reconnaissance and the subsequent damage surveys of clay brick URM buildings following the 2010/2011 Canterbury, New Zealand earthquakes revealed numerous cases where anchor connections joining masonry walls or parapets with roof or floor diaphragms appeared to have failed prematurely. These observations were more frequent for adhesive anchor connections than for through-bolt connections (i.e. anchorages having plates on the exterior fa??ade of the masonry walls). Subsequently, an in-field test program was undertaken in an attempt to evaluate the performance of adhesive anchor connections between unreinforced clay brick URM walls and roof or floor diaphragm. The study consisted of a total of almost 400 anchor tests conducted in eleven existing URM buildings located in Christchurch, Whanganui and Auckland. Specific objectives of the study included the identification of failure modes of adhesive anchors in existing URM walls and the influence of the following variables on anchor load-displacement response: adhesive type, strength of the masonry materials (brick and mortar), anchor embedment depth, anchor rod diameter, overburden level, anchor rod type, quality of installation and the use of metal mesh sleeve. In addition, the comparative performance of bent anchors (installed at an angle of minimum 22.5o to the perpendicular projection from the wall surface) and anchors positioned horizontally was investigated. Observations on the performance of wall-to-diaphragm connections in the 2010/2011 Canterbury earthquakes, a snapshot of the performed experimental program and the test results and a preliminary proposed pull-out capacity of adhesive anchors are presented herein.

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  • Assessment of shear stress limits on high-strength, prestressed concrete bridge beams

    Al-Ani, M; Ingham, Jason; Wiles, P (2013-10-03)

    Conference item
    The University of Auckland Library

    The aim of the research is to determine whether current limits on allowable shear stresses, as specified in NZS 3101, are appropriate when high strength concrete is used. A study of current international design standards is presented, comparing the shear stress limit provisions set out in each standard and their relative effect on the design of typical bridge beam sections. The details of a series of large scale laboratory tests, planned as the next stage of this research, are also presented. The results obtained from the experimental investigation will be presented at the conference, and will be used to assess the validity of the 8 MPa shear stress limit, with findings to be presented to the standards committee for recommendations of future amendments of the design standards.

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  • Implications of the Canterbury earthquake sequence for Adelaide, South Australia

    Griffith, MC; Moon, L; Ingham, Jason; Derakhshan, H (2013-06-02)

    Conference item
    The University of Auckland Library

    The city of Christchurch has experienced over 10,000 aftershocks since the 4th of September 2010 earthquake of which approximately 50 have been greater than magnitude 5. The damage caused to URM buildings in Christchurch over this sequence of earthquakes has been well documented. Due to the similarity in age and construction of URM buildings in Adelaide, South Australia and Christchurch (they are sister cities, of similar age and heritage), an investigation was conducted to learn lessons for Adelaide based on the Christchurch experience. To this end, the number of URM buildings in the central business districts of both cities, the extent of seismic strengthening that exists in both cities, and the relative earthquake hazards for both cities were considered. This paper will report on these findings and recommend strategies that the city of Adelaide could consider to significantly reduce the seismic risk posed by URM buildings in future earthquake.

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  • Seismic Assessment and Retrofit Prioritisation of Auckland Council???s Property Portfolio

    Walsh, Kevin; Short, N; Cummuskey, P; Ingham, Jason (2013-11-15)

    Conference item
    The University of Auckland Library

    Territorial authorities in New Zealand are responding to regulatory and market forces in the wake of the 2011 Christchurch earthquake to assess and retrofit buildings determined to be particularly vulnerable to earthquakes. Pending legislation may shorten the permissible timeframes on such seismic improvement programmes, but Auckland Council???s Property Department is already engaging in a proactive effort to assess its portfolio of approximately 3500 buildings, prioritise these assets for retrofit, and forecast construction costs for improvements. Within the programme structure, the following varied and often competing factors must be accommodated: * The council???s legal, fiscal, and ethical obligations to the people of Auckland per building regulations, health and safety protocols, and economic growth and urban development planning strategies; * The council???s functional priorities for service delivery; * Varied and numerous stakeholders across the largest territorial region in New Zealand in both population and landmass; * Heritage preservation and community and cultural values; and * Auckland???s prominent economic role in New Zealand???s economy which requires Auckland???s continued economic production post-disaster. Identifying those buildings most at risk to an earthquake in such a large and varied portfolio has warranted a rapid field assessment programme supplemented by strategically chosen detailed assessments. Furthermore, Auckland Council will benefit greatly in time and resources by choosing retrofit solutions, techniques, and technologies applicable to a large number of buildings with similar configurations and materials. From a research perspective, the number and variety of buildings within the council???s property portfolio will provide valuable data for risk modellers on building typologies in Auckland, which are expected to be fairly representative of the New Zealand building stock as a whole.

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  • Experimental testing and modelling to improve the resilience of buildings with concrete walls during earthquakes

    Henry, Richard; Ingham, Jason (2013)

    Conference item
    The University of Auckland Library

    A large number of reinforced concrete (RC) buildings were damaged during the 2010/2011 Canterbury earthquakes in New Zealand. In particular, severe and irreparable damage occurred to several RC walls. The performance of RC walls during the earthquakes has been examined and the observed damage was correlated against the expected performance levels. Both experimental testing and numerical modeling is underway to understand the observed performance of RC walls and to developed methods to improve their resilience during future earthquakes. Additionally, low-damage wall systems have been investigated that offer shift in design philosophy to meet the public expectation of building performance to earthquake and other hazards.

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  • Overview on the strengthening of New Zealand???s Unreinforced Masonry Buildings Using Engineered Cementitious Composite (ECC) Shotcrete

    Lumantarna, R; Lin, Y; Ingham, Jason; Wotherspoon, Liam; Lawley, D (2013)

    Conference item
    The University of Auckland Library

    Unreinforced masonry (URM) is a construction type that was commonly adopted in New Zealand between the 1880s and 1930s. URM construction is evidently vulnerable to high magnitude earthquakes, with the most recent New Zealand example being the 22 February 2011 Mw6.3 Christchurch earthquake. This earthquake caused significant damage to a majority of URM buildings in the Canterbury area and resulted in 185 fatalities. Many URM buildings still exist in various parts of New Zealand today, and due to their likely poor seismic performance, earthquake assessment and retrofit of the remaining URM building stock is necessary as these buildings have significant architectural heritage and occupy a significant proportion of the nation???s building stock. A collaborative research programme between the University of Auckland and Reid Construction Systems was conducted to investigate an economical yet effective solution for retrofitting New Zealand???s existing URM building stock. This solution adopts the shotcrete technique using an Engineered Cementitious Composite (ECC), which is a polyvinyl alcohol fibre reinforced mortar that exhibits strain hardening characteristics. Collaborations have been formed with a number of consulting structural engineers throughout New Zealand to develop innovative and cost effective retrofit solutions for a number of buildings. Two such case studies are presented in this paper.

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