Author(s): Thomas Gschnitzer; Bernhard Gems; Markus Aufleger; Bruno Mazzorana; Francesco Comiti
Linked Author(s): Markus Aufleger, Bernhard Gems
Keywords: Bridge clogging; Scale model test; Driftwood; Log jam; Mountain rivers
Abstract: The present paper deals with the physical modeling of bridge clogging processes due to driftwood transport in mountain rivers. Scale model tests were conducted in the hydraulic laboratory of the University of Innsbruck, Austria. A rectangular channel and a bridge with guard rails were built into an inclinable flume to study the phenomenon. The driftwood was classified by different length groups, furthermore smooth trunks and trunks with branches were differentiated for the tests. Tests with similar boundary conditions were repeated numerous times to account for the variability of the motion of the trunks and its interaction with the bridge. The tests show how the clogging probabilities increase both with the length of the driftwood and the presence of branches. The influence of the channel slope and the water level on the clogging probabilities was noted. Hydraulic effects like damming and backflow depend mainly on the initial hydraulic boundary conditions and the characteristics of the clogging. The outcomes of the present paper highlight the results of the model tests that were conducted in our laboratory at the University of Innsbruck, Austria. These results contribute to a better understanding of the influencing parameters on bridge clogging processes.
Year: 2013