Lyon urban area rail bypass - Crossing over the river Rhône

Measuring the hydraulic impact of bridges on flows during floods.


Lyon urban area rail bypass – Crossing over the river Rhône (France) - Client: RFF - Scale: 1:80

In the context of the Lyon urban area rail bypass project, the owner and manager of the French railway network, Réseau Ferré de France (RFF), commissioned Artelia to perform a physical model study of the bridge carrying the new railway line across the Rhône, located at the eastern end of the Miribel Jonage island near the town of Niévroz, to the East of Lyon.

Purpose of the physical model

  • Qualitative and quantitative characterisation of the hydraulic impact of the planned structures on flows during floods
  • Optimisation of the structures and the construction requirements in order to minimise these impacts

Stages in the study

  • Calibration of instrumentation
  • Lyon rail bypass | Artelia
    Lyon rail bypass
    Testing in the existing configuration
  • Adjustment of the model
  • Testing in the design configuration
  • Testing in the optimised design configuration.

Description of the physical model

  • Representation of the Rhône and its flood plain
  • Bridges over the Rhône for the A432 motorway and the high-speed railway line, then the planned rail bypass (viaduct and relief structures)
  • Continuous measurement and recording of the levels by 22 ultrasound sensors
  • Automated adjustment of the downstream level by 4 hinged flaps.

Design flow rates

Represented length of the river Rhône

Total represented area

100-year flood: 3635 m3/s

1000-year flood: 4710 m3/s

4 km

3.6 km x 2.4 km

(model: 45 m x 30 m)