Evaluation of Amplification Factor for Open Ground Storey RC Structures with Infill Openings in Upper Storeys.

Reinforced concrete structure with infill wall provides better strength, stiffness and energy dissipation capacity compared to bare frame while analyzing the models. Strength and stiffness of the structure decrease when percentage of openings in a wall increases. Open Ground Storey Structure (OGSS) shows very poor performance in earthquakeprone areas as discussed in past researches. Literature shows that damages in members of soft storey structures are dependent upon their relative stiffness with respect to adjacent storeys. When the effect of Soil Structure Interaction (SSI) is included, displacement demand and natural period will be high, and also decrease in base shear occurs which is not beneficial (Goud and Ramancharla, 2017). The paper studies the seismic response of fully infilled and OGSS models with different percentages of wall openings for both with and without SSI effect. The analysis of different models is carried out in software ETABS-2009. The main parameters investigated are natural period, base shear, displacement and storey drift. Also, magnification factors for soft storey members with different percentages of openings in upper storeys are found. It is found that magnification factor decreases as the percentage of openings in wall infill increases. [ABSTRACT FROM AUTHOR]