Abstract
Dam-toe-footing type training waterway is commonly employed for gate-less gravity concrete dams, and hydraulic design of this training waterway is usually obtained through 3D hydraulic model test. Since the spillway of this type has wide overflow crest with small water-head, depth in a model becomes very thin. This brings the application problem of similarity low of model flow, and deflector is installed on the top of wall for preventing overflow water. Deflector is, however, not suitable for construction, and then appropriate treatment method for measured water surface profile is required. This paper shows the effects of model scale in measured water surface along training wall. Results are obtained by the experiments using some similar and different size models. Errors in measured values by gauge, usually used as a measuring tool in model tests, are also discussed by comparing with the values of electrical measuring instrument.
