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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  • Assessing the validity of rocking in URM perforated shear walls

    Knox, Charlotte; Ma, QT; Ingham, Jason (2010)

    Conference item
    The University of Auckland Library

    The validity of implementing a ‘rocking wall retrofit’ for New Zealand’s earthquake prone unreinforced masonry buildings was assessed. The parameters governing rocking response are detailed, and the identification of rocking-sympathetic characteristics in representative New Zealand unreinforced masonry building typologies are highlighted. A series of experimental tests were conducted in order to identify variables that had potential to alter the rocking response of piers subjected to seismic loading. The influence of boundary conditions on the failure mechanism of unreinforced masonry piers is discussed in relation to the design of the full scale testing rig. Results from testing of two full scale unreinforced masonry sub-structures consisting of two piers coupled by a deep spandrel are reported. The tests access the influence of aspect ratio and vertical precompression levels on the forcedisplacement and pier-spandrel rotational behaviour. Crack patterns evidenced in a series of plaster formed scale models is compared to those developed during full scale pseudo-static cyclic tests on unreinforced masonry shear walls of the same geometry.

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  • Experimental Investigation of Rigid Body Rocking

    ElGawady, Mohamed; Ma, QT; Ingham, Jason; Butterworth, John (2005)

    Conference item
    The University of Auckland Library

    This paper presents the preliminary results of an experimental investigation on the behaviour of blocks under rigid body rocking. Nine blocks with different aspect ratios were tested with varying initial amplitudes and different materials at the contact interface. Three different materials, namely concrete, timber, and steel were used to construct the base on which the blocks could rock. The rocking characteristics of the blocks were compared to the predictions by Housner’s simple rocking model (SRM). Preliminary results show that the rocking response is strongly dependent upon the aspect ratio of the block, in general accordance to SRM. In addition, different materials at the contact interface play an essential role on the block’s rocking responses.

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  • Predicting the In-Plane Rocking Behaviour of Post-Tensioned Concrete Walls Subjected to Earthquake Excitations

    Ma, QT; Wight, Gavin; Butterworth, John; Ingham, Jason (2005)

    Conference item
    The University of Auckland Library

    The current capability of predicting the dynamic rocking response of post-tensioned concrete systems when subjected to earthquake excitations is examined herein. Shake table test results of a post-tensioned concrete masonry wall were compared to the simulation results from three frequently used numerical simulation procedures. This exercise highlighted significant deficiencies with the current methods and identified energy dissipating mechanisms as the primary modelling challenge for a successful simulation. The findings of this paper cast doubts on the anecdotal claims that the dynamic behaviour of controlled rocking systems can be accurately modelled.

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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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  • Residual strength assessment and destructive testing of decommissioned concrete bridge beams with corroded pre-tensioned reinforcement

    Rogers, RA; Wotherspoon, Liam; Scott, A; Ingham, Jason (2011)

    Conference item
    The University of Auckland Library

    Recent deterioration of pretensioned concrete bridge beams in New Zealand and Australia highlights an escalating problem. Pretensioned reinforcement corrosion is especially critical because of the highly stressed nature of the structures. Only a small amount of corrosion is required to a pretensioned strand before a considerable reduction of the structural capacity of the member occurs. The Tiwai Point Bridge is located in a highly aggressive environment near Invercargill in the South Island of New Zealand. It consists of twenty seven 60 ft (18 m) spans; each span consists of nine 2‘3“ (686 mm) deep tee beams which contain both pretensioned and posttensioned reinforcement. The bridge was opened in 1969 and since that time chloride ingress has resulted in severe corrosion of the pretensioned reinforcement. Each beam was subjected to a number of non-destructive corrosion assessment procedures. These results were used to estimate the ultimate strength of each beam. Each beam was then loaded to failure on a custom built four point flexural testing rig. The worst condition beams had damage to all four strands in the bottom layer and achieved strengths of 68% and 69% of their good condition counterparts. The aim of this research was to assess the residual strength of beams which had experienced pretensioned reinforcement corrosion. The progression of corrosion damage observed in the beams was described and a model was presented for assessment of the beams using nondestructive means. The measured strength of the corroded beams was compared to nominally identical beams which had not experienced corrosion.

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  • Development of New Zealand's first post-tensioned concrete masonry home

    Wight, Gavin; Ingham, Jason; Kowalsky, MJ; Wilton, AN (2004)

    Conference item
    The University of Auckland Library

    Researchers from The University of Auckland are involved in the development, design and construction of the first post-tensioned concrete masonry (PCM) home in New Zealand. This paper provides details of the post-tensioned wall system that has been developed, a summary of the cyclic and dynamic tests conducted on these wall types thus far and an outline of how the walls will be designed and constructed for a residential structure.

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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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  • Diagonal shear testing of unreinforced brick-masonry wallettes retrofitted with CFRP plates

    Mahmood, Hamid; Ingham, Jason (2009)

    Conference item
    The University of Auckland Library

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  • Strut-and-Tie Modelling of Fibre Reinforced Precast Concrete Beam-Column Joints

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

    Conference item
    The University of Auckland Library

    In this paper, topics related to the use of fibre reinforced cementitious composites (FRCCs) in beam-column joint cores are discussed. A review is presented of the ways in which FRCCs are classified, from which it is concluded that development of reliable methods for assessing the tensile properties of FRCCs is essential. Key results are presented from the testing of two beam-column joint sub-assemblies with FRCC joint cores, and a qualitative assessment is made of the mechanisms by which forces were transferred through the joint core. The paper is concluded with a discussion of the expected performance of further beam-column joints currently being tested.

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  • The Influence of Axial Compression on the Elongation of Plastic Hinges in Reinforced Concrete Beams

    Cooper, Martin; Davidson, Barry; Ingham, Jason (2005)

    Conference item
    The University of Auckland Library

    Four reinforced concrete beams were tested to investigate the effect of axial force on the elongation that occurs in plastic hinge zones. The beams, designed to replicate the corresponding detail from a multi-storey moment resisting frame, were cyclically tested whilst being subjected to different constant axial forces. The axial forces, up to 0.0833 Agfc‘, were applied to replicate the beam-slab interaction that acts to restrict elongation. The influence of moment and shear on elongation was tested respectively by using different reinforcement and length details for different tests. All the beams tested were 450 mm deep and 200 mm wide. A detailed account of beam construction, test setup, testing procedure and test results are provided in this paper.

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  • Vibration testing of an in situ bridge pier to determine soil-structure interaction effects

    Hogan, Lucas; Wotherspoon, Liam; Beskhyroun, Sherif; Ingham, Jason (2012-09-24)

    Conference item
    The University of Auckland Library

    The lateral dynamic response characteristics of a single span from the decommissioned Puhinui Stream Bridge in Manukau, New Zealand were determined through a series of forced vibration tests performed along the longitudinal axis of the bridge using an eccentric mass shaker. Following forced vibration testing, the dynamic characteristics of a three column pier group from the span were determined using snapback testing. Responses of the bridge span and pier group measured during the vibration testing were used to construct finite element models accounting for soil-structure interaction using a Winkler spring idealisation of the soil. Because of the simplified nature of the pier group, it was modelled first, and used to perform sensitivity analyses to obtain realistic bounds for soil and material properties based upon CPT data and concrete specifications. The pier group model will be extended to capture the response measured by the forced vibration testing of the bridge span but is not discussed here.

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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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  • 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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  • 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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  • Bridge Knee Joint with Headed Reinforcement

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

    Conference item
    The University of Auckland Library

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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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