Controlling a side weir without gates

Josef Schneider, Matthias Redtenbacher, Franz Brenner

Tuesday 30 june 2015

9:15 - 9:30h at Africa (level 0)

Themes: (T) Water engineering, (ST) Experimental facilities and instrumentation

Parallel session: 4F. Engineering - Instrumentation

The on-hand contribution gives an insight in an innovative way to control the discharge of a side weir. The purpose of the side weir is to relief water of a little river into a retention basin during floods. The maximum inflowing discharge of 60 m³/s has to be divided in 18 m³/s remaining water in the river and 42 m³/s relieved water. The remaining discharge of 18 m³/s has to be ensured at all time. A further determining factor is the requirement that moving parts like gates or similar must not be installed and log jams have to be avoided. A physical model test - scaled 1:20 - has been performed in the hydraulic laboratory of Graz University of Technology to find a solution for the described problem. A combination of culverts located at the downstream area of the side weir enables a free flowing discharge up to about 16 - 18 m³/s which starts to retain and to spill over at this discharge. Finally, the remaining water amount in the downstream river section stays relatively constant with increasing inflow and at maximum discharge the problem specifications are fulfilled.