Abstract

Baihetan Dam is sited on the lower reaches of the Jinsha river inthe southwest of China between the boarders of Sichuan and Yunnan province.The dam is scheduled to be taken into operation in the year of 2020 with aninstalled generation capacity of 14 GW. In comparison, the Three Gorges damwhich is the world’s biggest dam has an installed generation capacity of22,5 GW.To ensure a sufficient safety evaluation in terms of erosion (scour)formation at the bottom of the plunge pool, pressure simulations in theplunge pool floor in an experimental model at the Department of HydraulicEngineering in Tsinghua University, Beijing, China has been performed. Datafrom two experiments with two different spillway configurations has beenobtained and analyzed together with three earlier performed experiments onthe same experimental model.The results from the five experiments shows the importance of a spillwaydesign that splits the water jet (nappe splitter) before it leaves thespillway lip and that a sufficient water cushion in the plunge pool is used.All four spillway configurations with nappe splitters implemented held ahydrodynamic pressure below the recommended maximum pressure value of 15 mwater head stated by the East Asian Institute of Design, whilst the oneconfiguration with no nappe splitters exceeded the value. Spillwayconfiguration two has six surface spillways with six nappe splittersimplemented; two double nappe splitter at the two center spillways and twosingle nappe splitters at the two outer spillways. In this thesis, thisconfiguration has proven to be the most suitable one in terms of maximumpressure minimization and pressure distribution at the plunge pool floor.