This study considers the hydraulic design of a shaft spillway with a constriction at the upstream end of the vertical bend. The effect of key factors relating to the capacity of the crest, shaft and tunnel is assessed using hydraulic model investigations of several spillways and available experience from other relevant research. As a result, new expressions for the discharge and velocity coefficients have been established. An algorithm for the design procedure, based on previous experience, is also presented.

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This paper presents two-dimensional (2D) and three-dimensional (3D) numerical models for unsteady phased thermal analysis of RCC dams. The time evolution of a thermal field has been modeled using the actual dam shape, RCC technology and the adequate description of material properties. Model calibration and verification has been done based on the field investigations of the Platanovryssi dam, the highest RCC dam in Europe. The results of a long-term thermal analysis, with actual initial and boundary conditions, have shown a good agreement with the observed temperatures. The influence of relevant parameters on the thermal field of RCC dams has been analyzed. It is concluded that the 2D model is appropriate for the thermal phased analysis, and that the boundary conditions and the mixture properties are the most influential on the RCC dam thermal behavior.

Concrete (RCC) is a special concrete mixture with low cement content, frequently used for concrete gravity dams. This paper deals with the 3D finite element model for unsteady phased thermal-stress analysis of RCC dams. Model calibration and verification has been done, based on the in-situ measurements of the Platanovryssi dam. The study has been done using the actual dam shape, RCC time schedule, and material properties. The results prove that the recommended 3D model enables a reliable thermal-stress prediction and transversal joint distance computation for an RCC gravity dam.

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Complex hydrological models find adequate formalization in co-nodal systems, given the abundance, multiplication, dynamics, relations of elements (hubs and nodes) and systems (basins and rivers), as well as chronologies. Hydrological models function on the principle of nodes and orientations. Hypo-cycloids (in the text: h-Cycloids) are time-spatial categories; the subject of hydrodynamic nonlinear analysis, they do not exist entirely realistically as recent flows, but are present only partially, phased, as partial flows. Hypo-cycloids are formed by summing cycles with a combination of overlapping and alternating flows. Cycles are time-spatial categories of co-nodal reconstruction. Fluvial dynamics is logically composed of nodal sets, hub systems, and junctions that are polyvalues (polyvalent, multi-oriented, cyclic) of a diverse model rather than a single-oriented output of just a simple physical model. The chapter examines four of the world's largest interfluviums: Parana-Paraguay, Euphrates-Tigris, Mississippi-Ohio, Danube-Tisza.

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