Seismic Analysis Of Concrete Gravity Dam Based On ANSYS

Hydropower is clean and renewable source of energy.Nepal is a country with high hydropower potential.Its development is necessary to meet the energy demand and to boost the economy of the country through irrigation and flood control.To tap the enormous hydropower,high dam has to be constructed.Deep gorges in high Himalayas of Nepal is favorable for the construction of high dam in low cost.Gravity dam has been widely used throughout the world because it is easy to design and construct and reliable too.But Nepal lies in active seismic zone.If the dam failed,it causes huge loss of life and property of downstream areas.So,static and dynamic analysis of dam is must so that the dam will perform well under earthquake load.This paper first discusses on static analysis of dam and seismic theory and seismic design method of concrete gravity dam.This paper uses the finite element software ANSYS to calculate displacement and stress distribution of concrete gravity dam under static load.Block Lanczos has been used for modal analysis to find out the modal shapes and natural frequencies in empty as well as full reservoir condition.Then the response spectrum analysis has been performed under horizontal and vertical earthquake.At last,time history analysis is performed to find the stress for particular point throughout the entire time period.Based on the results obtained,some conclusions are drawn.The crest has the maximum displacement.The stress is concentrated in the region of heel,toe and change of slope.