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Full-Text Articles in Engineering
The Effect Of Truck Permitting Policy On Us Bridge Loading, Eugene J. Obrien, Bernard Enright, Cathal Leahy
The Effect Of Truck Permitting Policy On Us Bridge Loading, Eugene J. Obrien, Bernard Enright, Cathal Leahy
Conference papers
No abstract provided.
Reliability-Based Bridge Assessment Using Enhanced Monte Carlo To Simulate Extreme Traffic Loading, Bernard Enright, Donya Hajializadeh, Eugene J. Obrien
Reliability-Based Bridge Assessment Using Enhanced Monte Carlo To Simulate Extreme Traffic Loading, Bernard Enright, Donya Hajializadeh, Eugene J. Obrien
Conference papers
A framework is presented for the assessment of the safety of a bridge deck under actual traffic loading using an enhanced Monte Carlo method which attempts to reduce computational cost while preserving the advantages of more conventional, computationally intensive, simulation. To generate the bridge loading scenarios, an extensive Weigh-in-Motion (WIM) database is used to calibrate a sophisticated simulation model of two-directional traffic. Traffic and vehicle characteristics are generated from statistical distributions derived from measured traffic data. Two examples are used in this study to assess the usefulness and accuracy of the enhanced method. In the first, a simple example is …
Framework For Formative Assessment Learning Strategies In Built Environment Higher Education Programmes, Lloyd Scott, Christopher Fortune
Framework For Formative Assessment Learning Strategies In Built Environment Higher Education Programmes, Lloyd Scott, Christopher Fortune
Conference papers
Formative assessment has begun to be recognized as a driving force for enhancing student learning. This paper addresses the context of Built Environment (BE) undergraduate programmes and the findings from a research project in the context of the changing Higher Education (HE) environment. The analysis of the literature on formative assessment shows that there is a common concern among the educational researchers about the function and position of assessment in HE today. The overall aim of this research is to contribute to an improvement in the quality of student learning in BE undergraduate education through the development of a theoretical …
The Effect Of Lane Changing On Long-Span Highway Bridge Traffic Loading, Bernard Enright, Colm Carey, Colin C. Caprani
The Effect Of Lane Changing On Long-Span Highway Bridge Traffic Loading, Bernard Enright, Colm Carey, Colin C. Caprani
Conference papers
Maximum loading on long-span bridges typically occurs in congested traffic conditions. As traffic becomes congested car drivers may change lane, increasing the tendency for trucks to travel in platoons. For long-span bridges this phenomenon may increase the regularity and severity of bridge repair programs, with potential significant associated costs. This research investigates the effect of lane changing by car drivers on bridge loading. A Monte Carlo simulation model in which individual car drivers probabilistically decide, based on a lane-changing bias probability, whether or not to change lane has been developed. The sensitivity of bridge loading to this factor is investigated …
Nonlinear Response Of Structures To Characteristic Loading Scenarios, Donya Hajializadeh, Eugene J. Obrien, Bernard Enright, Emma Sheils
Nonlinear Response Of Structures To Characteristic Loading Scenarios, Donya Hajializadeh, Eugene J. Obrien, Bernard Enright, Emma Sheils
Conference papers
To assess the safety of an existing bridge, the traffic loads to which it may be subjected in its lifetime need to be accurately quantified. In this paper the 75 year characteristic maximum traffic load effects are found using a carefully calibrated traffic load simulation model. To generate the bridge loading scenarios, an extensive weigh in motion (WIM) database, from three different European countries, is used. Statistical distributions for vehicle weights, inter-vehicle gaps and other characteristics are derived from the measurements, and are used as the basis for Monte Carlo simulations of traffic representing many years. An advantage of this …
Probabilistic Study Of Lifetime Load Effect Distribution Of Bridges, Donya Hajializadeh, Eugene J. Obrien, Bernard Enright, Colin C. Caprani, Emma Sheils, Simon Wilson
Probabilistic Study Of Lifetime Load Effect Distribution Of Bridges, Donya Hajializadeh, Eugene J. Obrien, Bernard Enright, Colin C. Caprani, Emma Sheils, Simon Wilson
Conference papers
Assessment of highway bridge safety requires a prediction of the probability of occurrence of extreme load effects during the remaining life of the structure. While the assessment of the strength of an existing bridge is relatively well understood, the traffic loading it is subject to, has received less attention in the literature. The recorded traffic data are often limited to a number of days or weeks due to the cost of data collection. Studies in the literature have used many different methods to predict the lifetime maximum bridge load effect using a small amount of data, including fitting block maximum …
Estimation Of Lifetime Maximum Distributions Of Bridge Traffic Load Effects, Eugene J. Obrien, Donya Hajializadeh, Emma Sheils, Bernard Enright
Estimation Of Lifetime Maximum Distributions Of Bridge Traffic Load Effects, Eugene J. Obrien, Donya Hajializadeh, Emma Sheils, Bernard Enright
Conference papers
This paper considers the problem of assessing traffic loading on road bridges. A database of European WIM data is used to determine accurate annual maximum distributions of load effect. These in turn are used to find the probability of failure for a number of load effects. Using the probability of failure as the benchmark, traditional measures of safety – factor of safety and reliability index – are reviewed. Both are found to give inconsistent results, i.e., a given factor of safety or reliability index actually corresponds to a range of different probabilities of failure.
Lane Changing Control To Reduce Traffic Load Effect On Long-Span Bridges, Colin C. Caprani, Bernard Enright, Colm Carey
Lane Changing Control To Reduce Traffic Load Effect On Long-Span Bridges, Colin C. Caprani, Bernard Enright, Colm Carey
Conference papers
Long span bridges are critical parts of a nation’s infrastructure network and congested traffic loading is the governing form of traffic loading. Groups of trucks travelling in conveys are created when fast-er moving vehicles, such as cars, change lane. In this research the authors investigate how the control of these lane-changing events can help reduce the traffic load effects on long span bridges. Real traffic data is used to simulate a traffic stream on a virtual road and bridge using a microsimulation model. Various lane-changing restrictions are examined and compared to the typical case of free lane changing. It is …
Developments In Intelligent Monitoring Of Concrete Structures, T. M. Chrisp, G. Starrs, W. J. Mccarter, E. H. Owens, S. V. Nanukuttan, Niall Holmes, L. Basheer
Developments In Intelligent Monitoring Of Concrete Structures, T. M. Chrisp, G. Starrs, W. J. Mccarter, E. H. Owens, S. V. Nanukuttan, Niall Holmes, L. Basheer
Conference papers
Deterioration in concrete comprises an initiation period and a propagation period. The initiation period is characterised by changes that occur within the concrete in response to the exposure environment and continues until a stage is reached when damage begins to propagate. The propagation period begins at a point in time defined when a particular event occurs (e.g. loss of steel passivity due to chloride ingress) and continues until a specified limit state is reached. The initiation and propagation stages of a deterioration process result from a complex interaction of physical, chemical and electrochemical phenomena. Prediction of the field performance of …
Developments In Monitoring Techniques For Durability Assessment Of Cover-Zone Concrete, W.J. Mccarter, T. M. Chrisp, G. Starrs, Niall Holmes, L. Basheer, M. Basheer, S. V. Nanukuttan
Developments In Monitoring Techniques For Durability Assessment Of Cover-Zone Concrete, W.J. Mccarter, T. M. Chrisp, G. Starrs, Niall Holmes, L. Basheer, M. Basheer, S. V. Nanukuttan
Conference papers
This paper outlines developments in the use of an embedded multi-electrode sensor to study the response of the cover-zone (surface 50mm) to the changing ambient environment. The sensor enables the measurement of the spatial and temporal distribution of the electrical properties of concrete and temperature within the cover-zone thereby allowing an integrated assessment of cover-zone concrete performance. Both laboratory and field results are presented to highlight the information that can be obtained from embedded sensors. When exposed to the natural environment, the temperature dependence of the electrical response is highlighted and standardization protocols are developed to account for this effect. …
Assessing Third Mission Activities, Mike Murphy
Assessing Third Mission Activities, Mike Murphy
Conference papers
No abstract provided.
An Assessment Of The Audio Codec Performance In Voice Over Wlan (Vowlan) Systems, Miroslaw Narbutt, Mark Davis
An Assessment Of The Audio Codec Performance In Voice Over Wlan (Vowlan) Systems, Miroslaw Narbutt, Mark Davis
Conference papers
In this paper we present results of experimental investigation into the performance of three audio codecs (ITU-T G.711, G.723.1 and G.729A) under varying load conditions on a Voice over WLAN system utilizing the IEEE 802.11b wireless LAN standard. The analysis is based upon a new technique for estimating user satisfaction of speech quality calculated from packet delay and packet loss/late measurements. We also demonstrate the importance of the de-jitter buffer playout scheme for insuring speech quality. From our results we conclude that the use of the G.711 audio codec in conjunction with the new adaptive playout scheme gives the highest …