212 results for Ingham, Jason, Conference item

  • Seismic restraints for clay brick URM parapets validated using shake-table testing

    Dizhur, Dmytro; Giaretton, M; Ingham, Jason (2017-01-09)

    Conference item
    The University of Auckland Library

    Unrestrained unreinforced clay brick masonry (URM) parapets are found atop of a large number of vintage URM buildings. Parapets are typically cantilevered wall structural elements that form decorative and ornamental features of the building facades or in case of building side parapets, form a fire barrier. Parapets are considered to be the most vulnerable element that is prone to out-of-plane collapse when subjected to earthquake induced shaking. Due to the elevated location and the extent of the parapets above the main street frontage and main building entrances, unrestrained parapets represent a major risk to passers-by or building occupiers trying to escape from the building during an earthquake. Numerous observations made following recent earthquakes suggested that URM parapets that were previously secured performed below expectations. Subsequently, a comprehensive shake-table campaign was undertaken on 13 full-scale solid clay brick URM parapets, nine of those where then retrofitted and subjected again to dynamic loading. The objective of the study reported herein was to conduct an experimental investigation and develop generic industry-accepted proof-tested retrofit solutions for securing of URM parapets, including steel brace, timber brace, vertical strong-backs and post-tensioning. Results and observations from the experimental study are presented herein.

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  • Force based model for straight FRP anchors exhibiting fibre rupture failure mode

    Del Rey Castillo, Enrique; Griffith, MC; Ingham, Jason (2016-12-14)

    Conference item
    The University of Auckland Library

    The use of Fibre Reinforced Polymer (FRP) materials as Externally Bonded Reinforcements (EBR) is an established technique for structural improvement of existing buildings. Nevertheless the technique features disadvantages, and premature FRP-to-concrete debonding has been commonly highlighted as one of the main problems, together with the difficulty to fully wrap the structural element when the structure presents complex geometries. FRP straight anchors are used to transfer the forces from the FRP sheet into the structural element, eliminating these two problems, but a comprehensive design method for FRP anchors has not yet been established despite the increased use and research on FRP anchors. An extensive experimental programme has been carried out as part of an on-going research project with the ultimate goal being the development of a design methodology to enable engineers to efficiently and reliably design FRP anchors. The influence of a number of parameters on the capacity of straight FRP anchors has been investigated in the research, but only the anchor size and the fanning angle of the fan portion are reported here. The model that defines the relationship between anchor size, fanning angle and the capacity of the anchor exhibiting fibre rupture is described.

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  • Seismic behaviour of metal duct connections in precast concrete panels

    Seifi, Pouya; Henry, Richard; Ingham, Jason (2017-01-09)

    Conference item
    The University of Auckland Library

    The seismic performance of grouted connections between precast concrete panels was questioned in New Zealand following the 2010/2011 Canterbury earthquakes. Inadequate connection detailing contributed to the failure of some panel connections, and recommendations for more robust detailing of grouted metal duct connections were published by the Structural Engineering Society of New Zealand. In the research reported here a set of experimental tests was conducted in order to evaluate the seismic behaviour of both previously used detailing and of currently-recommended detailing of precast concrete walls with grouted metal duct connections. A total of seven full-scale precast concrete walls were subjected to reverse cyclic in-plane lateral loading. The geometry and reinforcement detailing of the walls was based on a review of over 4800 constructed precast concrete panels in order to test realistic panel detailing. Various parameters such as the wall thickness, aspect ratio, axial load, number of layers of reinforcement, and the use of transverse reinforcement around the connections were included in the experimental programme. The tests confirmed that in-plane wall response was dominated by connection behaviour, with significant rocking at the wall-to-foundation interface. Failure was typically controlled by fracture of the vertical reinforcement at the connection. The existing connections performed adequately when subjected to in-plane cyclic loads, but performance was found to diminish as the axial load and the wall dimensions increased. The use of transverse confinement reinforcement around the grouted metal ducts was observed to improve the robustness of the reinforcement splice at large lateral drifts.

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  • In-plane testing of precast concrete wall panels with grout sleeves

    Seifi, Pouya; Henry, Richard; Ingham, Jason (2017-04-27)

    Conference item
    The University of Auckland Library

    Grouted connections are widely used to connect precast concrete wall panels to their foundations. Various forms of grouted inserts are utilised in different countries to provide a splice between the wall panel and the connection reinforcement. A commonly used coupler insert in New Zealand is grouted sleeve inserts. This type of inserts has a threaded portion on top of the insert to connect the panel reinforcement and a tube-shaped part for positioning and anchoring connection reinforcement using cementitious grout. The two concerns associated with this type of connections are thread slip and reinforcement pull-out from the grout when the inserted reinforcement is subjected to cyclic loads. Thread slip affects the panel stiffness and reduces the connection integrity, and reinforcement pull-out is an undesirable failure mode. In order to evaluate the force-displacement behaviour of connections with grouted sleeve connectors, two full-scale experiments were conducted with one wall panel being reinforced with a single layer of vertical reinforcing and the other wall panel being doubly reinforced. The geometry and detailing of the wall panels was based on a previously conducted review of over 4000 constructed precast concrete wall panels. The specimens were subjected to reverse in-plane cycle loads until failure of either the connection or the wall panel. The results of the experiments are discussed in this article.

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  • Evaluating designs on existing buildings using heritage evaluation framework

    Partington, D; Dizhur, Dmytro; Ingham, Jason; Egbelakin, T (2017-04-27)

    Conference item
    The University of Auckland Library

    New Zealand owes a significant portion of its unique culture to its built heritage. While design provisions introduced into New Zealand attempt to encourage the preservation of heritage buildings, due to the high cost of remediation coupled with a short deadline for completion, many earthquake prone buildings (EPBs) are ultimately being demolished. The Heritage Evaluation Framework (HEF) is a new multi-disciplinary decision-making tool that aims to guide proposed seismic retrofit designs by gathering inputs from all parties involved in a project and using them to evaluate a particular design against client???s expectations. This research aims to analyse the performance of the HEF in relation to its potential to evaluate the appropriateness of proposed strengthening designs on EPBs. Testing of the framework was conducted via interviews, site walkthroughs and regular meetings with the teams and clients of two live heritage retrofit projects. Results were then presented back to the project members where appropriate adjustments to the design could then be achieved for the following design. Results show that the HEF is reasonably capable of analysing conceptual designs and able to give useful feedback whilst encouraging early collaboration to each project???s design team.

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  • Empirical vulnerability assessment of reinforced concrete frame with masonry infill buildings in the Canterbury earthquake sequence

    Fikri, R; Dizhur, Dmytro; Ingham, Jason (2017)

    Conference item
    The University of Auckland Library

    During the 2010/2011 Canterbury earthquakes, Reinforced Concrete Frame with Masonry Infill (RCFMI) buildings were subjected to significant lateral loads. A survey conducted by Christchurch City Council (CCC) and the Canterbury Earthquake Recovery Authority (CERA) documented 10,777 damaged buildings, which included building characteristics (building address, the number of storeys, the year of construction, and building use) and post-earthquake damage observations (building safety information, observed damage, level of damage, and current state of the buildings). This data was merged into the Canterbury Earthquake Building Assessment (CEBA) database and was utilised to generate empirical fragility curves using the lognormal distribution method. The proposed fragility curves were expected to provide a reliable estimation of the mean vulnerability for commercial RCFMI buildings in the region.

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  • Nonlinear finite element modelling of unreinforced masonry walls with openings subjected to in-plane shear

    Allen, C; Masia, M; Page, A; Griffith, M; Ingham, Jason (2017)

    Conference item
    The University of Auckland Library

    This paper presents a numerical investigation into the behaviour of unreinforced clay brick masonry walls with window and door type openings, subjected to in-plane loads. Nonlinear finite element simulations of full scale walls experimentally tested at The University of Newcastle have been undertaken using the commercial finite element analysis software TNO DIANA. In this study, both continuum (total strain fixed-crack) and simplified micro-model (crack-shear-crush) nonlinear finite element modelling strategies have been employed and key parameters including force versus displacement curves, failure modes, and damage patterns have been compared to experimental results.

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  • The development of Mobile Field Laboratory and hybrid testing facility at NZNEES@Auckland

    Ma, Tsun Ming Quincy; Omenzetter, Piotr; Ingham, Jason; Butterworth, John; Pender, Michael (2008)

    Conference item
    The University of Auckland Library

    Since the establishment of the NZNEES@Auckland node in 2006, developments have transformed the Auckland node from an end user portal to a research contributing facility. The New Zealand Network for Earthquake Engineering Simulations (NZNEES) was formed with the intention to act as a vehicle to interface with other similar networks overseas and allow New Zealand researchers to participate equally in the new global forum. NZNEES aims to facilitate collaborations with likeminded experts worldwide and access of state-of-the-art experimental and computational resources. This paper reviews two of the Auckland node???s highlights, the capabilities of the Mobile Field Laboratory (MFL) and the distributed hybrid testing setup. The MFL take advantage of Auckland???s access to buildings earmarked for destruction to conduct nonlinear tests on in-situ structural and geotechnical systems. A high speed satellite connection provides real time teleparticipation and teleoperation access of the MFL for remote researchers worldwide. Moreover, the NZNEES@Auckland node is equipped with a distributed hybrid testing setup that is compatible with setups found in United States and United Kingdom. NZNEES is already actively participating in coordinated studies with NEES@UCDAVIS, UK-NEES and NCREE. Examples of recent projects are presented to illustrate the current capabilities.

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  • In-Situ Testing of a Post Tensioned Seismically Retrofitted Full Scale Unreinforced Masonry Chimney

    McCauley, J; Ingham, Jason; Dizhur, Dmytro (2017-04-27)

    Conference item
    The University of Auckland Library

    Unreinforced masonry (URM) domestic chimneys are highly vulnerable and potentially earthquake prone building elements that represent a hazard to life inside and outside the buildings that they are located on. In addition, past New Zealand earthquakes have resulted in a large number of insurance claims relating to the damage associated with URM chimney failures. As part of ongoing research to establish a database of New Zealand URM chimneys, a statistical survey was conducted in Dunedin and Auckland. Key details and findings are provided from the 910 surveyed chimneys. Currently there is limited experimental research that has been undertaken on cost-effective retrofit techniques that increase the seismic resilience of domestic URM chimneys. In order to increase the pool of knowledge, a post-tensioned (PT) retrofit was experimentally field tested on an old full-scale URM chimney. Findings specific to the tested URM chimney showed a 2.6 times increase in the capacity of the retrofitted URM chimney.

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  • Damage observations following the MW 7.8 2016 Kaikoura earthquake

    Dizhur, Dmytro; Giaretton, M; Ingham, Jason (2017-06-12)

    Conference item
    The University of Auckland Library

    On 14 November 2016 a magnitude Mw 7.8 earthquake struck the upper South Island of New Zealand with effects also being observed in the capital city, Wellington. The affected area has low population density but is the largest wine production region in New Zealand and also hosts the main national highway and railway routes connecting the country???s three largest cities of Auckland, Wellington and Christchurch, with Marlborough Port in Picton providing connection between the South and North Islands. These transport facilities sustained substantial earthquake related damage, causing major disruptions. Thousands of landslides and multiple new faults were counted in the area. The winery facilities and a large number of commercial buildings and building components (including brick masonry veneers, historic masonry construction, and chimneys), sustained damage due to the strong vertical and horizontal acceleration. Presented herein are field observations undertaken the day immediately after the earthquake, with the aim to document earthquake damage and assess access to the affected area.

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  • Comparison between predicted URM wall out-of-plane strength based capacity and in situ proof test results

    Walsh, K; Dizhur, Dmytro; Giongo, I; Derakhshan, H; Ingham, Jason (2017-06-05)

    Conference item
    The University of Auckland Library

    Unreinforced masonry (URM) building construction is prominent in the form of load-bearing, partition, and infill walls. Significant out-of-plane (OOP) failures of URM walls often occur during moderate and severe earthquake shaking and such walls are often identified in structural engineering assessments as being amongst the most vulnerable elements to OOP demands, especially earthquakes. For undamaged, in situ wall conditions where material properties are known and boundary conditions reflect idealised conditions assumed in analytical predictive models, these predictive models are easily applied, although the accuracy of the model outputs may still not be well understood. Furthermore, when in situ conditions do not reflect idealised conditions assumed in analytical predictive models, engineers are often uncertain as to which analytical models and inputs are most appropriately applied. Hence, an analytical campaign was undertaken to provide specific examples for structural engineering practitioners assessing the OOP seismic behaviour of URM walls, and the predictive results reported herein were compared to previously reported experimental results of eighteen tests on existing URM walls performed in situ. The considered wall configurations represented a variety of geometries, boundary conditions, pre-test damage states, and material properties. The average ratio and associated coefficient of variation (CV) of predicted strengths to measured strengths were determined to be 0.84 (CV 0.56) and 0.93 (CV 0.25) for the ???unbounded??? and ???bounded??? wall conditions, respectively, and corresponding recommendations for analytical assessment were made for practicing engineers.

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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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  • Unbonded Prestressed Panel Tendon Stresses at In-Plane Nominal Flexural Strength

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

    Conference item
    The University of Auckland Library

    A series of in-plane tests on post-tensioned concrete wall panels with unbonded tendons are described. These tests were used to verify that tendon stresses at nominal flexural strength can be accurately predicted for concrete walls using an equation previously developed for post-tensioned concrete masonry walls. Testing showed that the equation gives more accurate prediction of tendon stress than current design methods used in New Zealand. A secondary objective was to examine the accuracy of ???true??? predictions of wall performance obtained by finite element analysis. Predictions of wall forcedisplacement response, tendon stress increase and concrete strain generally matched experimental data with acceptable accuracy. The experimental response of some walls was significantly influenced by the existence of a bedding layer with low stiffness, which could not be accurately modelled.

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  • Monotonic testing of unreinforced and GFRP-retrofitted masonry walls prone to shear failure in an earthquake

    Mahmood, Hamid; Russell, Alistair; Ingham, Jason (2008)

    Conference item
    The University of Auckland Library

    A research programme has been initiated in New Zealand to address concerns regarding the seismic performance of New Zealand???s unreinforced masonry (URM) building stock. As a component of this programme, monotonic in-plane shear (diagonal compression) tests were conducted on URM wallettes to simulate the commonly observed diagonal shear failure of in-plane walls in an earthquake. In total, four wallettes were tested, three of which were retrofitted with various configurations of GFRP strips. The unretrofitted wallette failed in a brittle manner. The retrofitted wallettes exhibited a more ductile behaviour. Significant increases in wallette strength and pseudo-ductility were achieved by the application of GFRP.

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  • Performance of masonry buildings during the 2010 Darfield (New Zealand) earthquake

    Ismail, N; Griffith, M; Ingham, Jason (2011-06-05)

    Conference item
    The University of Auckland Library

    The M7.1 Darfield earthquake shook the town of Christchurch (New Zealand) in the early morning on Saturday 4th September 2010 and caused damage to a number of heritage unreinforced masonry buildings. No fatalities were reported directly linked to the earthquake, but the damage to important heritage buildings was the most extensive to have occurred since the 1931 Hawke???s Bay earthquake. In general, the nature of damage was consistent with observations previously made on the seismic performance of unreinforced masonry buildings in large earthquakes, with aspects such as toppled chimneys and parapets, failure of gables and poorly secured face-loaded walls, and in-plane damage to masonry frames all being extensively documented. This report on the performance of the unreinforced masonry buildings in the 2010 Darfield earthquake provides details on typical building characteristics, a review of damage statistics obtained by interrogating the building assessment database that was compiled in association with post-earthquake building inspections, and a review of the characteristic failure modes that were observed.

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  • Studies on the material properties of the Aurora Tavern, Auckland

    Lumantarna, R; Dizhur, D; Liu, P; Ingham, Jason (2011-04-14)

    Conference item
    The University of Auckland Library

    The Aurora Tavern was one example of many heritage unreinforced masonry (URM) buildings in New Zealand, and therefore like other existing URM buildings, this hotel was vulnerable to damage should a moderate magnitude earthquake occur. Refurbishment and strengthening work was being implemented on the building, during which in-situ testing was performed to investigate the building???s material properties. The URM materials in the Aurora Tavern were generally in poor condition, and water ingress was observed at various locations in the building. In-situ deformability tests and bed joint shear tests were conducted on-site to determine the masonry stiffness and the mortar bed joint shear strength respectively. In addition, individual brick units and irregular mortar samples were extracted for compression testing in the laboratory. Laboratory mortar compression tests and in-situ deformability tests showed that the mortar compressive strength and masonry Modulus of Elasticity were low. However, the brick compressive and mortar bed joint shear strengths were comparable to those of other buildings that were previously investigated by the research team.

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  • Implications of the 2010 Darfield (Christchurch, NZ) earthquake for Australia ??? are we ready?

    Griffith, MC; Ingham, Jason; Moon, L (2010)

    Conference item
    The University of Auckland Library

    The 2010 Darfield earthquake is the largest earthquake on record to have occurred within 40 km of a major city and not cause any fatalities. In this paper the authors have reflected on their experiences in Christchurch following the earthquake with a view to what worked, what didn???t, and what lessons can be learned from this for the benefit of Australian earthquake preparedness. Owing to the fact that most of the observed building damage occurred in Unreinforced Masonry (URM) construction, this paper focuses in particular on the authors??? experience conducting rapid building damage assessment during the first 72 hours following the earthquake and more detailed examination of the performance of unreinforced masonry buildings with and without seismic retrofit interventions.

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  • Performance of Unreinforced Masonry Structures in the 2010/2011 Canterbury Earthquake Sequence

    Moon, LM; Griffith, MC; Dizhur, Dmytro; Ingham, Jason (2012-09-24)

    Conference item
    The University of Auckland Library

    Following the magnitude 6.3 aftershock in Christchurch, New Zealand, on 22 February 2011, a number of researchers were sent to Christchurch as part of the New Zealand Natural Hazard Research Platform funded ???Project Masonry??? Recovery Project. Their goal was to document and interpret the damage to the masonry buildings and churches in the region. Approximately 650 unreinforced and retrofitted clay brick masonry buildings in the Christchurch area were surveyed for commonly occurring failure patterns and collapse mechanisms. The entire building stock of Christchurch, and in particular the unreinforced masonry building stock, is similar to that in the rest of New Zealand, Australia, and abroad, so the observations made here are relevant for the entire world.

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  • Report on the ???Project Masonry??? recovery project

    Dizhur, D; Ingham, Jason (2012-11-02)

    Conference item
    The University of Auckland Library

    As part of the ???Project Masonry??? Recovery Project funded by the New Zealand Natural Hazards Research Platform, commencing in March 2011, an international team of researchers was deployed to document and interpret the observed earthquake damage to masonry buildings and to churches as a result of the 22nd February 2011 Christchurch earthquake. The study focused on investigating commonly encountered failure patterns and collapse mechanisms. A brief summary of activities undertaken is presented, detailing the observations that were made on the performance of and the deficiencies that contributed to the damage to approximately 650 inspected unreinforced clay brick masonry (URM) buildings, to 90 unreinforced stone masonry buildings, to 342 reinforced concrete masonry (RCM) buildings, to 112 churches in the Canterbury region, and to just under 1100 residential dwellings having external masonry veneer cladding. Also, details are provided of retrofit techniques that were implemented within relevant Christchurch URM buildings prior to the 22nd February earthquake. In addition to presenting a summary of Project Masonry, the broader research activity at the University of Auckland pertaining to the seismic assessment and improvement of unreinforced masonry buildings is outlined. The purpose of this outline is to provide an overview and bibliography of published literature and to communicate on-going research activity that has not yet been reported in a complete form.

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  • Seismic Performance of Masonry Buildings in the Christchurch Earthquakes 2010-2011: A Progress Report

    Moon, LM; Dizhur, D; Ingham, Jason; Griffith, MC (2012-12-07)

    Conference item
    The University of Auckland Library

    Following the Christchurch earthquake of 22 February 2011 a number of researchers were sent to Christchurch, New Zealand to document the damage to masonry buildings as part of ???Project Masonry???. Coordinated by the Universities of Auckland and Adelaide, researchers came from Australia, New Zealand, Canada, Italy, Portugal and the US. The types of masonry investigated were unreinforced clay brick masonry, unreinforced stone masonry, reinforced concrete masonry, residential masonry veneer and churches; masonry infill was not part of this study. This paper focuses on the progress of the unreinforced masonry (URM) component of Project Masonry. To date the research team has completed raw data collection on over 600 URM buildings in the Christchurch area. The results from this study will be extremely relevant to Australian cities since URM buildings in New Zealand are similar to those in Australia.

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