Training in European Asset Management

Researcher - Xiaoyi Zhou 

Institute:

Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Nantes, France

Supervisor(s):

Franziska Schmidt and Florence Merlevède

Project Description:

Evolution and statistics of the effects of truck loads on engineering structures

WIM systems record data of traffic over months and provides us with vehicle type, axle load, GVW, axle spacing, length, distance between the following vehicles, etc. This data may be extrapolated in order to apply the extreme value theory. But abnormal vehicles, like cranes, low ladders or other exceptional transport vehicles  threatened this extrapolation. We will try to investigate how to overcome this and obtain statistical points.

Moreover, if combining this WIM data with influence lines, we obtain the static effects on the structure. But these effects can also be measured directly on the bridges. We will try to obtain such measurements and apply the same techniques of extrapolation to them.

Researcher - Alessandro Lipari

Institute:

University College Dublin, Ireland

Supervisor(s):

Eugene O'Brien and Colin Caprani

Project Description:

Micro-simulation of live loads on long-span bridges

The research aims at developing a comprehensive methodology for estimating the traffic loadings and their effect on long-span bridges, since traditional design methods are usually rather conservative. A micro-simulation program (i.e. simulating the traffic as made up of individual vehicles) is being extensively tested and will be calibrated with real traffic data collected using both WIM ('weigh-in-motion') sensors embedded in the road and cameras. The data will be then analysed statistically to find the maximum load effect expected over 1000 years on some sample long-span bridges.

Researcher - Mark Treacy

Institute:

Laboratory of Maintenance and Safety of Structures (MCS), Ecole Polytechnique Fédérale de Lausanne (EPFL)

Supervisor(s):

Prof. Eugen Brühwiler

Project Description:

Verification of structural and fatigue safety of reinforced concrete road bridges using monitored data

This project will establish a methodology for the overall evaluation of structural and fatigue safety of RC road bridges using monitored data and reliability theory. Long term WIM monitoring will be used to estimate the fatigue stress cycles experienced in bridges from today’s road traffic. In addition, the latest sensing system technologies will be exploited to accurately determine the real stress cycles in the reinforcement of road bridges by means of   strategically placed sensors at fatigue problematic ‘hot spots’. The project will also involve collaboration with Ramboll Consulting Engineers, utilizing their expertise on applying reliability theory to infrastructure management.

Researcher - Niklas Bagge

Institute:

Rambøll (Denmark) and Trinity Collage Dublin

Supervisor(s):

Claus Pedersen (Rambøll) and Alan O'Connor (Trinity Collage Dublin)

Project Description:

Reliability-based analysis of existing concrete structures focusing on modelling of uncertainties and plastic redistribution of sectional forces

This research project will focus on minimisation of whole life cost of existing structures with maximisation of performance. The objective of maximisation of performance of existing structures will be achieved by reliability based analysis, including modeling of uncertainties and plastic redistribution of sectional forces. This will be applied to concrete structures with reinforcement and pre-stressed concrete structures, respectively. Some points to take into account with regard to these two types of structure are for example the reinforcement ratio, rotation capacity, bond between steel and concrete and non-linear material properties. Based on these points the aim is to determine allowable redistribution of sectional forces and specify the "suitable" requirement for the safety index, β, of structures dependent on the failure mode (brittle or ductile) and the analysis methods used (elastic, plastic, degree of conservatism etc.).

Researcher – Donya Hajializadeh

Institute:

University College Dublin, Ireland

Supervisor(s):

Prof. Eugene O'Brien

Project Description:

Advancement of a combined structural health monitoring/weigh in motion systems

Prediction of the present and future state of Reinforced Concrete (RC) bridges is important if proper planning for inspection and maintenance is to be made. Practical evidence and theoretical analysis suggests that many structures can tolerate considerable damage without serious reduction to their load carrying capacity. Therefore visual impression-based maintenance is not an optimum solution particularly when financial resources are limited. To support this notation, accurate models are needed to predict the deterioration rate of the structural load carrying capacity over time.

Information about present and anticipated bridge reliabilities can be used in conjunction with decision models to provide a rational decision-making tool for the assessment of bridges and other structural systems. Moreover, 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 project presents an innovative methodology to derive the structure lifetime load effect due to existing traffic and takes into consideration the spatial variability of the deterioration parameters, thereby demonstrating the importance of its inclusion in any such analysis. The goal is to provide management decisions that will balance lifetime system reliability and expected lifecycle cost in an optimal manner.