ABSTRACT
Crest spillways are most often found with mass concrete dams. They are also constructed with other kinds of concrete dams. A dam with an overflow section through its own body is the most economical solution for the evacuation of floodwaters in the course of service of the hydraulic scheme. Figure 26.1 shows sketches of the most frequently used spillways through the body of concrete dams. Illustrations (a) and (b) presents spillways with the practical profile that is most often applied in practice. These spillways ensure uniform overflowing of water without dynamic impacts. Types (c) and (d) are spillways with a free overfall jet (nappe), employed for an arch and buttress dam. Type (e) is a spread profile of a spillway with a practical profile that is employed with weaker foundations, as well as the application of gates requiring a wider crest, while type (f) is a spillway with a wide crest sill.
