322 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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  • Vulnerability analysis of unreinforced masonry churches (EQC 14/660) - Final Report

    Goded, T; Cattari, S; Lagomarsino, S; Giovinazzi, S; Ingham, Jason; Marotta, A; Liberatore, D; Sorrentino, L; Ottonelli, D; Pinna, M; Clark, W (2016-06-30)

    Report
    The University of Auckland Library

    We undertake the first (to our knowledge) seismic vulnerability method specifically designed for New Zealand Unreinforced Masonry (URM) churches. The vulnerability index (VI) methodology developed by Lagomarsino et al. (2003) for European churches and other monumental buildings has been the basis for our work. The technique entails a macroseismic approach which is based on the use of vulnerability curves to correlate the postseismic damage grade of the building to the shaking intensity experienced, using a discrete probabilistic distribution. The method has been redefined, with a new set of parameters and modifiers specifically created for New Zealand URM churches. This has been done by analysing the damage caused to 48 URM churches in the Canterbury region during the 2010–2011 Canterbury earthquake sequence. This report shows the main achievements obtained during this project, funded by the Earthquake Commission (reference 14/660, January 2014-June 2016), which include: (a) the structural data compilation of a wider stock of 297 URM churches spread within New Zealand; (b) a specific typological classification for New Zealand unreinforced masonry (URM) churches; (c) a damage survey form for URM churches; (d) a macroseismic method to obtain the seismic vulnerability of URM churches using VI modifiers that have been developed specifically for New Zealand URM churches, using the damage data from the Canterbury earthquakes; and (e) the development of seismic scenarios for the URM churches in Wellington, Auckland and Dunedin, using the new parameters developed within this project. The typological analysis of the New Zealand URM churches justified the need to develop a method specifically created for this country, as results show the great differences in typologies to European churches, with very simple architectural designs and a majority of one nave churches in New Zealand. The method has been applied to three cities in New Zealand, with very different seismic activity, from low (Auckland) to intermediate (Dunedin) and high (Wellington). Differences in the results due to the different characteristic scenarios show the need to develop specific scenarios for each city / region. This project is seen as a first step towards the qualification of all the historical buildings in the country, in order to preserve New Zealand’s cultural and historical heritage. Future work identified includes (a) the development of seismic scenarios for the URM churches in the rest of New Zealand, (b) addition of site effects to the seismic scenarios, to account for local differences in intensities experienced in each church, to be developed for the entire set of URM churches in the country, (c) development of a more sophisticated method based on the mechanical approach that analyses the structural behaviour of individual components of the building (macroelements) and (d) the addition of other buildings part of the cultural heritage in New Zealand.

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  • Assessment of shear stress limits for high-strength concrete bridge beams

    Al-Ani, M; Rogers, R; Ingham, Jason (2012-11)

    Report
    The University of Auckland Library

    The design of concrete beams for shear loading is governed in New Zealand by the provisions of NZS 3101. The shear design provisions of NZS 3101 impose two limits on the permissible design shear capacity, including a maximum shear capacity of 8MPa. This 8MPa limit influences the efficiency of concrete beam design, and in particular the design of concrete bridge beams that have concrete compressive strengths greater than 40MPa. The validity of this limit was assessed through an examination of a number of other international design standards, statistical analyses using databases composed of all previous experimental testing of reinforced concrete (RC) and prestressed concrete (PC) beams, and results from an experimental investigation aimed at addressing deficiencies in the compiled databases. The research found that the limits in NZS 3101 are excessively conservative compared with the limits imposed in most other design standards. This observation was reinforced by analysis of the databases and results of the experimental investigation, which supported the need for a limit on the nominal design shear capacity but found that an absolute limit of 8MPa was overly restrictive. Alternative limits were proposed, and the absolute limit of 10MPa was found to provide improved design accuracy without compromising safety.

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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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  • Seismic analysis of in-plane loaded walls in unreinforced masonry buildings with flexible diaphragms

    Nakamura, Y; Derakhshan, H; Ingham, Jason; Griffith, MC (2014-12-01)

    Journal article
    The University of Auckland Library

    It is well recognised that the dynamic response of unreinforced masonry buildings with flexible timber diaphragms typically contains multiple dominant modes associated with the excitations of the diaphragms and the in-plane walls. Existing linear analysis methods for this type of structure commonly account for the multi-mode behaviour by assuming the independent vibrations of the in-plane loaded walls (in-plane walls) and the diaphragms. Specifically, the in-plane walls are considered to be rigid and the unmodified ground motion is assumed to be transmitted up the walls to the diaphragm ends. While this assumption may be appropriate for many low-rise unreinforced masonry buildings, neglecting the dynamic interaction between the diaphragms and the in-plane walls can lead to unreliable predictions of seismic demands. An alternative analysis approach is proposed in this paper, based on the mode properties of a system in which (1) the mass ratios between the diaphragms and the in-plane wall are the same at all levels, and (2) the periods of the diaphragms are the same at all levels. It is proposed that under these conditions, two modes are typically sufficient to obtain the peak seismic demands of the inplane walls in elastically responding low-rise regular buildings. The applicability of the two-mode analysis approach is assessed for more general diaphragm configurations by sensitivity analysis, and the limitations are identified. The two-mode approach is then used to derive a response modification factor, which may be used in conjunction with a linear static procedure in the seismic assessment of buildings with flexible diaphragms.

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  • Displacement-Based RC Column Assessment for a Case Study Interwar Building

    Walsh, KQ; Dizhur, Dmytro; Liu, P; Masoudi, M; Ingham, Jason (2016-04)

    Journal article
    The University of Auckland Library

    Following the devastating 1931 Hawke‘s Bay earthquake, commercial buildings in the Hawke‘s Bay, New Zealand region were rebuilt in mostly homogenous structural and architectural styles. Most were constructed of reinforced concrete (RC) two-way space frames in the Art Deco aesthetic popularised during the interwar time period. Although most Art Deco RC columns in Hawke‘s Bay have generally ductile detailing for their time period of construction, they are nonetheless often expected to be brittle, earthquake-prone components based on strength-based seismic assessments. The reported case study was intended to provide a displacement-based example for undertaking a seismic assessment of Art Deco RC columns while appropriately accounting for regional seismicity, material properties, building component interaction, column geometry, and reinforcement detailing, as a resource for professional structural engineers tasked with seismic assessments and retrofit designs for similar buildings.

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  • Economic impediments to successful seismic retrofitting decisions

    Egbelakin, T; Wilkinson, Suzanne; Ingham, Jason (2014)

    Journal article
    The University of Auckland Library

    Purpose – The purpose of this paper is to examine why building owners are often reluctant to adopt adequate mitigation measures despite the vulnerability of their buildings to earthquake disasters, by exploring the economic-related barriers to earthquake mitigation decisions. Design/methodology/approach – A case study research method was adopted and interviews chosen as the method of data collection. Findings – Critical economic-related impediments that inhibited seismic retrofitting of earthquake-prone buildings were revealed in this study. Economic-related barriers identified include perception about financial involvement in retrofitting, property market conditions, high insurance premiums and deductibles, and the high cost of retrofitting. The availability of financial incentives such as low interest loans, tax deductibles, the implementation of a risk-based insurance premium scale and promoting increased knowledge and awareness of seismic risks and mitigation measures in the property market place are likely to address the economic-related challenges faced by property owners when undertaking seismic retrofitting projects. The provision of financial incentives specifically for seismic retrofitting should be introduced in policy-implementation programme tailored to local governments’ level of risks exposure and available resources. Practical implications – The recommendations provided in this study suggest strategies and answers to questions aimed at understanding the types of incentives that city councils and environmental hazard managers should focus on in their attempt to ensure that property owners actively participate in earthquake risk mitigation. Originality/value – This paper adopts a holistic perspective for investigating earthquake risk mitigation by examining the opinions of the different stakeholders involved in seismic retrofit decisions.

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  • Assessment of timber floor diaphragms in historic unreinforced masonry buildings

    Wilson, AW; QUENNEVILLE, PJH; Ingham, Jason (2011)

    Conference item
    The University of Auckland Library

    Unreinforced masonry (URM) buildings outside of Europe were typically constructed with rigid clay brick perimeter walls, and comparatively flexible timber floor diaphragms. URM construction represents the predominant architectural heritage of many nations but the preservation of these buildings in seismically active regions is threatened due their well established inadequacy to withstand earthquakes. Timber floor diaphragms are widely recognized to have significant impact on the overall seismic response of URM structures, and the accurate assessment of diaphragms is therefore crucial during the seismic assessment and retrofit of URM buildings. NZSEE (2006) - Assessment and improvement of the structural performance of buildings in earthquakes, and ASCE 41-06 (2007) – Seismic rehabilitation of existing buildings represent the current state-of-the-art in seismic assessment but the validity of the procedures associated with timber diaphragm performance remains uncertain, and a review of their application and accuracy is required. As part of a wider research program, a series of full-scale diaphragm tests were performed to generate the much needed data to critique the current desktop procedures. In this contribution, the NZSEE and ASCE 41-06 procedures are used to predict full-scale diaphragm performance and are compared against experimentally determined values. It was found that inconsistency exists between the two assessment documents with considerable differences found in strength, stiffness and ductility predictions. The procedures published in NZSEE and ASCE 41-06 require updated and representative values, and to include provisions to address the highly orthotropic nature of diaphragms that was identified from testing. It is also believed that these documents should be harmonized to ensure that transparency and consistency exists between international assessment procedures.

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  • Earthquake-Damaged Unreinforced Masonry Building Tested In-Situ

    Dizhur, Dmytro; Derakhshan, H; Lumantarna, R; Ingham, Jason (2010-09)

    Journal article
    The University of Auckland Library

    In December 2007 a magnitude 6.8 earthquake had an epicentre located approximately 50 km from the city of Gisborne, New Zealand. This earthquake caused damage to a number of buildings in Gisborne, and in particular, to numerous unreinforced masonry buildings. One such building was damaged to the extent that significant post-earthquake repairs were necessary, and partial removal of two of the building’s gable ended walls was required. This reconstruction provided an opportunity for a team of researchers from the University of Auckland to conduct field tests on the building, allowing comparison with companion testing that had previously been undertaken in a laboratory setting. This field testing involved the extraction of clay brick and mortar samples, in-situ bed joint shear tests, diagonal shear tests on samples extracted from the gabled walls, an in-situ in-plane shear test and out-of-plane testing of a gable ended wall both in the as-built condition and after the installation of a near-surface mounted (NSM) carbon fibre reinforced polymer (CFRP) retrofit solution. Testing confirmed that the boundary conditions in real buildings can significantly affect experimental response, with vertical restraint resulting in a large increase in out-of-plane load capacity, and also confirmed that the near-surface mounted FRP solution is an excellent low invasive option for seismic strengthening of unreinforced masonry walls. Details of the history of the building, and the methods used to undertake the field testing are reported, and experimental results are presented.

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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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  • Trends in the Architectural Characterisation of Unreinforced Masonry in New Zealand

    Russell, Alistair; Ingham, Jason (2008)

    Conference item
    The University of Auckland Library

    This paper identifies seven typologies for characterising New Zealand’s unreinforced masonry (URM) building stock. This enables a better understanding of what typical behaviour to expect when assessing heritage URM buildings. Distinctions between typologies are drawn largely on the basis of building height and the geometry of the building’s footprint.

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  • Historical development and observed performance of unreinforced clay brick masonry cavity walls

    Dizhur, Dmytro; Jiang, X; Qian, C; Almesfer, N; Ingham, Jason (2015-04-01)

    Journal article
    The University of Auckland Library

    An informative background to unreinforced masonry (URM) cavity walls is presented in sequence of historical development, typical construction details, and observed damage in major past earthquakes. From URM building surveys it was found that URM cavity walls make up approximately 40% of URM construction in New Zealand, with the remainder having solid interconnected multi-leaf walls. Based on a detailed review of 125 URM cavity wall buildings that were damaged during the 2010/2011 Canterbury earthquakes, it was concluded that unretrofitted URM cavity walls generally suffered irreparable damage due to the lack of effective wall restraint and weak mortar strength . The majority (approximately ¾) of the observed damage to URM cavity wall construction was a result of out-of-plane type wall failures. Three types of out-of-plane wall failures that were commonly observed in cavity walls were: (1) Cantilever type failure with the entire top section of a wall or building façade collapsing (36%); (2) One-way bending type failure, which tended to occur in long spanning walls and/or walls without side support (7%); (3) Two-way bending type failure, which tended to occur in walls restrained at all boundaries (57%). In-plane damage of URM cavity walls was less widely observed (approximately ¼) compared to out-of-plane damage, and commonly included diagonal shear cracking in piers, spandrels and walls as well as to a lesser extent shear sliding on mortar bed joints or between building storeys. It was found that the original cavity wall ties were typically corroded due to moisture ingress. These badly corroded wall ties further diminished the lateral loadbearing capacity of cavity walls and their resistance to shear and flexural actions. It was identified that the most commonly encountered ties were horse-toe steel wire ties, having a cross-section that was typically found to be significantly deteriorated due to corrosion at the mortar bed joints. Pull-out of wall ties from mortar joints was observed.

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  • The 2014 South Napa earthquake and its relevance for New Zealand

    Galloway, B; Ingham, Jason (2015-04-01)

    Journal article
    The University of Auckland Library

    The South Napa earthquake occurred on Sunday, 24 August 2014 at 3.20 am local time at a depth of 10.7 km, having MW 6.0 and causing significant damage to unreinforced masonry (URM) buildings in the City of Napa and generating strong ground shaking in a region well known for its wine production. Parallels exist between the damage in past New Zealand earthquakes, particularly to unreinforced masonry buildings, and the disruption in the Marlborough region following the recent 2013 MW 6.5 Seddon earthquake. Furthermore, the event was the largest to have occurred in Northern California since the 1989 Loma Prieta earthquake 25 years earlier, and hence was an important event for the local community of earthquake researchers and professionals regarding the use of a physical and virtual clearinghouse for data archiving of damage observations. Because numerous URM buildings in the City of Napa had been retrofitted, there was significant interest regarding the observed performance of different retrofitting methods. Following a brief overview of the earthquake affected area and previous earthquakes to have caused damage in the Napa Valley region, details are provided regarding the characteristics of the 2014 South Napa earthquake, the response to the earthquake including placarding procedures and barricading, and more specific details of observed building and non-structural damage. Aspects of business continuity following the South Napa earthquake are also considered. One conclusion is that in general the seismic retrofitting of URM buildings in the Napa region proved to be very successful, and provides an important benchmark as New Zealand begins to more actively undertake seismic assessment and retrofitting of its earthquake prone building stock. It is also concluded that there are sufficient similarities between New Zealand and California, and a rich network of contacts that has developed following the hosting of many US visitors to New Zealand in conjunction with the 2010/2011 Canterbury earthquakes, that it is sensible for the New Zealand earthquake engineering community to maintain a close focus on ongoing earthquake preparedness and mitigation methods used and being developed in USA, and particularly in California.

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  • URM bearing wall building seismic risk mitigation on the west coast of the United States: A review of policies and practices

    Paxton, B; Turner, F; Elwood, Kenneth; Ingham, Jason (2015-01-01)

    Journal article
    The University of Auckland Library

    Unreinforced masonry (URM) buildings are the most common target for seismic risk mitigation programmes, due to their long history of poor seismic performance. While seismic risk mitigation must make use of sound engineering methodologies, good public policy is at the heart of successful programmes. Past URM seismic risk mitigation efforts on the west coast of the United States are summarized herein, as valuable insights have been gained from both successful and unsuccessful programmes. Programme details such as compliance deadlines, retrofit design techniques, and retrofit/demolition rates are provided for cities throughout California, Oregon and Washington states, and the overall observed effectiveness of mandatory versus non-mandatory seismic strengthening programmes is discussed.

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  • The 2014 South Napa Earthquake and its relevance for New Zealand

    Galloway, B; Ingham, Jason (2015-01-01)

    Journal article
    The University of Auckland Library

    The South Napa earthquake occurred on Sunday, 24 August 2014 at 3.20 am local time at a depth of 10.7 km, having MW 6.0 and causing significant damage to unreinforced masonry (URM) buildings in the City of Napa and generating strong ground shaking in a region well known for its wine production. Parallels exist between the damage in past New Zealand earthquakes, particularly to unreinforced masonry buildings, and the disruption in the Marlborough region following the recent 2013 MW 6.5 Seddon earthquake. Furthermore, the event was the largest to have occurred in Northern California since the 1989 Loma Prieta earthquake 25 years earlier, and hence was an important event for the local community of earthquake researchers and professionals regarding the use of a physical and virtual clearinghouse for data archiving of damage observations. Because numerous URM buildings in the City of Napa had been retrofitted, there was significant interest regarding the observed performance of different retrofitting methods. Following a brief overview of the earthquake affected area and previous earthquakes to have caused damage in the Napa Valley region, details are provided regarding the characteristics of the 2014 South Napa earthquake, the response to the earthquake including placarding procedures and barricading, and more specific details of observed building and non-structural damage. Aspects of business continuity following the South Napa earthquake are also considered. One conclusion is that in general the seismic retrofitting of URM buildings in the Napa region proved to be very successful, and provides an important benchmark as New Zealand begins to more actively undertake seismic assessment and retrofitting of its earthquake prone building stock. It is also concluded that there are sufficient similarities between New Zealand and California, and a rich network of contacts that has developed following the hosting of many US visitors to New Zealand in conjunction with the 2010/2011 Canterbury earthquakes, that it is sensible for the New Zealand earthquake engineering community to maintain a close focus on ongoing earthquake preparedness and mitigation methods used and being developed in USA, and particularly in California.

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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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  • 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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  • Bridge Knee Joint with Headed Reinforcement

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

    Conference item
    The University of Auckland Library

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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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