Author(s): P. Balayn; A. Paquier; M. Lapuszek
Linked Author(s):
Keywords: Sediment transport; Sewer; 1-D model; Calibration; Grain-size distribution
Abstract: A 1-D sediment transport model is detailed. The classical model that represents sediments by a mean diameter D50 is completed by a complementary parameter, the standard deviation (that is defined by the square root of the ratio between D84 and D16). Solving de Saint Venant equations to take into account the high stages and using this sediment model provides a method to simulate the evolution of the bottom of the river at a rather global scale. It is necessary to add some coefficients that will be calibrated on field cases in the same way as a model with various classes of sediments requests the definition of the interaction between the various classes. The example of a flushing in a sewer collector is explained. The calibration of the model for the sediment transport is based on the parameter that expresses the lag in space between the sediment transport capacity and the sediment discharge. The erosion of the sediment layer by successive waves is conveniently modelled but the evolution of the water levels and velocities are not accurate. If the simple 1-D model is kept, it is necessary to change the friction coefficient with time and space because of the bottom variation and of the sediment concentrations, in a similar way as done for bed forms.
Year: 2003