Pipe Plunge Pool Energy Dissipator

An extensive program of tests to develop criteria for the design of pipe spillway plunge pool energy dissipators is planned and carried out. The pipe spillway discharge covers a 10‐fold range that includes the minimum full pipe flow and a maximum flow exceeding the practical range, a range of pipe invert heights below and above the tailwater level from −2 to +8 pipe diameters, and a 16‐fold range of noncohesive bed material sizes. The time development and ultimate size of scour holes is determined. The scour hole geometry and other test data are expressed in mathematical equations that can be used to predict the time development and ultimate sizes of scour holes in natural noncohesive soils. These equations can also be used to design riprapped pipe spillway plunge pool energy dissipators. A procedure for the design of pipe plunge pool energy dissipators is presented.