Hydraulic load reduction as a function of depth in a filter layer consisting of logs

To look whether it is feasible to use logs as bottom protection to prevent the formation of scour holes. This research provides an insight in the hydraulic load reduction over depth inside the filter layer and the effect of the filter on the underlying soil. Each experiment consisted of several time steps until erosion occurred. Each time step was on average 1.5 hours. At every time step, the discharge was increased. While increasing the discharge, the water level was emulated to be constant by adjusting the weir at the end of the flume. This led to an increased flow velocity in the flume during the experiment. At every time step the discharge, water level and flow velocities were measured. At the end of each time step, the filter height was measured by the laser and was checked whether erosion occurred by looking inside the sediment trap. If no erosion occurred, a next time step was introduced in which the average velocity in the flume increased. If erosion occurred, the experiment was stopped. Subsequently, the filer layer last bed measurements were done and the next experiment was constructed