THEORETICAL ANALYSIS ON HYDRODYNAMIC PRESSURE IN INTAKE STRUCTURES OF DAM UNDER FLOW AND EARTHQUAKE

摘要

The theoretical analysis on the hydrodynamic pressure under earthquake is well known such as Westergard's theory, but the one in intake structures of dam is not yet clear. In an intake structure with rectangular section, water flows in parallel to wall in vertical direction and earthquake acts perpendicular to wall in horizontal direction. This intake structure constructed by gates is used for selective intake of water from dam, such as warm water in surface zone in dam is supplying to rice fields in Japan especially in spring term. The results by theoretical analysis show that if the velocity of water is higher than the intensity of earthquake, the hydrodynamic pressure becomes high. The theoretical analysis under this flow condition is made and the intensity of hydrodynamic pressure can be shown by several graphs. The results are written by parameters such as velocity of water flow in intake structure, amplitude of earthquake motion and frequency of earthquake.