196 results for Ingham, Jason, Conference item

  • 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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  • Bridge Knee Joint with Headed Reinforcement

    Ingham, Jason; Priestley, Nigel; Seible, F (1995)

    Conference item
    The University of Auckland Library

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  • Strut-and-Tie Model Concepts for Seismic Design and Assessment of Concrete Bridge Joints

    Sritharan, S; Ingham, Jason; Priestley, MJN (2000)

    Conference item
    The University of Auckland Library

    A comprehensive experimental and analytical study on bridge cap beam-to-column concrete joints has been conducted at the University of California at San Diego (UCSD) over the past decade. In this study, the improvement of both detailing and the in-plane seismic performance of bridge joints has been examined by representing the force transfer across the joint using simple strut-and-tie models, which evolved into a rational force transfer method for designing and assessing bridge joints subjected to seismic actions. Starting with joint force conditions and failure modes, this methodology is described in this paper. Some specific strut-and-tie details relevant to seismic behaviour of bridge joints are then discussed, followed by several key joint mechanisms and examples of design models to facilitate application of the proposed method.

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  • The Seismic Behaviour of Reinforced Concrete Beam-Column Knee Joints for Buildings

    Megget, Leslie; Ingham, Jason (1996)

    Conference item
    The University of Auckland Library

    This paper describes the cyclic testing of two half-scale reinforced concrete beam-column building knee joints designed to the 1995 New Zealand Concrete Standard, NZS 3101 (1995). The two knee joints were identical, except that one had a standard hook detail for the beam bottom bars and column internal bars while the other unit had beam and column U-bars in the joint region. Both units approached their nominal strengths under both opening and closing bending moments. The hooked unit developed a joint shear failure at displacement ductilities greater than 4, while the U-bar unit was able to form a reversing beam plastic hinge with little joint deterioration, although some joint cover concrete was lost. The maximum levels of joint shear sustained in these two units approached 0.1 f MPa, this being only half of the limiting joint shear stress specified in the NZ Concrete Standard.

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  • Digital buildings: Using sensors to monitor the performance of concrete buildings during the Christchurch earthquake rebuild

    Simkin, Gye; Ingham, Jason (2014-06-11)

    Conference item
    The University of Auckland Library

    Following the devastation of the Canterbury earthquake sequence a unique opportunity exists to rebuild and restructure the city of Christchurch, ensuring that its infrastructure is constructed better than before and is innovative. By installing an integrated grid of modern sensor technologies into concrete structures during the rebuild of the Christchurch CBD, the aim is to develop a network of self-monitored ???digital buildings???. A diverse range of data will be recorded, potentially including parameters such as concrete stresses, strains, thermal deformations, acoustics and the monitoring of corrosion of reinforcement bars. This procedure will allow an on-going complete assessment of the structure???s performance and service life, both before and after seismic activity. The data generated from the embedded and surface mounted sensors will be analysed to allow an innovative and real-time health monitoring solution where structural integrity is continuously known. This indication of building performance will allow the structure to alert owners, engineers and asset managers of developing problems prior to failure thresholds being reached. A range of potential sensor technologies for monitoring the performance of existing and newly constructed concrete buildings is discussed. A description of monitoring work conducted on existing buildings during the July 2013 Cook Strait earthquake sequence is included, along with details of current work that investigates the performance of sensing technologies for detecting crack formation in concrete specimens. The potential market for managing the real-time health of installed infrastructure is huge. Civil structures all over the world require regular visual inspections in order to determine their structural integrity. The information recorded during the Christchurch rebuild will generate crucial data sets that will be beneficial in understanding the behaviour of concrete over the complete life cycle of the structure, from construction through to operation and building repairs until the time of failure.

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  • Modelling the Flushing Mechanism of Thin Flexible Surfaced Pavements in New Zealand

    Kodippily, Sachi; Henning, Theunis; Ingham, Jason; CENEK, P (2010)

    Conference item
    The University of Auckland Library

    Flushing is a major cause of maintenance on chipsealed pavements in New Zealand. Accurate understanding of flushing can have a significant impact in terms of predicting future maintenance needs, expenditure, and performance of pavements. Currently available literature does not provide sufficient information to gain a mechanistic understanding of this defect. Therefore, developing a flushing forecasting model remains a priority for the road asset management sector in New Zealand. The reported research aimed to develop a mechanistic understanding of the processes involved with the flushing defect. The study primarily focused on identifying methods that can be used to investigate the particular mechanisms causing flushing on pavements based on network level data. Twenty five pavement sites on state highways of Napier/ Hawke???s Bay region of New Zealand were identified, with top surface lives ranging from three to nine years. Historical pavement data from these sites were analysed and the results combined with analysis of Long-Term Pavement Performance data to identify the main mechanisms causing flushing on chipsealed pavements. Surface depth and roughness were found to have the greatest influence on flushing, while surface texture measured by sand circles was found to be a satisfactory indicator of probable flushed chipseals. It is intended that these findings will contribute to the development of the flushing forecasting model for chipsealed pavements in New Zealand.

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  • A Masonry Design Standard for Use in Developing Countries

    Ingham, Jason (2000)

    Conference item
    The University of Auckland Library

    This paper seeks to demonstrate how a recently released design standard for concrete masonry buildings not requiring specific engineering design, NZS 4229:1999, has application not only in a New Zealand context, but that with very minor modification would readily serve as an appropriate design document in many developing countries. Research conducted in support of the document is briefly discussed, as is the composition of the standard and a supporting document containing several design examples. Key features of the design process are discussed, and changes necessary in order to use the document in other countries are detailed.

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  • Seismic Performance of Two Reinforced Concrete Knee Joints Designed to the 1995 Concrete Standard

    Megget, Leslie; Ingham, Jason (1996)

    Conference item
    The University of Auckland Library

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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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  • 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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  • 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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  • Performance of retrofitted unreinforced masonry buildings during the Christchurch earthquake sequence

    Turner, F; Elwood, Kenneth; Griffith, M; Ingham, Jason; Marshall, J (2012)

    Conference item
    The University of Auckland Library

    The performance of retrofitted unreinforced masonry (URM) bearing wall buildings in Christchurch is examined, considering ground motion recordings from multiple events. Suggestions for how the experiences in Christchurch might be relevant to retrofit practices common to New Zealand, U.S. and Canada are also provided. Whilst the poor performance of unretrofitted URM buildings in earthquakes is well known, much less is known about how retrofitted URM buildings perform when subjected to strong ground shaking.

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  • The Performance of Ductile R/C Frames under Seismic Loading

    Fenwick, Richard; Ingham, Jason; Wuu, PJ (1996)

    Conference item
    The University of Auckland Library

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  • In-Plane Sesimic Response of Joints in Multi-Column Bents of Concrete Bridges

    Ingham, Jason; Sritharan, S; Priestley, MJN; Seible, F (1996)

    Conference item
    The University of Auckland Library

    Experimental investigations were conducted on the in-plane seismic response of both exterior (knee) and interior (tee) large-scale beam-column bridge joint sub-assemblies. These investigations were supported by parallel analytical studies based on rational joint force transfer models. Utilising design strategies developed from the preliminary investigations, two further units incorporating new design techniques were tested. The application of headed reinforcement in the first unit and cap beam prestressing in the second unit greatly reduced congestion of joint reinforcement, when compared with the equivalent joints designed using conventional methods. Excellent response was obtained for both new designs, confirming the validity of the rational design procedure.

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  • Issues Associated with the use of Prestressed Masonry

    Brownlee, K; Ingham, Jason (1998)

    Conference item
    The University of Auckland Library

    Changes in construction techniques and advances in masonry design have effectively provided manufacturers and specifiers with a new structural material, prestressed concrete masonry. This material has the potential to impact on the masonry industry in a similar fashion to the influence which prestressed concrete exerted on the concrete industry. While it is beyond the scope of this paper to examine all the issues associated with prestressed concrete masonry, it is hoped that through exploring some of the major issues associated with this technology, this paper will progress the use of prestressed concrete masonry in the New Zealand construction industry.

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  • Bond Strength in Beam-Column Joints Incorporating High Strength Reinforcement

    Brooke, Nicholas; Megget, Leslie; Ingham, Jason; Fenwick, Richard (2004)

    Conference item
    The University of Auckland Library

    A database of beam-column joint test results has been assembled and analysed to determine appropriate design drift limits for the prevention of bond failure in reinforced concrete frames. In an existing data base of internal beam column joint tests there was a lack of test results of beams reinforced with high strength reinforcing bar diameters greater than 16mm. To enhance this data base and improve design criteria for bond in internal beam column joint zones a series of tests of beamcolumn sub-assemblies was planned at the University of Auckland. The results of three of these tests are described in the paper. Bond failure occurred in one of these tests with bar buckling limiting the capacity of two of the tests. There is some indication that the quantity of intermediate column bars in the joint zone influences the bond resistance. The results confirm previous observations that the flexibility of beams constructed using high-grade reinforcement, such as Grade 500E, severely reduces the structural ductility factor that should be used in seismic design.

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  • Bond strength of reinforced concrete beam column joints incorporating grade 500 MPa reinforcement

    Brooke, Nicholas; Megget, Leslie; Ingham, Jason; Fenwick, Richard (2004)

    Conference item
    The University of Auckland Library

    A database of beam-column joint test results has been assembled and analysed to determine appropriate design drift limits for the prevention of bond failure in reinforced concrete frames. In order to enhance the coverage of the database which predominantly contains units having small beam reinforcing bar sizes, further beam-column joints have been designed at the University of Auckland using 25 mm beam reinforcement. Results from the first two of these tests are reported. Despite the first unit not meeting the requirements of the recent amendment to NZS 3101:1995 with respect to column depth, the units did not exhibit a bond failure in the joint region.

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  • Overview of a Cement-stabilised Flax-fibre Reinforced Rammed Earth (Uku) Building System for New Zealand Indigenous Communities

    Cheah, Jing; Ingham, Jason; Morgan, Te Kipa (2008)

    Conference item
    The University of Auckland Library

    This paper outlines research that has been undertaken to create an accessible, low-cost, sustainable earthen building solution for Maori (the indigenous people of New Zealand) living in rural communities. Many individuals and families in rural Maori communities live in overcrowded dwellings with a low, inadequate standard of living. Reasons for the poor housing condition that exists can be attributed to legal issues regarding `Maori land` and land ownership, the urbanization of Maori, and the financial cost of constructing on isolated, undeveloped Maori land. In July 2003, a four year research grant was awarded to develop a low-cost flax-fibre reinforced rammed earth housing concept into a commercially viable building technology. An important measure of the value of the research was the ability of rural Maori communities to be able to use the outputs of the research directly. Consequently a community reference group was created comprising of representatives from potential Maori user groups/areas. During the research, an optimized Uku soil mix was determined comprising of 8% cement and 0.075% flax fibres. Material tests have also been conducted to determine the lower 5% compressive, flexural and shear design strengths of the material. The construction process was optimized throughout the research with the development of such devices as a mobile flax stripper and a custom-made formwork system. Improvements in construction methodology were also implemented. The research concluded in April 2008, with the construction of a full-size Uku house on the foreshore of Lake Rotoiti. This research has resulted in the development of a technology that rural Maori communities can immediately benefit from and has created a platform for future research and development of the Uku building system.

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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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  • A Presentation of the PRESSS Technology applied to a 39-storey building by Pankow Builders in California

    Ingham, Jason (2000)

    Conference item
    The University of Auckland Library

    This paper reviews technology transfer related to structural testing of precast post-tensioned concrete construction. The background research is briefly reviewed, with attention then given to a number of recently constructed structures utilising precast post-tensioned concrete moment-resisting frames, and built by Pankow Builders Ltd. Emphasis is given to details of a 39-storey concrete frame structure in San Francisco, California, which when completed will be the tallest concrete structure in the highest seismicity zone of California. It is concluded that there are no technical barriers to transfer of this technology to New Zealand.

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