Influence due to interface in finite element modeling of soil-structure interaction system: a study considering modified interface element

The finite element (FE) modeling of interface in Soil-Structure Interaction (SSI) problem is most important aspect from early days of modeling i.e. during 1960. The overall performance of the structure is completely influenced due to behavior of interface. Such as realistic interface modeling of SSI system subjected to lateral loads leads to appropriate evaluation of lateral sway and base shear stress. During recent times, many modifications have been done in interface modeling such as incorporation of slip and bonding effects. Also the interface joining variable degrees of freedom system (interface for solid to skeletal contact) has come into existence. Still the de-bonding behavior, interface non-linearity as well as modification in solid to skeletal contact has been unexplored in literatures. Hence there is necessity to develop a FE-SSI model and to study the influence of interface in SSI system considering unexplored features. In this paper, an attempt has been made to show the influence due to interface (including de-bonding and non-linearity) in FE modeling of SSI system using modified 5 noded zero thickness interface element. The performance of modified interface element is a novel contribution in present paper. The present study is limited to static loading conditions only. The effect of interface has been studied by determining bending moment, lateral sway, base shear stress and footing settlement in structure. The inclusion of modified interface has improved the performance of structure by reducing the base shear stress and allowing the sway. Also the true redistribution of bending moment has been observed after considering the modified interface.