Now showing 1 - 10 of 18
  • Publication
    Weighing-In-Motion of Axles and Vehicles for Europe (WAVE) WP1.2: Bridge WIM Systems
    The objective of the WAVE project was to effect a significant step forward for those responsible  for road networks, through the following actions: Improve the capacity of conventional WIM systems to accurately estimate static loads from measurements of dynamic impact forces applied by axles, through use of arrays of sensors whose combined results can allow for the dynamic interaction between vehicle and pavement. Develop and improve the functioning and accuracy of bridge-based WIM systems through more sophisticated vehicle/bridge interaction modelling and data processing. Develop common data structures, formats and quality assurance procedures to facilitate the exchange and comparison of WIM data throughout Europe, to increase confidence in such  data and to provide reliable management information to decision makers. Perform tests of WIM systems to assess their durability and performance in various climatic conditions, particularly in cold regions where pavements deform and are weaker during the thaw and sensors are susceptible to studded tyres and de-icing salt. Develop standardised calibration methods  and  procedures  by improving  existing methods and extending their applicability to all European climates and types of WIM system. Develop and implement a new WIM technology,  based on an innovative fibre optic sensor  which has considerable potential in terms of quality and the extent of information provided and its insensitivity to harsh climatic conditions.This project constituted a strategic policy initiative to confirm the Europe's leadership in WIM. It led to the development of new technologies such as advanced multiple sensor and bridge WIM systems, a quality assurance procedure to be implemented in a pan-European database, data about the behaviour of WIM systems in harsh environments, an improvement in calibration procedures and  the development of a new European optic-fibre WIM technology. That will help road and transport decision makers.
      667
  • Publication
    Characteristic dynamic traffic load effects in bridges
    When formulating an approach to assess bridge traffic loading with allowance for Vehicle-Bridge Interaction (VBI), a trade-off is necessary between the limited accuracy and computational demands of numerical models and the limited time periods for which experimental data is available. Numerical modelling can simulate sufficient numbers of loading scenarios to determine characteristic total load effects, including an allowance for VBI. However, simulating VBI for years of traffic is computationally expensive, often excessively so. Furthermore, there are a great many uncertainties associated with numerical models such as the road surface profile and the model parameter values (e.g., spring stiffnesses) for the heavy vehicle fleet. On site measurement of total load effect, including the influence of VBI, overcomes many of these uncertainties as measurements are the result of actual loading scenarios as they occur on the bridge. However, it is often impractical to monitor bridges for extended periods of time which raises questions about the accuracy of calculated characteristic load effects. Soft Load Testing, as opposed to Proof Load or Diagnostic Load Testing, is the direct measurement of load effects on bridges subject to random traffic. This paper considers the influence of measurement periods on the accuracy of soft load testing predictions of characteristic load effects, including VBI, for bridges with two lanes of opposing traffic. It concludes that, even for relatively short time periods, the estimates are reasonably accurate and tend to be conservative. Provided the data is representative, Soft Load Testing is shown to be a useful tool for calculating characteristic total load effect.
    Scopus© Citations 56  1307
  • Publication
    Direct measurement of dynamics in road bridges using a bridge weigh-in-motion system
    (Technika. Vilnius Gediminas Technical University, 2013-12) ; ; ;
    A method is presented of measuring a bridge’s characteristic allowance for dynamic interaction in the form of Assessment Dynamic Ratio. Using a Bridge Weigh-in-Motion system, measurements were taken at a bridge in Slovenia over 58 days. From the total observed traffic population, 5-axle trucks were extracted and studied. The Bridge Weigh-in-Motion system inferred the static weights of the trucks, giving each measured event’s dynamic increment of load. Theoretical simulations were carried out using a 3-dimensional vehicle model coupled with a bridge plate model, simulating a traffic population similar to the population measured at the site. These theoretical simulations varied those properties of the 5-axle fleet that influence the dynamic response; simulating multiple sets of total (dynamic + static) responses for a single measured static strain response. Extrapolating the results of these theoretical simulations to a 50-year Assessment Dynamic Ratio gives similar results to those obtained by extrapolating the data measured using the Bridge Weigh-in-Motion system. A study of the effect of Bridge Weigh-in-Motion system errors on the predictions of Assessment Dynamic Ratio is conducted, identifying a trend in the Bridge Weigh-in-Motion calculations of maximum static response. The result of this bias is in turn quantified in the context of predicting characteristic maximum total load effect.
    Scopus© Citations 10  449
  • Publication
    A Review of Road Structure Data in Six European Countries
    The European Union has expanded significantly in recent years. Sustainable trade within the Union leading to economic growth to the benefit of the 'old' and 'new' member states is thus extremely important. The road infrastructure is strategic and vital to such development since an uneven transport infrastructure, in terms of capacity and condition, has the potential to reinforce uneven development trends and hinder economic convergence of old and new member states. Significantly, in the decades since their design and construction, loading conditions have significantly changed for many major highway infrastructure elements/networks due primarily to increased freight volumes and vehicle sizes. This coupled with the gradual deterioration of a significant number of highway structures, due to their age, and the absence of a pan-European assessment framework can be expected to affect the smooth functioning of the infrastructure in its as-built condition, through increased periods of reduced flow due to planned and unplanned interventions for repair/rehabilitation. This paper reports the findings of a survey regarding the current status of the highway infrastructure elements in six countries within the European Union as reported by the owners/operators. The countries surveyed include a cross section of ‘existing’ older countries and ‘new’ accession countries. The current situations for bridges, culverts, tunnels and retaining walls are reported along with their potential replacement costs. The findings act as a departure point for further studies in support of a Centralized and/or Synchronised EU approach to Infrastructure Maintenance Management. Information in the form presented in this paper is central to any future decision making frameworks in terms of trade route choice and operations, monetary investment, optimized maintenance, management and rehabilitation of the built infrastructure and the economic integration of the newly joined member states.
      754
  • Publication
    Comparison of Two Independently Developed Bridge Weigh-In-Motion Systems
    (Inderscience Enterprises, 1999) ; ;
    This paper describes an experiment in which 2 independently developed bridge weigh-in-motion (WIM) systems are tested and compared, both for accuracy and durability. The systems, an Irish prototype still under development and a commercially available American system, were tested on a bridge in Slovenia. 11 statically pre-weighted trucks were each driven over the bridge several times at a range of typical highway speeds. Accuracies for axle and gross vehicle weights are presented within the framework of the draft European WIM specification, and the bias which can be introduced by the selection of a calibration truck is demonstrated. Performance factors relating to durability are also discussed with particular emphasis on axle detectors
      1030
  • Publication
    Using statistical analysis of an acceleration-based bridge weigh-in-motion system for damage detection
    This paper develops a novel method of bridge damage detection using statistical analysis of data from an acceleration-based bridge weigh-in-motion (BWIM) system. Bridge dynamic analysis using a vehicle-bridge interaction model is carried out to obtain bridge accelerations, and the BWIM concept is applied to infer the vehicle axle weights. A large volume of traffic data tends to remain consistent (e.g., most frequent gross vehicle weight (GVW) of 3-axle trucks); therefore, the statistical properties of inferred vehicle weights are used to develop a bridge damage detection technique. Global change of bridge stiffness due to a change in the elastic modulus of concrete is used as a proxy of bridge damage. This approach has the advantage of overcoming the variability in acceleration signals due to the wide variety of source excitations/vehicles-data from a large number of different vehicles can be easily combined in the form of inferred vehicle weight. One year of experimental data from a short-span reinforced concrete bridge in Slovenia is used to assess the effectiveness of the new approach. Although the acceleration-based BWIM system is inaccurate for finding vehicle axle-weights, it is found to be effective in detecting damage using statistical analysis. It is shown through simulation as well as by experimental analysis that a significant change in the statistical properties of the inferred BWIM data results from changes in the bridge condition.
      50Scopus© Citations 21
  • Publication
    EU FP6 - ARCHES Deliverable D10: Recommendations on dynamic amplification allowance
    The ARCHES (Assessment and Rehabilitation of Central European Highway Structures) project (2006-09) involved partners from Belgium, Croatia, Czech Republic, Ireland, Italy, Poland, Slovenia, Spain, Switzerland and The Netherlands. The overall goal of the project is to reduce any gaps in the standard of highway infrastructure between Central and Eastern European Countries, particularly New Member States and the rest of the EU. Deliverable D10 is within WP2: optimise the use of existing infrastructure through better safety assessment and monitoring procedures which will avoid interventions, i.e., avoid unnecessary replacing or improving structures that are in fact perfectly safe. In particular, D10 provides a more realistic site-specific dynamic allowance for traffic loading than those genral values recommended in bridge codes.Correct evaluation of the behaviour of highway bridges under heavy traffic loading is extremely important both for the enhancement of design techniques, and also for the assessment of existing infrastructure. It is widely accepted that shortfalls exist in the determination of the traffic load which the bridge may be required to support during its expected lifetime due to inadequate consideration of amongst other factors, the dynamic interaction between the bridge structure and the heavy vehicles crossing it. Since it is the overall objective of this deliverable to combine lifetime static load effect values, with realistic dynamic amplification factors (to obtain an overall total lifetime load effect) there are two distinct parts:1) The calculation of bridge static load effect due to site-specific traffic flow, which is discussed in subtask 2.1.1 (Deliverable D08) along with the resultant assessment of bridge lifetime static load effect, and the selection of those loading events that are deemed critical (statically).Examples on how to determine these bridge traffic load models using Weigh-In-Motion (WIM) data and their configuration when using data from Central European countries are provided in subtask 2.1.1 on bridge traffic load monitoring. This subtask has also compared results between data from Western and Central European countries.2) Deliverable D10 focuses on the assessment of the levels of dynamic interaction occurring between a bridge and its associated vehicular traffic. This analysis incorporates a review of those recommendations given in current design/assessment codes for dynamic allowance.Then, the procedure to obtain a site-specific dynamic amplification factor using theoretical simulations and available experimental data is described. Some specific issues concerning the dynamic allowance associated to: (a) deteriorated bridges; (b) pre-existing bridge vibrations; (c) maximum total effects developing in sections different from midspan, (d) the existence of a bump prior to the bridge, or (e) critical loading cases such as cranes, are also discussed. Finally,general recommendations on dynamic allowance are provided.
      152
  • Publication
    Recommendations on dynamic amplification allowance
    (European Commission, 2009-08) ;
    The ARCHES (Assessment and Rehabilitation of Central European Highway Structures) project (2006-09) involved partners from Belgium, Croatia, Czech Republic, Ireland, Italy, Poland, Slovenia, Spain, Switzerland and The Netherlands. The overall goal of the project is to reduce any gaps in the standard of highway infrastructure between Central and Eastern European Countries, particularly New Member States and the rest of the EU. Deliverable D10 is within WP2: optimise the use of existing infrastructure through better safety assessment and monitoring procedures which will avoid interventions, i.e., avoid unnecessary replacing or improving structures that are in fact perfectly safe. In particular, D10 provides a more realistic site-specific dynamic allowance for traffic loading than those genral values recommended in bridge codes.Correct evaluation of the behaviour of highway bridges under heavy traffic loading is extremely important both for the enhancement of design techniques, and also for the assessment of existing infrastructure. It is widely accepted that shortfalls exist in the determination of the traffic load which the bridge may be required to support during its expected lifetime due to inadequate consideration of amongst other factors, the dynamic interaction between the bridge structure and the heavy vehicles crossing it. Since it is the overall objective of this deliverable to combine lifetime static load effect values, with realistic dynamic amplification factors (to obtain an overall total lifetime load effect) there are two distinct parts:1) The calculation of bridge static load effect due to site-specific traffic flow, which is discussed in subtask 2.1.1 (Deliverable D08) along with the resultant assessment of bridge lifetime static load effect, and the selection of those loading events that are deemed critical (statically).Examples on how to determine these bridge traffic load models using Weigh-In-Motion (WIM) data and their configuration when using data from Central European countries are provided in subtask 2.1.1 on bridge traffic load monitoring. This subtask has also compared results between data from Western and Central European countries.2) Deliverable D10 focuses on the assessment of the levels of dynamic interaction occurring between a bridge and its associated vehicular traffic. This analysis incorporates a review of those recommendations given in current design/assessment codes for dynamic allowance.Then, the procedure to obtain a site-specific dynamic amplification factor using theoretical simulations and available experimental data is described. Some specific issues concerning the dynamic allowance associated to: (a) deteriorated bridges; (b) pre-existing bridge vibrations; (c) maximum total effects developing in sections different from midspan, (d) the existence of a bump prior to the bridge, or (e) critical loading cases such as cranes, are also discussed. Finally,general recommendations on dynamic allowance are provided.
      343
  • Publication
    EU FP6 - ARCHES Deliverable D08: Recommendations on the use of results of monitoring on bridge safety assessment and maintenance
    The ARCHES, which is the Specific Targeted Research Project, was planned in response to the European Commission’s call for proposals 3B, addressing Topic 2.6 ‘Design and manufacture of new construction concepts’ of objective ‘Sustainable Surface Transport’ under the Thematic priority 1.6 ‘Sustainable Development, Global Change and Ecosystems’ of the GROWTH part of the Sixth Framework Programme. The contract was signed by the Commission on the 25th of October 2006. Project commencement date was the 1st of September 2006 and the duration of the project is 36 months.
      179
  • Publication
    Critical speed for the dynamics of truck events on bridges with a smooth road surface
    Simple numerical models of point loads are used to represent single and multiple vehicle events on two-lane bridges with a good road profile. While such models are insufficiently complex to calculate dynamic amplification accurately, they are presented here to provide an understanding of the influence of speed and distance between vehicles on the bridge dynamic response. Critical combinations of speed as a function of main bridge natural frequency and meeting point of two vehicles travelling in opposite directions are identified. It is proposed that such simple models can be used to estimate the pattern of critical speeds versus dynamic amplification for heavy trucks on a bridge with a relatively smooth surface. The crossing of a three-dimensional spring-dashpot truck is simulated over a bridge plate model to test this hypothesis for a range of road roughness. Further validation is carried out using the site-specific mean pattern associated to field measurements due to the passage of a truck population. The latter is found to be closely resembled by the theoretical pattern derived from simple point load models.
    Scopus© Citations 22  1567