EFFECT OF CANYON GEOMETRY AND CURVATURE ON RQCKFILL DAMS UNDER EARTHQUAKES

Abstract

Earth and Rockfill dams form a lifeline of our economy. Any savings in their construction cost due to sophisticated analysis is highly desirable. Also desirable is an accurate estimate of the parameters, ( viz, time periods and frequencies, for the corresponding mode shapes), governing their design and analysis. The study presented makes an effort to analysis the unexplored angle, of the variation of curvature to examine the changes in the time period of the structure, in a sophisticated manner using Cosmos Software which employs the finite element procedure for analysis. The results of the analysis will indicate the dependence of the frequency on the curvature effect for the dam. The analysis has been presented for various curvatures and geometry of the assumed section of the dam for different shapes like semicircular, trapezoidal and triangular. The capabilities and the limitations of the package in analyzing such problems have been studied. Although very limited capabilities of the software have been explored, the study has indicated that the preprocessor, solver and post processor are very powerful but there are still some limitations. Preprocessor of the software is not always very powerful. To have the node compatibility at the curved portions model has to be planned earlier such that two entities touching each other have one common sub entity. As a whole the package is quite robust and capable of handling the hydraulic structures.