The aim of the project was to develop a bed stability structure at the same riverbed level for the transition from non-widened to widened river stretches in order to avoid erosion upstream. The stepless design also enables good ecological patency.
The Rough Carpet consists of large edged stones placed on the riverbed. The increased flow resistance increases the water level upstream and thus reduces the bed load transport capacity. The size of the stones and the length of the Rough Carpet can control the effect.
Project partners were the University of Natural Resources and Life Sciences (BOKU), Institute for Water Management, Hydrology and Hydraulic Engineering as well as iC group (iC consultants Ltd.).
The Austrian Research Promotion Agency (FFG) supported the project.
The project was divided into several phases that were linked together in the sense of hybrid modelling. Phase 1 included physical model tests in the hydraulic engineering laboratory at BOKU with different configurations of Rough Carpets and different model scales (basic tests without the addition of bed load). Phase 2 used the results from the physical model tests for the calibration of numerical models in order to be able to carry out optimizations in this way. Phase 3 were physical model tests with bed load supply, which were carried out in our test facilities. In this series of experiments, different amounts of bed load (bed load deficits) were simulated and the transition sections at the beginning and end of a Rough Carpet were examined.
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© Christoph Roscheck, 2015 zoom gallery -
© Christoph Roscheck, 2015 zoom gallery
The following two pictures show the bed load supply (first picture) and the surface of the rough carpet with high bed load transport (second picture).
The results of this research project were published in 2016 (in German):
Sindelar, Ch., Pfemeter, M., Roscheck, Ch., Sattler, S., Hengl, M., Habersack, H. (2016). Der Rauteppich – Untersuchungen zu einem neuartigen, hydraulisch wirksamen Bauwerk zur Reduktion von Sohleintiefungstendenzen. Symposium Wasserbau – mehr als Bauen im Wasser, 29.6. bis 1.7.2016 in Wallgau. Berichte des Lehrstuhls und der Versuchsanstalt für Wasserbau und Wasserwirtschaft der TU München, Nr. 134.
You will find this publication in German language as PDF file under Downloads. We have this file from www.freunde.wb.bgu.tum.de (download in December 2017).