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O'Connor, Alan
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O'Connor, Alan
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O'Connor, Alan
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Now showing 1 - 10 of 35
- PublicationProbabilistic analysis of potential impact of extreme weather events on infrastructures(2014-08-29)
; ; In recent years, a variety of extreme weather events, including droughts, rain induced landslides, river floods, winter storms, wildfire, and hurricanes, have threatened and damaged many different regions across Europe and worldwide. These events can have devastating impact on critical infrastructure systems. The 7th Framework RAIN project will address these issues, involving partners from Ireland, Belgium, Germany, Finland, Italy, Netherlands, Slovenia and Spain. In this project, the impact of critical infrastructure failure on society, on security issues and on the economy will be examined. Based on the impacts of the failures, quantifiable benefits (from a societal, security and economic standpoint) of providing resilient infrastructure will be identified. In this project, a means of quantifying the level of risk will be established, first due to single land transport mode failures, and second due to selected multi-mode-interdependent failure scenarios (e.g. failure of power stations result in failure of electrical train lines). This paper introduces the RAIN project and its goal of developing a methodology to create an advanced risk assessment procedure, including a probabilistic based approach, to derive a measurable indicator of risk.150 - PublicationProcedures for Calibration of Eurocode Traffic Load Model 1 for National Conditions(2012-09-07)
; ; Since April 2010 Eurocode Load Model 1 (LM1) is the prescribed traffic load model to be employed in the design of highway bridges in the European Union (EU). Uniquely, the code permits member states to calibrate the load model, through the application of 'α-factors' to allow for national or regional conditions. Some countries with high volumes of very heavy traffic may find that they require α-factors in excess of unity whilst other less heavily trafficked road networks may require much lesser values. The importance of accurate calibration of the α-factors is clear from a safety and economic point of view. This paper describes procedures for calibration of α-factors using Weigh in Motion (WIM) data. WIM data allows classification of the traffic loads in individual countries, enabling the specific Gross Vehicle Weights (GVWs), axle loads and frequencies of heavy trucks to be taken into account. Simulations calibrated using this data, for a wide range of structural forms (i.e., influence lines, spans and numbers of lanes) and scenario types (i.e., free flowing, congested and mixed traffic conditions); allow comparison of the load effects generated by the site-specific traffic to those obtained when employing LM1. Statistical Extreme Value Distributions (EVDs) are fitted to simulated results to determine characteristic load effect values using the same methodology as was employed in the calibration of LM1 itself. Appropriate α adjustment factors are then determined to cater for variation in predicted characteristic extreme load effects on a network by network basis. Where α<1.0, the prescribed approach delivers significant savings by preventing unnecessary overdesign of bridges. On the other hand, for cases where α>1.0 it allows bridge designers to design bridges with adequate levels of safety.315 - PublicationTraffic Load Effect Forecasting for Bridges(International Association for Bridge and Structural Engineering, 2015-09-23)
; ; Traffic flows, as well as truck weights, increase with time. This must be taken into account in order to accurately assess traffic loading on bridges. The Eurocode Load Model 1 is used for the design of new bridges but a scaled down version of the model can be used for the assessment of existing bridges. This scaling is usually done by applying α–factors to the load model. The effect of traffic growth on these α–factors is assessed in this paper. Weigh-in-motion data from the Netherlands is used as the basis for traffic models which simulate year-on-year growth of both traffic flow and truck weights. A time-varying generalised extreme value distribution is then used to calculate the characteristic load effects and determine the α–factors. The effect of different traffic growth rates on these α–factors is then examined. It is found that an increase in truck weights has the most influence on the α–factors but that increased flow also has a significant effect.310 - PublicationConsidering Traffic Growth in Characteristic Bridge Load Effect CalculationsTraffic volumes and weights increase with time. This is an important consideration in order toaccurately calculate characteristic load effects for the design and assessment of bridges. A modeling approach is presented which can allow for future growth of truck weights and volumes when assessing truck loading on bridges. Weigh-in-motion data from a site in the Netherlands is used as an example to demonstrate traffic growth at that site. In assessing the effect of growth on characteristic load effects, different growth rates for both truck volumes and truck weights are considered. It is found that growth of truck weights has considerablymore influence although growth in truck volumes also has a significant effect.
188 - PublicationTRUSS, a European Innovative Training Network Dealing with the Challenges of an Aging Infrastructure Network(NDT.net, 2019-04-01)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Inspections and maintenance of infrastructure are expensive. In some cases, overdue or insufficient maintenance/monitoring can lead to an unacceptable risk of collapse and to a tragic failure as the Morandi bridge in Genoa, Italy, on 14th August 2018. An accurate assessment of the safety of a structure is a difficult task due to uncertainties associated with the aging and response of the structure, with the operational and environmental loads, and with their interaction. During the period from 2015 to 2019, the project TRUSS (Training in Reducing Uncertainty in Structural Safety) ITN (Innovative Training Network), funded by the EU H2020 Marie Curie-Skłodowska Action (MSCA) programme, has worked towards improving the structural assessment of buildings, energy, marine, and transport infrastructure. Fourteen Early Stage Researchers (ESRs) have been recruited to carry out related research on new materials, testing methods, improved and more efficient modelling methods and management strategies, and sensor and algorithm development for Structural Health Monitoring (SHM) purposes. This research has been enhanced by an advanced program of scientific and professional training delivered via a collaboration between 6 Universities, 1 research institute and 11 companies from 5 European countries. The high proportion of companies participating in TRUSS ITN has ensured significant industry expertise and has introduced a diverse range of perspectives to the consortium on the activities necessary to do business in the structural safety sector.115 - PublicationLong life bridges(2014-04-17)
; ; The single market is at the core of what the European Union (EU) represents and for Europe in particular, the single market depends on an effective transportation system. However, much of the EU's stock of an estimated 1 million bridges are old and have deteriorated over time. Many of these structures will soon need replacement or maintenance/intervention strategies to optimize their remaining service life. The Long Life Bridges project is a European 7th Framework-funded project that is using advanced analysis techniques to extend the lives of bridges, allowing them to be kept in service longer than would otherwise be possible. Research is centred on the specific considerations of bridge loading and dynamics, life cycle evaluation and fatigue evaluation. It is being carried out by a consortium consisting of two small/medium enterprises and two universities that bring together expertise in the fields of structural assessment, probabilistic analysis and risk quantification from both academic and industrial backgrounds.107 - PublicationTRUSS, a European innovative training network dealing with the challenges of an aging infrastructure network(2018-11-12)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Inspections and maintenance of infrastructure are expensive. In some cases, overdue or insufficient maintenance/monitoring can lead to an unacceptable risk of collapse and to a tragic failure as the Morandi bridge in Genoa, Italy, on 14th August 2018. An accurate assessment of the safety of a structure is a difficult task due to uncertainties associated with the aging and response of the structure, with the operational and environmental loads, and with their interaction. During the period from 2015 to 2019, the project TRUSS (Training in Reducing Uncertainty in Structural Safety) ITN (Innovative Training Network), funded by the EU H2020 Marie Curie-Skłodowska Action (MSCA) programme, has worked towards improving the structural assessment of buildings, energy, marine, and transport infrastructure. Fourteen Early Stage Researchers (ESRs) have been recruited to carry out related research on new materials, testing methods, improved and more efficient modelling methods and management strategies, and sensor and algorithm development for Structural Health Monitoring (SHM) purposes. This research has been enhanced by an advanced program of scientific and professional training delivered via a collaboration between 6 Universities, 1 research institute and 11 companies from 5 European countries. The high proportion of companies participating in TRUSS ITN has ensured significant industry expertise and has introduced a diverse range of perspectives to the consortium on the activities necessary to do business in the structural safety sector.169 - PublicationDirect and Probabilistic Interrelationships between Half-Cell Potential and Resistivity Test Results for Durability Ranking(2012-07-21)
; ; Tests related to durability studies on structures often feature half-cell potential and resistivity data. An approximately linear relationship between half-cell potential testing and resistivity data has been discussed and well-researched. In spite of criticisms related to environmental sensitivity of resistivity tests it remains as a popular choice for investigations into durability of structures. This paper investigates the correlation between half-cell potentials and resistivity tests on reinforced concrete from field data from tests on six bridges. The empirical interrelationships from the six bridges with widely varying environmental exposure conditions and the variation of such interrelationships are observed. Similar investigations are carried out on different elements of bridges. The paper then discusses problems related to the interpretation and practical application of correlations carried out on absolute values and advocates the use of statistical measures obtained from test data. The percentile correlations are observed to be helpful when considering exceedances of different threshold values. A customised use of such data in an empirically correlated probabilistic format with can be useful in durability ranking and infrastructure maintenance management. The studies presented in this paper emphasize the advantages of using probabilistic formats over traditional formats when interpreting or quantitatively establishing field relationships between half-cell potential and resistivity data. The ability of this empirically correlated probabilistic format to support structure-specific thresholds of serviceability limit states is discussed. The need for a shared repository for the improvement of accuracy of such correlations and for the use of such correlations as a surrogate for other structures is emphasized.221 - PublicationSustainable Maintenance and Analysis of Rail Transport Infrastructure (SMART rail)(2012-09-07)
; ; ; Safe and efficient transport infrastructure is a fundamental requirement to facilitate and encourage the movement of goods throughout the European Union. Currently there are in the region of 215,000km of railway lines in the EU. Many of these were not built to conform to modern design standards and suffer from poor maintenance strategies. The SMART Rail project brings together experts in the field of rail transport infrastructure from across Europe to develop state of the art inspection, monitoring and assessment techniques. This will allow rail operators to manage ageing infrastructure in a cost effective and environmentally friendly manner. RODIS will develop models to greatly improve the ability of the track owners to predict the future condit ion of the ir infrastructure. A probability based framework will be developed for optimised whole life management of the infrastructural elements. This will encompass not just bridges but all aspects of rail infrastructure such as track susceptibility to settlement and the stability of slopes and embankments. Sensor information will be incorporated into the structural safety models allowing real time analysis to be performed. This will enable the rate of deterioration of the infrastructure elements to be determined and allow implementation of an optimised and cost effective intervention strategy before any significant damage occurs.120