Objektspezifische Verkehrslastansätze für Straßenbrücken: Ein wichtiger Baustein für erweiterte Beurteilungskonzepte in der Brückennachrechnung

Site-specific traffic load models for road bridges – an important tool for advanced evaluation strategies in bridge reassessment. Definition and calibration of traffic load models is usually done on the level of structural demands (resulting from actual load impact). Consequently, such load models are affected by both the characteristics of traffic on site, and the structure itself. Starting from universal load models – as specified in codes and guidelines for general use in engineering practice and reasonable for application in design of new bridges – consequent consideration of site-specific characteristics regarding local traffic and structure allows for a more realistic representation of the actual traffic load demand and hence, possible reductions in the considered load level for application in reassessment for a specific structure. Site-specific load models are developed using a comprehensive procedure based on numerical traffic simulations (analysis of various possible traffic scenarios for robustness of load models) and ideally calibrated with real measurements on site. A stepwise approach for application in engineering practice is proposed, to allow for development of modified load models with a variable degree of considering site-specific characteristics, depending on desired cost and expected benefit. Results from primal analysis with an exemplary bridge structure already reveal the potential of this approach.