Seite - 1085 - in Book of Full Papers - Symposium Hydro Engineering

FURTHER IMPROVEMENTS OF SPILLWAY INTAKE When the existing overflow piers were removed, research for a new design was carried out. The aim was to further eliminate the pressure pulsations on the spillway structure while not decreasing the capacity of the spillway. A design of five-piers based on the similarity with other existing bell-mouth spillways was proposed and tested (Fig. 6). The six piers variant was also considered but it resulted in increase in pressure pulses throughout the tested flow range. SUMMARY This paper presents the hydraulic research of the existing bell-mouth spillway at the Jirkov Dam in the Czech Republic and the improvements proposed to increase the hydraulic performance of the structure. Proposals comprise the new design of the overflow piers and the rounding of the bottom of the vertical shaft. The improvements were proposed and tested on a physical model by the Czech Technical University in Prague, Faculty of Civil Engineering. Rating curve was derived for the existing spillway design as well as for the proposed layouts. Proposed layouts showed an improvement, particularly Fig. 7 Model of bell-mouth – designed overflow piers 1085