Modelling tests for a new kind of meandering ramp

A new type of meandering ramp is to be built in a section of the River Wiese to facilitate the movement and connectivity of aquatic animals. Researchers from BFH are using a model to investigate and optimise the concept.

Factsheet

  • Lead school School of Architecture, Wood and Civil Engineering
  • Institute Institute for Infrastructure and Environment IIU
  • Research unit Geotechnics and Special Civil Engineering group FGGS
  • Funding organisation Others
  • Duration 01.01.2022 - 31.10.2023
  • Project management Prof. Dr. Jolanda Jenzer Althaus
  • Head of project Prof. Dr. Jolanda Jenzer Althaus
  • Project staff Gianluca Flepp
  • Keywords Hydraulic engineering, modelling tests, revitalisation

Situation

As part of a revitalisation project, the Canton of Basel-Stadt is building a new type of meandering ramp in a section of the River Wiese (km 2+000.00 to 2+215.00, longitudinal gradient of J = 1%) in an effort to facilitate the movement and connectivity of aquatic animals. The ramp’s main current will have a back and forth pattern similar to that of a traditional meandering ramp and will mini-mise riverbank erosion. However, the construction method will be different: unlike a traditional meandering ramp, the back and forth movement of the cur-rent will not be generated by a series of alternately inclining and declining bars, but by a sequence of almost interlocking groynes on either side of the river. The new ramp will create a distinct low-water channel, facilitating connectivity in aquatic animals that travel close to the riverbed. Due to the nearby groundwater protection zone, scour formation may still be possible but will be limited in depth. The ramp is unlikely to silt up and should resist flooding.

Course of action

On behalf of the Canton of Basel-Stadt, BFH researchers are using a model to review and optimise the new meandering ramp and ensure it meets the specified requirements. The researchers were given data from the river section and used this to create a realistic 1:30 scale model roughly 14 metres long and 4 metres wide. The model incorporates structural elements of the meandering ramp, whose influence on the current and erosion will be monitored in testing.

Visualisierung der Strömung mit der Pendelrampe.
Die Hauptströmung soll auf der Rampe hin- und herpendeln.
Logo WieseVital
Das Projekt ist Teil des Revitalisierungsprojekts WieseVital.