EFFECT OF SOIL- STRUCTURE INTERACTION ON HIGH RISE R.C REGULAR FRAME STRUCTURE WITH IRREGULAR BAYS SUBJECTED TO SEISMIC LOAD

M.Pavan Kumar, G.T.Naidu, T.Ashok Kumar

Abstract: Reinforced concrete building structure consist of horizontal member (beam & slab) and vertical members (columns & walls), and supported by foundation. The structure is subjected to loads of self-weight, live load, wind load and earthquake load etc. The structural strength of slab and the brick walls is not normally considered in the analysis of the structure Generally the foundation support is assumed as either hinged or fixed support, while foundations transmit the load to the soil medium which undergoes a settlement (vertical) depending on the loads from the structure and characteristics of the soil medium, causing the additional forces in structure. However, this effect is normally neglected in the structural analysis due to its complicated analysis. An attempt is made to analyze the structure considering the foundation soil settlement as define like soil medium by spring. The structure is analyzed for various seismic zones of India. (II, III, IV,&V), sub grade modulus of soil (Gs) from 12000kN/m3 to 60,000kN/m3 .The results of the above analysis are used to study the effect of soil – structure interaction on horizontal displacement ‘??x’ at each floor, and vertical displacement ‘??y’ at the supports of a building. From the study, it is observed that the maximum percentage of variation in x- trans is 337 percentage with respect to fixed support condition at sub grade modulus of 12,000 kN /m2 /m at seismic zone V and the maximum percentage of variation in y- trans is 1420 percentage with respect to fixed support at sub grade modulus 12,000 kN/m2 /m at seismic zone V. From pilot study, concluded that effect of soil – structure interaction has to consider especially for lower sub grade modulus of soil at higher seismic intensities

Keywords: Soil structure interaction (SSI), R.C.frame, Seismic load, High rise buildings etc…

DOI: https://doi.org/10.15623/ijret.2015.0410022