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Estimating Characteristic Bridge Loads On A Non-Primary Road Network, Eugene J. Obrien, Bernard Enright, Brendan Williams, Cathal Leahy Jan 2012

Estimating Characteristic Bridge Loads On A Non-Primary Road Network, Eugene J. Obrien, Bernard Enright, Brendan Williams, Cathal Leahy

Conference papers

When collecting truck loading data on a primary road network a common approach is to install a large network of permanent pavement-based Weigh-In-Motion systems. An alternative to this approach would be to use one or more portable Bridge Weigh-In-Motion systems which could be moved between bridges at regular intervals to determine the traffic loading throughout the network. A data collection strategy is needed to put such a system to best use. This paper details the data collection strategies which were examined for the National Roads Authority in Ireland. The use of urban economic concepts including Central Place Theory are discussed …


Portable Bridge Wim Data Collection Strategy For Secondary Roads, Bernard Enright, Cathal Leahy, Eugene J. Obrien, Jennifer Keenahan Jan 2012

Portable Bridge Wim Data Collection Strategy For Secondary Roads, Bernard Enright, Cathal Leahy, Eugene J. Obrien, Jennifer Keenahan

Conference papers

A common method of collecting traffic loading data across a large road network is to use a network of permanent pavement-based WIM systems. An alternative is to use one or more portable Bridge Weigh-In-Motion systems which are moved periodically between bridges on the network. To make optimum use of such a system, a suitable data collection strategy is needed to choose locations for the system. This paper describes a number of possible strategies which the authors have investigated for the National Roads Authority in Ireland. The different strategies are examined and their advantages and disadvantages compared. Their effectiveness at detecting …


Modeling Extreme Traffic Loading On Bridges Using Kernel Density Estimators, Cathal Leahy, Eugene J. Obrien, Bernard Enright Jan 2011

Modeling Extreme Traffic Loading On Bridges Using Kernel Density Estimators, Cathal Leahy, Eugene J. Obrien, Bernard Enright

Conference papers

Kernel density estimators are a non-parametric method of estimating the probability density function of sample data. In this paper, the method is applied to find characteristic maximum daily truck weights on highway bridges. The results are then compared with the conventional approach


A New Congested Traffic Load Model For Highway Bridges, Colin C. Caprani, Colm Carey, Bernard Enright Jan 2010

A New Congested Traffic Load Model For Highway Bridges, Colin C. Caprani, Colm Carey, Bernard Enright

Conference papers

Long span highway bridges are critical components of any nation’s infrastructure. Therefore accurate assessment of highway bridge loading is essential, and it is well known that congested traffic governs load effect for such bridges. Current congestion models use conservative assumptions about traffic and inter-vehicle gaps. This research investigates congested traffic flow through the use of traffic microsimulation which has the ability to reproduce complex traffic phenomena based on driver interactions. A time series model has been developed to produce a speed time-series similar to the results of the microsimulation. The speed time-series from the new model, combined with the established …


Highway Bridge Assessment For Dynamic Interaction With Critical Vehicles, Daniel Cantero, Eugene J. Obrien, Arturo González, Bernard Enright, Cillian Rowley Jan 2009

Highway Bridge Assessment For Dynamic Interaction With Critical Vehicles, Daniel Cantero, Eugene J. Obrien, Arturo González, Bernard Enright, Cillian Rowley

Conference papers

Dynamic vehicle-bridge interaction is often considered for the most common classes of vehicle such as the 5-axle articulated truck. However, the dynamic response of bridges to this type of trucks is quite different to the response to the vehicles more likely to feature in maximum-in-lifetime traffic loading events. This paper focuses on large (>100 tonne) cranes and crane-type vehicles that have been recorded at Weigh-in-Motion sites in Europe. This paper analyses the total bending moment due to these vehicles on short to medium span bridges and compare them to 5- axle articulated trucks. To account for the variability in …


The Structural Reliability Of Bridges Subject To Time-Dependent Deterioration, Colin C. Caprani, C. Mcnally, E. J. O'Brien, A. Bordallo-Ruiz Jan 2007

The Structural Reliability Of Bridges Subject To Time-Dependent Deterioration, Colin C. Caprani, C. Mcnally, E. J. O'Brien, A. Bordallo-Ruiz

Conference papers

The reliability of the structural performance of any given structure is affected by both in-service loading and material deterioration due to environmental attack. They must be evaluated at any given time in order to compute lifetime probability of failure. This paper presents an innovative methodology to derive the structure lifetime load effect due to existing traffic using a statistical tool known as Predictive Likelihood. Loss of resistance due to corrosion originated by chloride ingression is also taken into account. Finally the lifetime probability of failure is evaluated via the application of a time-discretization strategy.


Finding The Distribution Of Bridge Lifetime Load Effect By Predictive Likelihood, Colin C. Caprani, E. J. O'Brien Jul 2006

Finding The Distribution Of Bridge Lifetime Load Effect By Predictive Likelihood, Colin C. Caprani, E. J. O'Brien

Conference papers

To assess the safety of an existing bridge, the loads to which it may be subject in its lifetime are required. Statistical analysis is used to extrapolate a sample of load effect values from the simulation period to the required design period. Complex statistical methods are often used and the end result is usually a single value of characteristic load effect. Such a deterministic result is at odds with the underlying stochastic nature of the problem. In this paper, predictive likelihood is shown to be a method by which the distribution of the lifetime extreme load effect may be determined. …


Statistical Computation For Extreme Bridge Traffic Load Effects, Colin C. Caprani, E. J. O'Brien Jan 2006

Statistical Computation For Extreme Bridge Traffic Load Effects, Colin C. Caprani, E. J. O'Brien

Conference papers

The maintenance of highway infrastructure constitutes a major expenditure in many countries. This cost can be reduced significantly by minimizing the repair or replacement of highway bridges. In the assessment of existing bridges, the strength estimate tends to be more accurate than that of traffic loading, due to the more variable nature of loading. Recent advances in the statistical analysis of highway bridge traffic loading have resulted in more accurate forecasts of the actual loading to which a bridge is subject. While these advances require extensive numerical computation, they can significantly improve the accuracy of the calculation. This paper outlines …


Site-Specific Probabilistic Load Modelling For Bridge Reliability Analysis, Colin C. Caprani, A. Belay, A. J. O'Connor Jan 2003

Site-Specific Probabilistic Load Modelling For Bridge Reliability Analysis, Colin C. Caprani, A. Belay, A. J. O'Connor

Conference papers

Reliability assessment of a short span beam-slab reinforced concrete bridge in Vienna is proposed using site-specific traffic data recorded using the Slovenian Weigh in Motion (SiWIM) system. An initial evaluation of the bridge using a determinintic approach shows that the critical limit state is bending. This paper describes the statistical analysis of the SiWIM data and the traffic flow simulations performed to predict the characteristic extreme load effects to which the bridge may be subjected during its remaining lifetime. These values are compared to the magnitude obtained from a deterministic approach. The influence lines used in the simulations are the …