NON LINEAR STATIC AND DYNAMIC ANALYSIS OF A ROCKFILL DAM

Abstract

Limit Equilibrium analysis of dams is used ignoring the deformability characteristics of the material and concentrating on the collapse. mechanism. Nonlinear approaches which establish the constitutive relations and take into account the sequence of construction and the variation of confining pressure provide a more realistic and accurate behavior right upto the point of collapse. It is with this view that the stress analysis of a high rockfill dam is attempted. , The static and the free vibration response of the dam are investigated by linear and nonlinear finite element methods. The static stress analysis is carried out by taking into consideration single and multilift sequence of construction. Effect of variation of confining pressure, material nonlinearity, schedule of construction, sequence of reservoir filling is accounted for in the analysis. The natural period of vibration are studied for the first eight mode shapes. The study indicates that as far as the strecgses are concerned there is a difference in the stress distribution between•single lift analysis and multiple lift analysis. It is also observed that the nonlinear power variation of Young's modulus computed from initial stresses obtained either by linear or by nonlinear analysis yield almost the same time periods of vibration.