Seismic Evaluation of RC Framed Structure Using P-Delta Analysis

The Buildings, which appeared to be strong enough, may crumble like houses of cards during earthquake and deficiencies may be exposed. Experience gain from the recent earthquake of Bhuj, 2001 demonstrates that the most of buildings collapsed were found deficient to meet out the requirements of the present-day codes. Due to wrong construction practices and ignorance for earthquake resistant design of buildings in our country, most of the existing buildings are vulnerable to future earthquakes. Considering these facts, it is imperative to seismically evaluate the existing building with the present-day knowledge to avoid the major destruction in the future earthquakes. The present study deals with the evaluation of R.C framed buildings using inelastic method (P-Delta Analysis). P-Delta Analysis is Non-Linear Static Analysis, so the structural response is incorporate the additional response produced due to simultaneously action of lateral and gravity load on undeformed as well as deformed geometry. An overview of P-delta analysis procedures is presented first. Finite Element Software STAAD. PRO is used to perform the P-Delta Analysis and Variation is observed in response. A symmetrical regular RC frame building is analyzed using STAAD.PRO for the procedure development as per I.S 1893:2002 (static and dynamically). Then, Seismic Evaluation is performed on same modal for including P-Delta effects. The first part as without considering P-Delta effect and in the second part it is considered. The results have been compared for these three Analysis and necessity is suggested for incorporating the effect in general RC design practice and development of provisions in Indian standards.