COMPARISON BETWEEN RESULTS OF MATHEMATICAL and PHYSICAL MODELS IN CONVERGENT SPILLWAY (CASE STUDY: CONCRETE SPILLWAY OF ZOLA ROCKFILL DAM

The function of the spillways in dams is to discharge the flood and superfluous water. Taking into view that flow of water through the spillways is often an isometric and complex issue, therefore, the theoretic solution of the problem is rather difficult, and a project may be hard to find whose physical model and laboratory tests are not performed well ahead of constructing the structure. The aim of the present abstract article is to make a comparison between the studies on mathematical and physical models of spillway, and to consider the importance of the parameters studied for the submission of intended design. Inter alia , Zola dam spillway is pointed out here. That spillway is 43.5 m wide and approximately 230 m long. The spillway chute was initially 43.5 m wide, but later, for some technical and economical reasons of the project, its width was reduced down to 15 m, and it was designed convergent. For the unique topographical conditions of the area, the chute was designed with two slopes of 1% and 72%.The results of studies on the tests of physical model revealed that because of the rather slight slope of the first part on the chute (slope of 1%), there will be the possibility of a hydraulic jump on the chute, and potential return of water towards spillway ogee. Thus, for the remedy of the existing situation, exhaustive studies were performed on the basis of mathematical model; to remedy and correct the geometry of spillway structure and chute, and then the new geometry of the spillway were controlled against the physical model. The present abstract article deals with a comprehensive description of the above-mentioned process of studies, and a comparison made between the mathematical and laboratory results.