SEISMIC ASSESSMENT OF STRUCTURES USING P-DELTA EFFECT

Abstract

Earthquake is the most catastrophic and erratic natural occurrence which causes huge devastation to human lives as well as structures. Earthquake forces produced during earthquake advances to severely damage the structural elements and sometimes even their failure. Also, urbanization is growing rapidly, existing land for building is becoming less and costlier. So, popularity of Tall Buildings is increasing. Based on guidelines of IS:16700-2017, the P-Delta analysis must be used when analyzing tall buildings, which is also an iterative type of method. When a member is loaded axially and a lateral force act on it but it remains in place then moment is only produced by this lateral load, but when the member gets deflected by Δ, with initial moment still acting on it, a secondary moment starts acting on it due to this deflection which is called as P-Delta effect. In most of the structures with elements which are applied with axial load, the non-linear effect which is called as P-Delta occurs. More the height of building, more is lateral seismic load. With increase in height of the structure P-Delta effect becomes very significant. In this work we have taken 3 RC building models of residential complex of East Delhi which comprise of G+4, G+10, and G+22 storeys. All three models have same dimensions of beams and columns and slabs. The work is done in two phases. In one phase analysis is done excluding P-Delta effect, while in second part P-Delta effect is considered. We have reported the storey displacement and storey drift of all 3 models in both the cases. Results show significant difference in storey displacement and storey drift with and without P-delta effect. For future considerations, a correlation analysis is done and correlation factors are determined.