scholarly journals Evaluation of traffic load models for fatigue verification of European road bridges

2020 ◽  
Vol 225 ◽  
pp. 111326
Author(s):  
Johan Maljaars
Keyword(s):  
Traffic Load ◽  
Load Models

Lastannahmen im Brückenbau – Vergleich von Verkehrslasten für Eisenbahnbrücken aus Lastmodellen und Messdaten/Actions on bridges – A comparison of traffic loads for railway bridges from traffic load models and measured data

Bauingenieur ◽  
2016 ◽  
Vol 91 (10) ◽  
pp. 410-416
Author(s):  
Gerhard Lener ◽  
Johannes Schmid
Keyword(s):  
Measured Data ◽  
Traffic Load ◽  
Railway Bridges ◽  
Load Models ◽  
Traffic Loads

Sowohl bei der ursprünglichen Dimensionierung als auch bei allfälligen Sanierungsvorhaben bedingen die Einwirkungen aus Verkehrslasten die Bauteilabmessungen maßgeblich. In vielen Fällen sind ältere Tragwerke nach heutigen Bemessungsrichtlinien deutlich unterdimensioniert, wodurch im Falle von Erweiterungsmaßnahmen zusätzliche Verstärkungsmaßnahmen im Bestand anfallen. Des Weiteren ist die Beurteilung der Restlebensdauer solcher Tragwerke in der Praxis schwierig, da in der Regel keine Informationen hinsichtlich der realen Einwirkungen aus Verkehrslasten vorhanden sind. Durch diesen unbefriedigenden Zustand motiviert, erfolgt in diesem Beitrag eine nähere Untersuchung realer, messtechnisch erfasster Einwirkungen auf Eisenbahnbrücken. Diese bilden die Basis für Vergleiche der Auswirkungen realer Messdaten und normativen Lastmodellen, die rechnerisch an unterschiedlichen Tragsystemen gezeigt werden. Dabei sind die im Vergleich zu den genormten Belastungen doch maßgeblich geringeren Einwirkungen deutlich erkennbar und liefern damit möglicherweise die Antwort auf die Frage, warum einzelne Eisenbahnbrücken nach wie vor funktionieren, obwohl deren rechnerische Lebensdauer bereits erreicht ist. Des Weiteren zeigt sich das daraus resultierende Optimierungspotenzial bei der Aktivierung von Realtragreserven beziehungsweise der deutlich höherer anzusetzender Lebenserwartung bestehender Tragwerke.

Modified traffic load models for reassessment of short-span highway bridges

2017 ◽  
Vol 109 (4) ◽  
pp. 3385-3393
Author(s):  
Marcel Nowak ◽  
Oliver Fischer
Keyword(s):  
Highway Bridges ◽  
Traffic Load ◽  
Load Models ◽  
Short Span

Extreme value modeling of coincident lane load effects for multi-lane factors of bridges using peaks-over-threshold method

2020 ◽  
pp. 136943322096027
Author(s):  
Junyong Zhou ◽  
Cuimin Hu ◽  
Zhixing Chen ◽  
Xiaoming Wang ◽  
Tao Wang
Keyword(s):  
Extreme Value ◽  
Traffic Load ◽  
Traffic Data ◽  
Peaks Over Threshold ◽  
Experimental Site ◽  
Short Term ◽  
Load Models ◽  
Traffic Loads ◽  
Load Effects ◽  
Value Modeling

Multi-lane factor (MLF) is a probability reduction reflecting unfavorable traffic loads over multiple lanes acting simultaneously on the most adverse position of a bridge. It is one of the key components of traffic load models for bridges. The most recent research established a multi-coefficient MLF model that clearly illustrated the lane load disparity and the probability reduction of their simultaneous actions. However, it used the block maxima (BM) method for extreme value modeling, which requires a large amount of traffic data. This study aims to adopt the peaks-over-threshold (POT) method to obtain more information from short-term traffic data and model the extreme coincident lane load effects (LLEs) for multi-coefficient MLF calibration. First, the multi-coefficient MLF model was reviewed. Thereafter, the bivariate POT method for coincident LLEs modeling using generalized Pareto distribution was proposed and formulated. Critical issues such as bivariate threshold selection and parameter estimation were addressed. Numerical examples were demonstrated to verify and validate the approach. Finally, the proposed approach was applied for calibrating the MLF of an experimental site with four traffic lanes. The results indicated that the coincident LLEs modeling using the POT approach was accurate and more effective than using the BM method when applied to limited data. The calibrated MLFs from the experimental site effectively revealed the lane load disparity of traffic loads over multiple lanes, which is not involved in the traffic load models of current bridge design specifications. Furthermore, the influence of other problems such as weight restriction on coincident LLEs modeling and MLF calibration were discussed. The proposed technique provides a sound approach for multi-coefficient MLF calibration of bridge assessment with short-term site-specific traffic data.

scholarly journals Comparision of constant-span and influence line methods for long-span bridge load calculations

2016 ◽  
Vol 11 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Ainars Paeglitis ◽  
Andris Freimanis
Keyword(s):  
Measurement Errors ◽  
Gumbel Distribution ◽  
Traffic Load ◽  
Design Stage ◽  
Long Span Bridges ◽  
Load Models ◽  
Long Span ◽  
Motion System ◽  
Influence Line ◽  
Long Span Bridge

Traffic load models available in building standards are most often developed for short or medium span bridges, however, it is necessary to develop traffic load models just for long span bridges, because the most unfavourable traffic situations are different. Weigh-in-Motion system data from highway A1 and A3 were used in this study. Measurement errors from data were cleaned using two groups of filters. The first group was based on vehicle validity codes recorded by both systems, if any circumstances might have influenced the measurements, the second group cleaned data using general filters for all vehicles and specific filters for trucks and cars. Additionally, vehicles were adjusted for influence of temperature. Data cleaning increased the average gross vehicle, so it could be considered as a conservative choice. Six traffic scenarios, each with different percentage of cars in the traffic, were made to assess the difference in loads from different traffic compositions. Traffic loads for long-span bridges were calculated using two approaches: the first assuming constant span length, the second, using influence lines from a bridge currently in design stage. Gumbel distribution were fitted to the calculate loads and they were extrapolated to probability of exceedance of 5% in 50 year period. Results show that influence line approach yield larger loads than those from constant-span. Both approaches result in loads larger than ones in Eurocode 1 Load Model 1, however, increase might have been caused by an increase in vehicle weight.

scholarly journals Standardised bridge weigh-in-motion data and its applications in bridge engineering

2021 ◽  
Author(s):  
Jami Qvisen ◽  
Weiwei Lin ◽  
Heikki Lilja ◽  
Timo Tirkkonen ◽  
Mikko Peltomaa ◽  
...  
Keyword(s):  
Bridge Engineering ◽  
Traffic Load ◽  
Bridge Design ◽  
Design Assessment ◽  
Motion Data ◽  
Load Models ◽  
Weigh In Motion ◽  
Bridge Weigh In Motion ◽  
Orthotropic Bridge Deck

<p>Applying actual traffic data in bridge analyses will provide more accurate results compared to the results obtained according to the Eurocode traffic load models. Bridge Weigh-in-Motion (B-WIM) measurements are an excellent tool to produce such data. Using B-WIM data as a part of the bridge design or assessment processes has a large potential, but the lack of widely adopted standardised data format hinders broader utilisation of it. This study proposes a new standardised format to present the measured B-WIM data so that in the future, developed software can directly utilise any available B-WIM data. This would make calculations with multiple different traffic compositions and types straightforward and enable the basis for further utilisation of B-WIM data in bridge design/assessment. To demonstrate the benefits, a fatigue case study of an orthotropic bridge deck was conducted, and the results were compared to ones obtained according to Eurocode FLM 4.</p>

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