Seismic responses of shear wall utilizing three-dimensional dynamic interaction of super-structure with multi-basement and side soil

Abstract:
The common structural design practices usually assume the super-structure to be fixed at the ground level ignoring the presence of either single or multiple basements. This paper is concerned with three-dimensional dynamic interaction analysis of super-structure with basement(s) surrounded by dry side soil and resting on bed rock. More precisely, it investigates the seismic responses of above- and under-ground portions of shear wall as a part of building system. In addition, this full interaction analysis is performed for assessing non-interaction analysis of super-structure with traditional fixed base at ground level. The studied variables include the effect of number of basements (1, 2, 3, 5) and density states of side soil (loose and very dense). The building is idealized by shell and frame elements; while the side soil is idealized by 8-noded brick elements and repeatable side boundaries to allow for the induced seismic waves to dissipate from the side boundaries without being reflected back into the soil domain. Further objective is to assess a proposed partial interaction simulation without accounting for the side soil modeling against the full interaction one to reduce the analysis complexity and computer needed capacity and run-time. This study is carried out using linear elastic transient dynamic three-dimensional finite element module of ADINA program under the effect of Northridge-1994-USA Earthquake applied at the bottom boundary (bed rock surface). The results showed minor effect of side soil conditions and its absence on seismic responses of the above- and under-ground portions of shear wall in buildings of (3-basemnts or less). In addition, the highest shear force value in the whole shear wall is developed at first basement level. Further, the fixity assumption of building at ground level develops conservative seismic responses of the shear wall.