198 results for Ingham, Jason, Conference item

  • 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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  • 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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  • Shake Table Testing of Post-Tensioned Concrete Masonry Walls

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

    Conference item
    The University of Auckland Library

    Six single-storey unbonded post-tensioned concrete masonry (PCM) walls were tested on a single dimension shake table at North Carolina State University. The principal intent of this study was to validate the use of PCM for residential construction, before the first PCM house is built in New Zealand. Three rectangular walls were tested to demonstrate the seismic performance of post-tensioned rocking walls, followed by walls containing a door and window opening and a shrinkage control joint. A detailed account of wall construction, test setup, testing procedure and test results are provided in this paper.

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  • Unreinforced stone masonry buildings in New Zealand: Inventory and material characterisation

    Giaretton, M; Dizhur, Dmytro; da Porto, F; Ingham, Jason (2014-07-07)

    Conference item
    The University of Auckland Library

    The high seismic vulnerability of unreinforced stone masonry (URM) buildings was once again demonstrated in the recent Canterbury earthquakes (2010-2011). The shortage of knowledge about New Zealand historic URM buildings, and about techniques for their conservation, led to numerous losses, both in terms of lives and architectural heritage. Almost all URM buildings in New Zealand were constructed between 1860 and 1910, typically in regions where natural stone (in particular basalt, schist and limestone) was sourced from local quarries, fields and rivers. There are estimated to be approximately 688 URM buildings in New Zealand, with most being a potential earthquake risk. As a first step, an inventory of the URM buildings of New Zealand was compiled, listing location, construction details and architectural configuration. A further development was the inspection of representative case study buildings, where architectural characteristics and extracted material samples were obtained. Compressive tests and petrographical analyses were undertaken on natural stone specimens, while compressive strength and mineralogical composition were determined for mortar samples. The aim of the study reported herein was to acquire a thorough understanding of the mechanical and physical properties of these URM buildings in order to assess seismic vulnerability factors and potential seismic improvement solutions.

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  • Advanced Fibre Reinforced Precast Concrete Beam-Column Joints

    Brooke, Nicholas; Ingham, Jason (2006)

    Conference item
    The University of Auckland Library

    This paper provides an overview of an ongoing research project at The University of Auckland that is investigating the potential of ductile fibre reinforced cementitious composites (DFRCC) as a structural material in New Zealand. A brief overview of international research on DFRCC is given, including an explanation of how DFRCC differs from conventional fibre reinforced concrete. Researchers at The University of Auckland have begun mixing trial batches of DFRCC, and this paper gives some results from this investigation, along with comments about experience obtained from mixing these trial batches. To date DFRCC has not been successfully produced, although tensile properties of the concrete are significantly better than plain concrete. Finally, details are presented of an innovative method of constructing equivalent monolithic moment resisting frames using DFRCC connections to join precast concrete beam and column elements.

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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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  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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  • 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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  • Cyclic out-of-plane behaviour of post-tensioned clay brick masonry

    Ismail, N; Laursen, PT; Schultz, AE; Ingham, Jason (2011-06-05)

    Conference item
    The University of Auckland Library

    Out-of-plane flexural testing of three (03) full scale unreinforced masonry (URM) walls seismically retrofitted using post-tensioning is reported. The selected wall configurations were representative of common URM walls that were vulnerable to out-of-plane failure, and imitated heritage URM construction by using salvaged clay brick masonry and ASTM type O mortar. Varying levels of pre-compression were applied to the test walls using a single mechanically restrained tendon inserted into a cavity at the centre of each test wall. Behaviour of the post-tensioned URM walls was compared to the response of a non-retrofitted URM wall, with the out-of-plane flexural strength of the post-tensioned masonry walls observed to range from 2.9 to 10.3 times the strength of the non-retrofitted URM wall. Several aspects pertaining to the seismic behaviour of post-tensioned masonry walls were investigated, including tendon stress variation, damage patterns, force-displacement behaviour, initial stiffness, and displacement capacity. Test results were compared with equations developed in previous studies, and it was established that the walls that were post-tensioned using seven-wire strands had measured strengths that compared favourably with predicted values, whereas the wall that was post-tensioned using mild steel bar had failed at a lower measured strength than the predicted value.

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