307 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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  • Structural testing of enhanced post-tensioned concrete masonry walls

    Laursen, Peter; Ingham, Jason (2004)

    Journal article
    The University of Auckland Library

    The in-plane response of post-tensioned concrete masonry walls with unbonded tendons, incorporating strengthened masonry and enhanced energy dissipation, is examined by means of structural testing. An introduction to the testing program is followed b

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  • Detecting Flushing of Thin-Sprayed Seal Pavements Using Pavement Management Data

    Kodippily, Sachi; Henning, Theunis; Ingham, Jason (2012-05)

    Journal article
    The University of Auckland Library

    Flushing is a pavement surface defect which affects the structural integrity of thin sprayed seal (chip seal) surfacings. Analysis was carried out on pavement performance data to determine the combination of factors that provide the best indication of flushing occurrence on in‐service pavements. Data were sourced from the Long‐Term Pavement Performance programme in New Zealand (NZ‐LTPP) as well as from field testing. The LTPP data were analysed in four categories; pavement composition characteristics, traffic‐related factors, climatic factors and effects of other pavement defects. Factor and correlation analyses were used to determine and investigate the factors that showed significant relationships to flushing. Surface thickness, surface age, surfacing type and rutting were found to have statistically significant correlations to flushing. Field testing provided data relating to the soil moisture environment under the pavement. The dry density and water content of soil were identified as having significant correlations to flushing. Regression analysis of the combination of these factors yielded a robust model to identify flushing.

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  • Innovative seismic design of a post-tensioned concrete masonry house

    Wight, Gavin; Ingham, Jason; Wilton, AR (2007)

    Journal article
    The University of Auckland Library

    Post-tensioned concrete masonry walls provide improved seismic performance, but have had limited application in seismic regions because of a lack of research pertaining to their in-plane response. Following focused research over recent years, a consortium of product suppliers has collaborated with the University of Auckland to construct New Zealand’s first post-tensioned concrete masonry house. A feature of this innovative design was that all incorporated products were commercially available, with no proprietary products being specifically developed for the prestressed masonry system used. Consequently, it is hoped that this house will be a showcase, and provide exposure for the technology in New Zealand and elsewhere. This paper provides a brief review of previous post-tensioned concrete masonry research applications, then discusses post-tensioning details and their application to house design and construction.

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  • Direct Displacement-Based Seismic Design of unbonded Post-Tensioned Masonry Walls

    Wight, Gavin; Kowalsky, Mervyn; Ingham, Jason (2007)

    Journal article
    The University of Auckland Library

    Post-tensioned masonry walls exhibit desirable seismic performance characteristics due to increased in-plane strength and the absence of residual lateral displacement at the conclusion of seismic loading. The direct displacement-based design (DDBD) approach aims to provide a method whereby a structure may be designed to achieve a predefined level of lateral deformation under a predefined level of earthquake intensity. This paper details the development of a DDBD procedure to assist in the design of unbonded post-tensioned masonry structural walls. The level of initial tendon prestress is shown to have a significant effect on wall response and guidance is provided for making this design choice. An acceptable correlation is demonstrated when the results from the method are compared with actual data obtained from previous shake table testing of three full-scale concrete masonry walls. The paper concludes by presenting a design example that highlights the steps involved in applying this approach to an actual wall structure and demonstrates the simplicity of the method.

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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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  • 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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  • 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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  • The effects of axial restraint in reinforced concrete coupling beams

    Malcolm, Richard; Bull, DK; Henry, Richard; Ingham, Jason (2014-10-09)

    Conference item
    The University of Auckland Library

    Axial elongation of reinforced concrete (RC) plastic hinges has previously been observed in a range of laboratory experiments, and more recently was observed in several Christchurch buildings following the 2010/2011 Canterbury earthquakes. Axial restraint to plastic hinges is provided by adjacent structural components such as floors as the plastic hinges elongate, which can significantly alter the performance of the plastic hinge and potentially invalidate the capacity design strength hierarchy of the building. Coupling beams in coupled wall systems are particularly susceptible to axial restraint effects due to their importance in the strength hierarchy, the high ductility demands that they experience, and the large stiffness of bounding walls. From computational modelling it has been found that ignoring axial restraint effects when designing coupled walls can result in significantly increased strength, reduced ductility and reduced energy dissipation capacity. The complexity of the topic merits further research to better account for realistic restraint effects when designing coupled walls.

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  • In-situ out-of-plane testing of unreinforced masonry partition walls

    Dizhur, Dmytro; Derakhshan, Hossein; Ingham, Jason; Griffith, MC (2009)

    Conference item
    The University of Auckland Library

    Most of the research considering out-of-plane seismic assessment of URM walls has been conducted using laboratory-based studies with artificial boundary conditions. Thus, in-situ testing is required to provide data with which to validate the accuracy of laboratory-based studies of out-of-plane walls. An in-situ testing program was developed by performing airbag tests on 2 non-load bearing partition walls of the William Weir Wing of Weir House in the city of Wellington, New Zealand. The 3 storey building was constructed in 1932 and is comprised of reinforced concrete perimeter walls with cement plaster and terracotta masonry interior facing with unreinforced terracotta masonry partition walls. One wall was tested in the as-built condition and the second wall was retrofitted with Carbon Fibre Reinforced Polymers (CFRP) using the Near Surface Mounting (NSM) technique. The pseudo-static tests were performed on the surface of the 1-leaf clay brick terracotta masonry walls by applying uniform pressure. The test walls, having dimensions of 3600 mm by 4100 mm, were supported at four sides and acted in a two-way bending mode. The test procedure and measured strength and stiffness properties of the two walls are presented.

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  • Experimental testing and modelling to address the performance of RC walls during the 2010/2011 Canterbury earthquakes

    Henry, Richard; Lu, Yiqiu; Ingham, Jason (2014-07-21)

    Conference item
    The University of Auckland Library

    The current seismic design practice for reinforced concrete (RC) walls has been drawn into question following the unsatisfactory performance of several RC wall buildings during the Canterbury earthquakes. An overview of current research being undertaken at the University of Auckland into the seismic behaviour of RC walls is presented. The main objectives of this research project are to understand the observed performance of RC walls in Christchurch, quantify the seismic loads on RC walls, and developed improved design procedures for RC walls that will assist in revisions to the New Zealand Concrete Structures Standard. A database summarising the performance of RC wall buildings in the Christchurch CBD was collated to identify damage modes and case-study buildings. A detailed investigation is underway to verify the seismic performance of lightly reinforced concrete walls and initial numerical modeling and small-scale tests are presented in addition to details of planned experimental tests of RC walls. Numerical modelling is being used to understand the potential influence that interactions between walls and other structural elements have on the seismic response of buildings and the loads generated on RC walls. The results from finite element analysis of a severely damaged RC wall in Christchurch highlighted the effect that the floor diaphragms have on the distribution of shear stains in the wall.

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  • Out-of-plane behaviour of connections between precast concrete panels and their foundations

    Burley, J; Faitotoa, T; Seifi, Pouya; Henry, Richard; Ingham, Jason (2014-10-09)

    Conference item
    The University of Auckland Library

    Precast concrete panels are commonly used throughout New Zealand in both low-rise industrial buildings and multi-storey buildings. The panel connection details vary depending on the building and connection type. Following the Canterbury earthquakes, concerns have been raised regarding the seismic behaviour of several different types of precast panel connections. One particular concern is the out-of-plane behaviour of shallow embedded anchors used in wall-to-foundation connections in low-rise industrial buildings. This type of connection is commonly used within the precast industry, and therefore it is essential to understand the expected seismic performance. A comprehensive experimental investigation is underway to assess the out-of-plane behaviour of different panel-to-foundation connection details using threaded inserts. A test setup was developed to simulate the expected shear and bending actions on the panel during an earthquake using a horizontal jack positioned at a certain height up the panel. A total of 12 panels were designed to represent commonly constructed connection details.

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  • Force-based elastic seismic assessment of New Zealand unreinforced masonry buildings

    Russell, Alistair; Laursen, Peter; Ingham, Jason (2009)

    Conference item
    The University of Auckland Library

    Because of the need for a straightforward procedure for assessing the performance of low rise unreinforced masonry structures in New Zealand a force-based, elastic method of analysis for a critical design earthquake is proposed. The comparatively low value of many URM structures in New Zealand justifies a simplified approach and a force-based method has the advantage of familiarity and simplicity. The criteria which the performance of existing buildings must be measured against in New Zealand is defined as one-third the strength of a design earthquake. The procedure for determining the seismic demand to which an existing structure is subjected, as well as how the structure can be analysed to determine the capacity of masonry walls responding in-plane to withstand that demand, are described. It is determined that an equivalent static analysis (ESA) procedure is appropriate for the seismic assessment of low-rise URM structures in New Zealand.

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  • Strength assessment of typical wall-diaphragm connections in New Zealand URM buildings

    Abdul Karim, Abdul Razak; Quenneville, Pierre; M Sa'Don, N; Ingham, Jason (2009)

    Conference item
    The University of Auckland Library

    Most unreinforced masonry (URM) buildings in New Zealand consist of solid URM bearing walls and flexible timber diaphragms (floor and roof), and insufficient or absent positive anchorage between URM walls and diaphragms has previously been identified to be the most common reason for out-of-plane wall and gable failures in URM buildings during earthquakes. A series of case studies was performed to determine typical details for wall-diaphragm connections, to ensure that realistic specimens were reproduced in laboratory testing to accurately assess their strength. It was found that typical wall-diaphragm connections in New Zealand were throughbolt anchors, where one end of a threaded steel rod was bolted with a steel bearing plate at the exterior face of the URM wall and the other end was welded to a rectangular steel plate that bolted to the timber joist. This type of anchor was believed to be applied as a retrofit technique to most New Zealand URM buildings following the 1931 Hawke’s Bay earthquake. In order to assess the strength and possible modes of failure of the wall-diaphragm connections, two types of testing were conducted as follows: (1) pull-out tests on URM wall with typical through-bolt anchor type; and (2) bolted timber connection tests loaded parallel to the timber grain.

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  • The effect of reinforcement strength on the overstrength factor for reinforced concrete beams

    Brooke, NJ; Ingham, Jason (2011-04-14)

    Conference item
    The University of Auckland Library

    The design of earthquake resistant structures in New Zealand is based around the philosophy known as capacity design. In order for this philosophy to be successfully applied, it is essential that the flexural overstrength factor is appropriately defined. Overstrength factors for reinforced concrete structures are defined in the New Zealand Concrete Structures Standard, NZS 3101:2006, which currently prescribes the flexural overstrength factor for beams as 1.25 if the beam contains Grade 300E longitudinal reinforcement and as 1.35 if the beam contains Grade 500E longitudinal reinforcement. However, review of existing literature and consideration of structural behaviour does not support the use of different overstrength factors for different types of reinforcement. Analysis of a database of approximately one hundred beam-column joint tests indicates that the same overstrength factor should be used for reinforced concrete beams irrespective of whether they contain Grade 300E or Grade 500E longitudinal reinforcement.

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  • Wall-diaphragm connection assessment guideline for URM buildings

    Abdul Karim, AR; Quenneville, Pierre; Sa'don, NM; Ingham, Jason (2011-04-14)

    Conference item
    The University of Auckland Library

    The connections between walls and diaphragm in unreinforced masonry (URM) buildings typically consist of two major parts. The first part is the wall anchorages and the second part is the diaphragm connections. From the NZNSEE (1995) and FEMA (2006) guidelines, the connection strength values given by both guidelines are apparently related only with the possible failures of the masonry wall anchorages, and no procedures are currently available to identify the strength values related to failure of the timber bolted connections. This latter failure mode is important to consider as the minimum strength value that will govern the wall-diaphragm connection capacity can be acquired from the diaphragm connections. To counter this limitation, this study recommends a set of design equations to assess the strength of the timber bolted connections. By using these equations, in addition to the default connection strength values provided by the guidelines, the expected strength level of wall-diaphragm connections can be accurately assessed.

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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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  • Assessment of the material properties of New Zealand's unreinforced masonry building stock

    Russell, Alistair; Mahmood, Hamid; Ingham, Jason (2007)

    Conference item
    The University of Auckland Library

    Unreinforced masonry (URM) buildings in New Zealand were constructed mainly between about 1880 and 1950. These buildings are regarded as seismically at-risk, and because they represent a significant part of New Zealand’s architectural heritage structures, they are prime candidates for seismic retrofit. Currently a large-scale research project focused on developing retrofit solutions for New Zealand’s earthquake risk URM buildings is being undertaken, and within this programme it was determined that the first task to be completed was the development or adoption of accurate seismic assessment techniques, and that within this task the primary issue was accurate determination of material properties. Material properties of URM in New Zealand are unique, and currently there is a significant lack of adequate and accurate material data. Without accurate material data, overly conservative assessments and correspondingly expensive retrofit interventions are required. The use of accurate material data is essential in ensuring that heritage architecture is maintained, and not demolished. This paper discusses the difficulties in procuring material samples and the findings on both lab and field studies investigating the compression, shear and flexural tension strength of unreinforced masonry. Significant variation in the properties between and within buildings has been encountered. It is determined that due to the highly variable nature of URM, testing must be conducted not only on individual materials, but their interactions with each other, particularly the interaction between mortar and bricks.

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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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