SEISMIC EVALUATION OF RCC FRAMED STRUCTURES SUBJECTED TO ELEVATED TEMPERATURE

Abstract

To implement performance based engineering philosophies in seismic design of civil structures, seismic engineers require new seismic design provisions to perform non-linear analysis of the structures. These analyses can be done either by non-linear Dynamic (time history) analysis or non-linear static pushover analysis. As non-linear dynamic analysis is time consuming, complex and impractical for general use, non-linear static pushover analysis is gaining popularity because it gives a good balance between accuracy and simplicity. In the present study, seismic evaluation of RCC framed structure subjected to elevated temperature has been studied using pushover analysis.SAP-2000v12, a non-linear package, has been utilised to create the model as well as to carry out the analysis. In the present study, pushover analysis has been performed on two buildings. One is an experimental set-up and the other is a realistic building. The building has been designed following IS: 456-2000, IS: 1893(Part-1)-2002 and IS: 13920 -1993. An experiment was conducted by BARC at SERC Chennai to obtain the experimental pushover curve of a 3-storey (G+2) RC bare frame structure. In the present work, analytical result has been validated with that of the experimental result. It is then assumed that the structure is subjected to elevated temperature considering the material properties at elevated temperature, available in literature. M-cI3 curve has been obtained using a programme in visual basic as well as by section designer package in SAP2000. User defined hinges has been assigned on the experimental set-up model and auto hinge has been applied in the realistic building model. Capacity (pushover) curves of the building subjected to 200°C, 400°C, 600°C and 800°C have been obtained and compared. Performance point of the building subjected to elevated temperature in different seismic zones has been obtained and shown in the work. Finally, the comparison of Drift ratio, Ductility demand and performance of the structure at different seismic zones of our country has been done.