105 results for Ingham, Jason, Journal article

  • 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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  • 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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  • 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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  • Bond Performance of Interior Beam-Column Joints with High Strength Reinforcement

    Brooke, Nicholas; Megget, Leslie; Ingham, Jason (2006)

    Journal article
    The University of Auckland Library

    Four beam-column joint tests were undertaken to assess the accuracy of New Zealand design rules relating to bond strength in beam-column joints when applied to large diameter, high-strength reinforcement. The ratio of longitudinal beam reinforcement diameter to column depth intentionally did not meet the requirements of the New Zealand design standard for any of the units. The units were subjected to cyclic displacements up to interstory drift angles of 5%. Bond failure occurred in two of the four test units, at drift levels exceeding those allowed by international codes. It is believed that the unexpectedly good bond performance of the remaining two units was due to the large excess of vertical joint shear and column moment capacity.

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  • Behaviour of tilt-up precast concrete buildings during the 2010/2011 Christchurch earthquakes

    Henry, R; Ingham, Jason (2011)

    Journal article
    The University of Auckland Library

    The Christchurch region of New Zealand experienced a series of major earthquakes and aftershocks between September 2010 and June 2011 which caused severe damage to the city’s infrastructure. The performance of tilt-up precast concrete buildings was investigated and initial observations are presented here. In general, tilt-up buildings performed well during all three major earthquakes, with mostly only minor, repairable damage occurring. For the in-plane loading direction, both loadbearing and cladding panels behaved exceptionally well, with no significant damage or failure observed in panels and their connections. A limited number of connection failures occurred due to large out-of-plane panel inertia forces. In several buildings, the connections between the panel and the internal structural frame appeared to be the weakest link, lacking in both strength and ductility. This weakness in the out-of-plane load path should be prevented in future designs.

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  • Compressive, Flexural Bond, and Shear Bond Strengths of In Situ New Zealand Unreinforced Clay Brick Masonry Constructed Using Lime Mortar between the 1880s and 1940s

    Lumantarna, R; Biggs, D; Ingham, Jason (2014-04)

    Journal article
    The University of Auckland Library

    The importance of sufficient masonry mortar joint-bond strength when a structure is subjected to in-plane and out-of-plane loads has been emphasized by several researchers. However, masonry unit/mortar bond strength is difficult to predict, and performing mechanical tests on existing masonry buildings to determine masonry flexural bond and shear bond strengths is generally not practical, such that predictive expressions relating the masonry flexural bond and shear bond strengths to other masonry properties are desirable. Although relationships between brick/mortar bond and compressive strength have been investigated previously by researchers located in many different parts of the world, most of these studies were laboratory-based and did not include testing of existing masonry buildings within their scope. The writers aimed to characterize the material properties of New Zealand unreinforced clay brick masonry (URM) buildings that were generally built between 1880 and 1930, with in situ testing and sample extraction performed on six heritage buildings. Masonry compression, bond wrench, and shear bond tests were undertaken. The experimental results indicate that the masonry flexural bond strength and bed-joint cohesion can be satisfactorily related to the mortar compressive strength.

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  • Lateral Force-Displacement Response of Unreinforced Masonry Walls with Flanges

    Russell, AP; Elwood, Kenneth; Ingham, Jason (2014-04)

    Journal article
    The University of Auckland Library

    The experimental in-plane force-displacement response of unreinforced masonry (URM) walls with flanges (return walls) subjected to pseudo-static cyclic lateral loading is presented. Each wall failed in a diagonal tension mode followed by bed-joint sliding. The effect of wall flanges was an increase in the displacement capacity of the in-plane loaded wall, in comparison with an in-plane loaded wall without flanges. The measured shear strengths of the walls were compared with an analytical model for determining the limiting diagonal tension strength of the walls, with a high level of correlation. The initial stiffness of the shear walls before the effective yield was compared with the initial stiffness as determined using conventional principles of mechanics for homogeneous materials, and it was found that with some approximations the initial stiffness could be satisfactorily determined. Because the bed-joint sliding failure mechanism exhibited by the walls is a deformation-controlled action, there is further displacement capacity beyond the effective yield displacement, and it was found that the walls could sustain in-plane lateral forces to a drift of at least 0.7%. Recommendations are provided for a general force-displacement relationship, which is consistent with the experimental data and can be used for modeling URM walls and improving acceptance criteria, such as those specified in ASCE/SEI 41-06.

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  • Quantifying the Effects of Chip Seal Volumetrics on the Occurrence of Pavement Flushing

    Kodippily, Sachi; Henning, Theunis; Ingham, Jason; Holleran, G (2014)

    Journal article
    The University of Auckland Library

    The reported study was undertaken to investigate the micromechanical interactions that occur between sprayed seal (chip seal) layer materials in order to examine their relationship to the initiation of flushing. In particular, the deformation patterns of chip seal pavement samples with respect to lateral cyclic loading as well as the changes that occur to the distribution of air voids within a chip seal layer during loading were investigated. The effect of binder volume and air void volume on the development of flushing of the chip seal samples was also investigated. The reported study was based on laboratory testing of chip seal pavement samples (cores) that were obtained from in-service, flushed pavements in New Zealand. The cores, of 200-mm diameter and thicknesses ranging from 32.4 to 55.5 mm, were subjected to varying levels of lateral cyclic loading using a wheel tracking machine and the deformation that had occurred on the surface of the cores was measured. The cores were then scanned using a computed tomography (CT) scanner to examine changes that had occurred to the air void volume of the cores during the wheel tracking test, and the reductions in air void volume were compared with the quantity of flushing that was displayed on the cores. The cores were tested to determine the binder volumes in order to investigate how flushing development was affected by the ratio of binder volume and air void volume. The results from the analyses demonstrated that a strong correlation existed between flushing and air void volume reduction, where a larger reduction in air void volume directly corresponded to a higher amount of flushing. The deformation pattern of the cores indicated the likely state of stability of the chip seal structure, and the state of stability in turn indicated the best method of maintenance that was required for a flushed surface. The study findings demonstrated that the combination of wheel tracking and CT scanning is an extremely effective analysis method that can be used to determine the state of stability of a chip seal and to select the best maintenance treatment for pavement flushing.

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  • Special Issue on Structural Failures in Earthquakes

    Adam, J; Ingham, Jason (2013-12)

    Journal article
    The University of Auckland Library

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  • Earthquake Reconnaissance – Forensic Engineering on an Urban Scale

    GRIFFITH, MC; Ingham, Jason; WELLER, R (2010-09)

    Journal article
    The University of Auckland Library

    On 30 September 2009 a Richter magnitude 7.6 earthquake occurred approximately 50 km offshore from the Indonesian city of Padang on the west coast of Sumatra. As part of an AusAID initiative, the authors spent eight days onducting detailed structural assessments of damage to school buildings and medical/hospital buildings in the greater Padang region under the jurisdiction of the Australia – Indonesia Facility for Disaster Reduction (AIFDR). Approximately 300 school and 100 medical buildings were assessed during this time. The procedure used for this ‘forensic engineering’ task on an urban scale, rather than individual building scale, is described. From the data collected, the authors were able to identify common structural defects as well as deduce systemic defi ciencies in the overall design and construction process for the Padang region, with a summary of these observations presented.

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  • Retrofit techniques for seismic improvement of URM buildings

    Goodwin, C; Tonks, G; Ingham, Jason (2011)

    Journal article
    The University of Auckland Library

    As highlighted by the 2010 Darfield earthquake, many older buildings, particularly those constructed from unreinforced masonry (URM), now require seismic improvement in order to withstand earthquake forces. There are many approaches and techniques to seismic improvement, the most common of which are outlined below and analysed in terms of the impact of each on the heritage and architectural value of the building. This review is intended as a continuation of an earlier article (Goodwin et al. 2009) which gave background information to furnish designers with information prior to considering seismic retrofit. This information included a simple process for determining the basic heritage value of a building and some guidelines for good building conservation practice. A heritage building is more than simply a collection of building materials. As buildings age, they become more permanent parts of local culture. They become associated with notable people; with the memories of the public; and places where important historic events occurred. They become unique, as buildings are simply no longer made the same way, and time provides them with characteristics that could never be designed into a new building1. Old buildings can become ‘heritage’, where they become important to the public rather than just to the owner and occupants; a recent example of this is the birdcage hotel in Figure 1. There is no line on one side of which lies ‘heritage’, and on the other ‘not heritage’; all old buildings will have some heritage value. The difficulty is in determining the degree of heritage value, and what is important and what is less important about a building.

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  • Residual strength assessment and destructive testing of decommissioned concrete bridge beams with corroded pretensioned reinforcement

    Rogers, Rhys; Wotherspoon, Liam; Scott, A; Ingham, Jason (2012)

    Journal article
    The University of Auckland Library

    Destructive tests were performed on 19 decommissioned pretensioned concrete bridge beams that had corroded pretensioned reinforcement. The beams were obtained from the 1969 Tiwai Point Bridge in Southland, New Zealand, which experienced chloride-induced corrosion caused by sea spray that resulted in the superstructure’s being decommissioned and removed in 2009. Destructive flexural testing results were compared with thorough nondestructive condition assessments and with post-test breakouts of reinforcement. The beams tested ranged from good-condition beams to those with severe corrosion in 4 of the 21 prestressed strands. The most severely corroded beam sustained 69% of the load of an equivalent good-condition beam. A proposed methodology for the assessment of the residual strength of beams with corroded pretensioned reinforcement was shown to provide an effective means of estimating the number of corroded strands that should be disregarded in the calculation of the residual strength.

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  • Predicting Seismic Retrofit Construction Cost for Buildings with Framed Structures Using Multi-Linear Regression Analysis

    Jafarzadeh, Reza; Wilkinson, Suzanne; Gonzalez, Vicente; Ingham, Jason; Amiri, G (2013-06-07)

    Journal article
    The University of Auckland Library

    Attempts to predict construction cost represent a problem of continual concern and interest to both practitioners and researchers. Such an attempt is presented here for the specific challenge of cost prediction when undertaking seismic retrofitting of existing structures. Using multilinear regression analysis, 14 independent variables were analyzed to develop parametric models for predicting the retrofit net construction cost (RNCC). Half of these variables have never previously been studied in the literature. The required data for this study were collected from 158 earthquake-prone public schools in Iran, each having a framed structure. The backward elimination (BE) regression technique was used to identify any variables that made a statistically significant contribution to the RNCC. The suitability of the BE technique for this identification was examined and demonstrated using a number of model-selection criteria. Rather surprisingly, building age and compliance with the earliest practiced seismic design code were found to be insignificant predictors of the RNCC. As reflected by the BE technique, the significant predictors were building total plan area, number of stories, structural type, seismicity, soil type, weight, and plan irregularity. The causal analysis performed between the RNCC and these variables showed that the first two variables have the greatest influence on the determination of the RNCC. The primary contribution to the construction industry is the introduction of a simple double-log cost-area model for predicting seismic retrofit construction cost. The introduced model enables engineering consultants, managers, and policy makers to simply predict this cost at the early planning and budgeting stage of seismic retrofit projects.

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  • Simplified indexes for the seismic assessment of masonry buildings: International database and validation

    Lourenço, PB; Oliveira, DV; Leite, JC; Ingham, Jason; Modena, C; da Porto, F (2013-12)

    Journal article
    The University of Auckland Library

    Heritage masonry buildings are particularly vulnerable to earthquakes because they are deteriorated and damaged, they were built with materials with low resistance, they are heavy and the connections between the various structural components are often insufficient. The present work details a simplified method of seismic assessment of large span masonry structures that was applied to a database of 44 monuments in Italy, Portugal and Spain, providing lower bound formulas for different simplified geometrical indexes. Subsequently, the proposed thresholds are validated with data from the 2010-2011 Canterbury earthquakes, which includes 48 stone and clay brick masonry churches. Finally, fragility curves that can be used to estimate the damage as a function of the peak ground acceleration (PGA) are also provided.

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  • In-field simulated seismic testing of as-built and retrofitted unreinforced masonry partition walls of the William Weir House in Wellington

    Derakhshan, Hossein; Dizhur, Dmytro; Lumantarna, Ronald; CUTHBERT, J; Griffith, Michael; Ingham, Jason (2010-04)

    Journal article
    The University of Auckland Library

    Unreinforced masonry (URM) partition walls of William Weir House in Wellington were subjected to out-of-plane forces to investigate the as-built wall characteristic behaviour. The lateral load resisting system of the 1932 reinforced concrete building was scheduled to undergo seismic strengthening, and due to the absence of reliable wall out-of-plane assessment data, consulting engineers adopted an experimental proof-testing approach. A team of student researchers from the University of Auckland tested four URM partition walls by subjecting the walls to out-of-plane uniform pressure applied by means of a system of airbags. The testing included two mid-storey and two top-storey URM partitions, which had developed prior minor structural cracks. The full-scale in-situ testing confi rmed that the precracked partitions had suffi cient strength to resist the current New Zealand seismic demand, and the experimental programme resulted in substantial fi nancial benefi ts for the client as none of the walls were identifi ed as demolition or strengthening candidates. In addition to the as-builtout-of-plane tests, two tests were conducted on partition walls retrofi tted using nearsurface-mounted (NSM) fi ber-reinforced polymer (FRP) strips. The results of the as-built and the retrofi tted wall testing are reported, the wall behaviour is evaluated against the current seismic demand and the assessment results are compared with the New Zealand Society for Earthquake Engineering (NZSEE) recommendations.

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  • Effects of interface material on the performance of free rocking blocks

    ElGawady, MA; Ma, Tsun Ming Quincy; Butterworth, John; Ingham, Jason (2010)

    Journal article
    The University of Auckland Library

    This paper presents the results of an experimental investigation on the rocking behavior of rigid blocks. Two types of test specimens have been tested, namely M and C types. Nine blocks of the M type and two blocks of the C type with different aspect ratios were tested with varying initial rotational amplitudes and with different materials at the contact interface, namely concrete, timber, steel, and rubber. The results showed that the interface material has significant influence on the free rocking performance of the blocks. Blocks tested on rubber had the fastest energy dissipation followed by concrete and timber bases, respectively. Analysis of the test results has shown that the energy dissipation in the case of tests on a rubber base is a continuous mechanism whereas in the case of tests on rigid bases, i.e. timber and concrete, energy dissipation is a discrete function. Finally, the rocking characteristics of the blocks were calculated using piecewise equations of motion and numerical analysis. It was possible to predict the correct free rocking amplitude response when a reliable value for the coefficient of restitution was used.

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  • Observations from the 2010/2011 Canterbury Earthquakes and Subsequent Experimental Pull-Out Test Program of Wall-to-Diaphragm Adhesive Connections

    Dizhur, Dmytro; Campbell, J; Schultz, A; Ingham, Jason (2013-04-01)

    Journal article
    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 façade 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 diaphragms. 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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  • An inventory of unreinforced load-bearing stone masonry buildings in New Zealand

    Giaretton, Marta; Dizhur, Dmytro; da Porto, F; Ingham, Jason (2014)

    Journal article
    The University of Auckland Library

    Almost all unreinforced stone masonry (URSM) buildings in New Zealand were constructed between 1860 and 1910, typically in regions where natural stone was sourced from local quarries, fields and rivers. These buildings form an important part of the country’s architectural heritage, but the performance of URSM buildings during earthquake induced shaking can differ widely due to many aspects related to the constituent construction materials and type of masonry wall cross-section morphology. Consequently, as a step towards gaining greater knowledge of the New Zealand URSM building stock and its features, an exercise was undertaken to identify and document the country-wide URSM building inventory. The compiled building inventory database includes: (i) general building information, such as address, building owner/tenant and building use; (ii) architectural configuration, such as approximate floor area, number of storeys, connection with other buildings, plan and elevation regularity; and (iii) masonry type, such as stone and mortar types, wall texture and wall cross-section morphology. From this exercise it is estimated that there is in excess of 668 URSM buildings currently in existence throughout New Zealand. A large number of these vintage URSM buildings require detailed seismic assessment and the implementation of seismic strengthening interventions in order to conserve and enhance this component of New Zealand’s cultural and national identity. The entire stock of identified buildings is reported in the appended annex (688 total), including 20 URSM buildings that were demolished following the Canterbury earthquake sequence.

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  • Detailed seismic assessment and improvement procedure for vintage flexible timber diaphragms

    Giongo, I; Wilson, A; Dizhur, Dmytro; Derakhshan, H; Tomasi, R; Griffith, MC; Quenneville, Pierre; Ingham, Jason (2014-06)

    Journal article
    The University of Auckland Library

    Currently there is little guidance available on an experimentally-validated detailed seismic assessment procedure for vintage flexible timber diaphragms such as are routinely encountered in New Zealand unreinforced masonry buildings. The results from recent testing of full-scale diaphragms are presented and interpreted with particular attention given to the definition of shear stiffness and shear strength values, whilst acknowledging that the recommendations derive from a small data set. References are provided to information previously published elsewhere to justify the theoretical framework adopted, and the procedure is linked to ASCE 41-13 for guidance regarding diaphragm scenarios that have not been studied by the authors. A procedure is provided to account for the effects on diaphragm response of supplementary stiffness due to masonry end walls. The performance of several diaphragms that were improved with either overlays or underlays is reported as potential proof-tested standard solutions. The assessment procedure is demonstrated by providing a mock worked example of a detailed diaphragm assessment.

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