Abstract

This paper shows the results of experimental tests conducted at the Hydraulic Laboratory of the University of Pisa on the sediment filling effects on non conventional stream rehabilitation structures with low environmental impact, particularly rock chutes or block ramps.

These hydraulic works are used in steep channels in order to regulate the flow and stabilize the bed.

The experimental data were obtained in different flumes. Tests were performed in order to evaluate the main parameters that influence the filling of the block ramps. The parameters that were varied are: the slope, the sediments diameter, the position of block ramps, the inflow and outflow conditions, the modalities of filling and the sediment transport material.

The filling of sediment material along the ramps and the water surface were measured. Furthermore it was investigated the mimimun flow discharge that allow the movement of sediments along the ramp. The goal of this experimental survey is to propose various formula in order to characterize the interaction between sediment transport and rock chutes. Also, this experimenal survey consented to highlight how the natural process of sediment filling over rough bed changes the hydraulic behaviour and the efficiency of the original structure.

Keywords: rock chutes, sediment transport, sediment filling, block ramp