INFLUENCE OF THE SPUR DIKE PERMEABILITY ON FLOW AND SCOURING DURING A SURGE PASS

An experimental look on the influence of the structure permeability on flow pattern and local scouring process near a spur dike is presented in this paper. Detailed measurements of pressure and scouring action, performed in cases of permeable and impermeable structure, gave materials to compare such parameters as water level, excess pore pressure, seepage force and final scour profile. Significant differences among cases were noticed in all those factors. The permeability of the spur-dike was recognized as a very important feature that results in preserving the riverbed from scouring. The values of all other parameters which may promote scouring were noticeably smaller. The experiments were conducted simulating conditions of a surge flow, which additionally exposed all measured parameters. The disaster-like type of flow showed very significant differences between two examined types of spur dikes.