Real traffic load models for bridges (REAL-LAST)

The currently existing bridges on the road network were erected on the basis of the national codes and standards valid during the planning process. A high percentage of bridges are 40 years or older. The traffic load models depicted in EN 1991-2 are based on traffic measurements conducted in 1986. New technologies in the measurement of traffic allow a better recording of the real traffic behaviour. They allow to define the existing load models better and more accurate and enable a continuous evaluation and quantification.

The project REAL-LAST develops and verifies algorithms for route-specific adaptations of the current traffic load model and calibration factors for LM1/ELM (x) according to EN 1991-2. The algorithms are based on different databases with the goal to back calculate existing bridges in the highway network of Germany, Austria and Switzerland.

The workflow consists of different modules: fusion of traffic data, traffic simulation, analysis of bridges and calibration of the load models. ETH Zurich investigates if and how the route-based load models are influenced by the chosen representative road section. It will be investigated, what the gain of accuracy will be, if bridge parameters (e.g. material, type of cross section, static system, span length) are taken into consideration.