CONTACT ELEMENT ANALYSIS OF A TYPICAL CONCRETE GRAVITY DAM

Abstract

As we know that dams were the earliest man made massive structures which attracts a lot of external interests other than engineering. Before a dam has to be constructed lot of studies has to be made to make it as safe throughout its whole life especially from the socio—economic condition. Although it was not always possible to construct a dam on safe locations from engineering and geological point of view. So it was necessary to consider the safety as much as possible. The analyses has been worked our considering all unfavorable conditions of foundation beneath the dam and assess the behavior and safety of structures like dam, which was having destructive potential. For this study a typical dam has been taken and it was modeled as per geometry. Two types of model namely 2D and 3D block has been made along with the foundation media beneath the dam. Analysis was carried out for two cases first one, considering the displacement between dam and foundation was continuous and secondly, considering effect of discontinuity in displacements between dam and foundation were adopted. Analysis was done considering foundation was flexible as well as rigid. The effect of discontinuity in terms of interface was replicated using finite element software Ansys v 11. The displacements and stresses were reduced as increase in elasticity modulus of foundation media. Also 2D model has higher value of displacements as compared to 3D model. The result from the analysis indicates that the continuous and discontinuous models differ marginally under static condition but the result was considerable under dynamic consideration. Generally the introduction of contact does modify the behavior of the dam due to additional non linearity but the lateral destabilizing forces were much smaller than the restoring forces.