Papers by Bernard Enright
Engineering Structures, 2007
ABSTRACT
Characteristic dynamic increment for extreme traffic loading events on short and medium span high... more Characteristic dynamic increment for extreme traffic loading events on short and medium span highway bridges
Bridge Maintenance, Safety and Management (IABMAS\u2710) the Fifth International IABMAS Conferenc... more Bridge Maintenance, Safety and Management (IABMAS\u2710) the Fifth International IABMAS Conference, Philadelphia, USA, 11-15 July 2010Accurate traffic loading models based on measured data are essential for the accurate assessment of existing bridges. There are well-established methods for the Monte Carlo simulation of single lanes of traffic, and this can easily be extended to model the loading on bridges with two independent streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic. This paper analyses traffic patterns using multi-lane WIM data collected at two European sites. It describes an approach to the Monte Carlo simulation of this traffic which applies variable bandwidth kernel density estimators to empirical traffic patterns of vehicle weights, gaps and speeds. This method provides a good match with measured data for multi-truck bridge loading events, and it is shown that correlation has a small but significant effect on lifetime maximum load effects.Deposited by bulk impor
This paper reviews a range of statistical approaches to illustrate the influence of data quality ... more This paper reviews a range of statistical approaches to illustrate the influence of data quality and quantity on the probabilistic modelling of traffic load effects. It also aims to demonstrate the importance of long-run simulations in calculating characteristic traffic load effects. The popular methods of Peaks Over Threshold and Generalized Extreme Value are considered but also other methods including the Box-Cox approach, fitting to a Normal distribution and the Rice formula. For these five methods, curves are fitted to the tails of the daily maximum data. Bayesian Updating and Predictive Likelihood are also assessed, which require the entire data for fittings. The accuracy of each method in calculating 75-year characteristic values and probability of
Bridge Maintenance, Safety, Management, Resilience and Sustainability, 2012
Maximum loading on long-span bridges typically occurs in congested traffic conditions. As traffic... more 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 for different bridge lengths and traffic compositions. This research concludes that the lane-changing behavior of car drivers has an effect on bridge loading for long-span bridges, and the magnitude of this effect is quite sensitive to the percentage of trucks in the traffic.
Polymer Journal, 2009
10th International Conference on Safety, Reliability and Risk of Structures (ICOSSAR 2009), Osaka... more 10th International Conference on Safety, Reliability and Risk of Structures (ICOSSAR 2009), Osaka, Japan, 13-17 September, 2009
This paper addresses the use of portable Bridge Weigh-in-Motion (B-WIM) systems as an alternative... more This paper addresses the use of portable Bridge Weigh-in-Motion (B-WIM) systems as an alternative method of collecting traffic loading data. The authors describe data collection strategies for selecting B-WIM systems locations investigated for the National Roads Authority in Ireland. They discuss advantages and disadvantages of various strategies as well as their effectiveness in detecting a heavy loading event.
Engineering Structures, 2010
More accurate assessment of safety can prevent unnecessary repair or replacement of existing brid... more More accurate assessment of safety can prevent unnecessary repair or replacement of existing bridges which in turn can result in great cost savings at network level. The allowance for dynamics is a significant component of traffic loading in many bridges and is often unnecessarily conservative. Critical traffic loading scenarios are considered in this paper with a model that allows for vehicle-bridge interaction and takes into account the road surface condition. Characteristic dynamic allowance values are presented for the assessment of midspan bending moment in a wide range of short to medium span bridges for bi-directional traffic.
This paper presents results based on the analysis of an extensive database of weigh-in-motion (WI... more This paper presents results based on the analysis of an extensive database of weigh-in-motion (WIM) data collected at five European highway sites in recent years. The data are used as the basis for a Monte Carlo simulation of two lane traffic, both bidirectional and ...
Provided by the author(s) and University College Dublin Library in accordance with publisher poli... more Provided by the author(s) and University College Dublin Library in accordance with publisher policies. Please cite the published version when available. Downloaded 2016-05-10T16:16:59Z Some rights reserved. For more information, please see the item record link above.
European Road freight transport has increased by 38 % between 1995 and 2005 and this strong growt... more European Road freight transport has increased by 38 % between 1995 and 2005 and this strong growth trajectory seems likely to continue into the future. To address this growth without compromising the competitiveness of European transport, some countries are contemplating the introduction of longer and heavier trucks, with up to 8 axles and gross weights of up to 60 t. This has the advantage of reducing the number of vehicles for a given volume or mass of freight, reducing labour, fuel and other costs. However, many roads authorities are concerned about the implications for Europe’s bridge infrastructure. For bridge loading, it is the combination of gross weight and truck length that determine load effects such as bending moment and shear force in the deck. A probabilistic analysis is required to assess whether these proposed trucks will lead to greater maximum lifetime (characteristic) load effects. If this was found to be the case, it would necessitate the strengthening of a great ...
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Bridge structures are key components of highway infrastructure and their safety is clearly of gre... more Bridge structures are key components of highway infrastructure and their safety is clearly of great importance. Safety assessment of highway bridges requires accurate prediction of the extreme load effects, taking account of spatial variability through the bridge width and length. This concept of spatial variability i s also known as random field analysis. Reliability - based bridge assessment permits the inclusion of uncertainty in all parameters and models associated with the deterioration process. Random field analysis takes account of the probability that two points n ear each other on a bridge will have correlated properties. This method incorporates spatial variability which results in a more accurate reliability assessm ent. This paper presents an integrated model for spatial reliability analysis of reinforced concre te bridges that considers both the bridge capacity and traffic load. A sophisticated simulation model of two - directional traffic is used to determine accurate ...
This paper investigates the use of Bayesian updating to improve estimates of characteristic bridg... more This paper investigates the use of Bayesian updating to improve estimates of characteristic bridge traffic loading. Over recent years the use Weigh-In-Motion technologies has increased hugely. Large Weigh-In-Motion databases are now available for multiple sites on many road networks. The objective of this work is to use data gathered throughout a road network to improve site-specific estimates of bridge loading at a specific Weigh-In-Motion site on the network. Bayesian updating is a mathematical framework for combining prior knowledge with new sample data. The approach is applied here to bridge loading using a database of 81.6 million truck records, gathered at 19 sites in the US. The database represents the prior knowledge of loading throughout the road network and a new site on the network is simulated. The Bayesian approach is compared with a non-Bayesian approach, which uses only the site-specific data, and the results compared. It is found that the Bayesian approach significan...
Title EU FP6 ARCHES Deliverable D08: Recommendations on the use of results of monitoring on bridg... more Title EU FP6 ARCHES Deliverable D08: Recommendations on the use of results of monitoring on bridge safety assessment and maintenance Authors(s) Ralbovsky, Marian; Cremona, Cristian; Enright, Bernard; OBrien, Eugene J; González, Arturo; et al. Publication date 2009-08-31 Publisher 6th EU FP Link to online version http://arches.fehrl.org/?m=7&mode=download&id_file=9674 Item record/more information http://hdl.handle.net/10197/10134
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Papers by Bernard Enright