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Full-Text Articles in Structural Engineering

Reliability Analysis Of Footbridge Serviceability Considering Crowd Loading, Joe Keogh, Colin C. Caprani, Paul Archbold, Paul Fanning Jan 2012

Reliability Analysis Of Footbridge Serviceability Considering Crowd Loading, Joe Keogh, Colin C. Caprani, Paul Archbold, Paul Fanning

Conference papers

The characteristic vertical response of flexible footbridges subjected to single pedestrian and crowd loading is examined in this paper. Typically, bridge vibrations produced from a crowd of pedestrians are estimated by using an enhancement factor applied to the effect caused by a single pedestrian. In this paper a moving force model is used in Monte Carlo simulations of a non-homogeneous sample of single pedestrians and crowds to estimate characteristic vertical vibration levels. Also in this work, statistical distributions of the bridge parameters are considered, these include flexural rigidity, mass and rotational stiffness at the supports. It was previously proven by …


The Effect Of Clusters Within Crowds Of Pedestrians On The Vertical Response Of A Flexible Footbridge, Joe Keogh, Colin C. Caprani, Paul Archbold, Paul Fanning Jan 2012

The Effect Of Clusters Within Crowds Of Pedestrians On The Vertical Response Of A Flexible Footbridge, Joe Keogh, Colin C. Caprani, Paul Archbold, Paul Fanning

Conference papers

The issue of excessive vibrations of footbridges due to the passage of pedestrians has been well documented in the past decade. Despite this there still remains great uncertainty as to how to predict the acceleration response of a footbridge due to crowd loading. This paper investigates the vibration response of a flexible footbridge subjected to crowd loading. Using a statistical model which caters for the variability of pedestrians, the vibration response of the footbridge is obtained. In this work, the effect of social groups or clusters of pedestrians in a crowd is investigated. Herein a cluster is defined as two …


The Response Of A Footbridge To Pedestrians Carrying Additional Mass, Darragh O'Sullivan, Colin Caprani, Joe Keogh Jan 2012

The Response Of A Footbridge To Pedestrians Carrying Additional Mass, Darragh O'Sullivan, Colin Caprani, Joe Keogh

Conference papers

Footbridges with low natural frequency are susceptible to excessive vibration serviceability problems if the pedestrian pacing frequency matches the bridge natural frequency. Much research has been done into describing the response of a footbridge to single pedestrian loading. However, many pedestrians carry additional mass such as shopping bags and backpacks, and this has generally not been accounted for in previous research. This work examines this problem using an experimental bridge excited with many single pedestrian events, both with and without additional mass. The vertical acceleration response is measured and compared to moving force, moving mass, and moving spring-mass-damper models. The …


Vertical Response Of A Footbridge Subjected To Stocastic Crowd Loading, Joe Keogh Jan 2012

Vertical Response Of A Footbridge Subjected To Stocastic Crowd Loading, Joe Keogh

Conference papers

No abstract provided.


The Effect Of Lane Changing On Long-Span Highway Bridge Traffic Loading, Bernard Enright, Colm Carey, Colin C. Caprani Jan 2012

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 …


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 …


Nonlinear Response Of Structures To Characteristic Loading Scenarios, Donya Hajializadeh, Eugene J. Obrien, Bernard Enright, Emma Sheils Jan 2012

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 Jan 2012

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 Jan 2012

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 Jan 2012

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 …


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 …