Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Engineering

Developments In Performance Monitoring Of Concrete Exposed To Extreme Environments., W. J. Mccarter, T. M. Chrisp, G. Starrs, A. Adamson, E. Owens, P. A. M. Basheer, S. V. Nanukuttan, S. Srinivasan, Niall Holmes Dec 2011

Developments In Performance Monitoring Of Concrete Exposed To Extreme Environments., W. J. Mccarter, T. M. Chrisp, G. Starrs, A. Adamson, E. Owens, P. A. M. Basheer, S. V. Nanukuttan, S. Srinivasan, Niall Holmes

Articles

The performance of the surface zone of concrete is acknowledged as a major factor governing the rate of deterioration of reinforced concrete structures because it provides the only barrier to the ingress of water containing dissolved ionic species such as chlorides, which ultimately initiate corrosion of the reinforcement. In situ monitoring of cover-zone concrete is therefore critical in attempting to make realistic predictions as to the in-service performance of the structure. To this end, this paper presents developments in a remote interrogation system to allow for continuous, real-time monitoring of the cover-zone concrete from an office setting. Use is made …


A Parametric Study Of Pedestrian Vertical Force Models For Dynamic Analysis Of Footbridges, Paul Archbold, Joe Keogh, Colin C. Caprani, Paul Fanning Jan 2011

A Parametric Study Of Pedestrian Vertical Force Models For Dynamic Analysis Of Footbridges, Paul Archbold, Joe Keogh, Colin C. Caprani, Paul Fanning

Conference papers

Footbridge vibration has received much attention in recent years. However, stochastic models for crowd loading are not common, and estimation of crowd-induced vibration is typically done through enhancement factors applied to single pedestrian loading models. This work compares two such models, a moving force model and a spring-mass-damper model (SMD). Typical ranges for various pedestrian parameters are examined, and it is found that the pacing frequency has by far the greatest influence on bridge vibration response. It is also found that the magnitude of the response for pacing frequencies near the bridge natural frequency is lower for the SMD model, …


Characteristic Vertical Response Of A Footbridge Due To Crowd Loading, Colin C, Caprani, Joe Keogh, Paul Archbold, Paul Fanning Jan 2011

Characteristic Vertical Response Of A Footbridge Due To Crowd Loading, Colin C, Caprani, Joe Keogh, Paul Archbold, Paul Fanning

Conference papers

The characteristic vertical vibration of a flexible footbridge subject to 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 single pedestrian model, represented by a spring mass damper, which incorporates variables such as pedestrian mass and body stiffness, is used to calibrate a computationally efficient moving force model. This calibrated moving force model is further used in Monte Carlo simulations of non-homogenous crowds to estimate characteristic vertical vibration levels. Enhancement factors, which could …


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


Modelling Of Highway Bridge Traffic Loading: Some Recent Advances, Bernard Enright, Colin C. Caprani, Eugene J. Obrien Jan 2011

Modelling Of Highway Bridge Traffic Loading: Some Recent Advances, Bernard Enright, Colin C. Caprani, Eugene J. Obrien

Conference papers

The accurate estimation of site-specific lifetime extreme traffic load effects is an important element in the cost-effective assessment of bridges. In recent years, the improved quality and increasing use of weigh-in-motion technology has meant that better quality and larger databases of vehicle weights are now available. This has enabled measurements of the regular occurrence of extremely heavy vehicles, with weights in excess of 100 t. The collected measurements have been used as the basis for building and calibrating a Monte Carlo simulation model for bridge loading. The computer programs written to implement this model generate simulated traffic in two lanes …


Modeling Same-Direction Two-Lane Traffic For Bridge Loading, Eugene J. Obrien, Bernard Enright Jan 2011

Modeling Same-Direction Two-Lane Traffic For Bridge Loading, Eugene J. Obrien, Bernard Enright

Articles

Many highway bridges carry traffic in two same-direction lanes, and modeling the traffic loading on such bridges has been the subject of numerous studies. Different assumptions have been used to model multiple-presence loading events, particularly those featuring one truck in each lane. Using a database of weigh-in-motion measurements collected at two European sites for over 1 million trucks, this paper examines the relationships between adjacent vehicles in both lanes in terms of vehicle weights, speeds and inter-vehicle gaps. It is shown that there are various patterns of correlation, some of which are significant for bridge loading. A novel approach to …