ME Civil (Structure) Second Year Student

Abstract — Many existing buildings lack the seismic strength and detailing requirements of IS: 1893-2002 and IS: 13920-1993, because either they were designed for only gravity loads or built prior to the implementation of these codes. Hence it is required to assess the performance level of such buildings for safety of the structure during earthquake. In present study three buildings 8, 12 and 16 storied are considered. They are designed for only gravity loads according to IS: 456-2000 without ductile detailing. Seismic evaluation of these buildings is carried out with nonlinear static pushover analysis using SAP2000 software. Performance points and performance levels of these buildings are determined by capacity spectrum methods. All three buildings are found in life safety to collapse prevention (LS-CP) range for design basis earthquake condition. Then various retrofitting schemes viz. steel X braces, infill walls, and shear wall are employed for strengthening of these buildings, performance level requirement of operational to immediate occupancy (B-IO) under design basis earthquake is aimed at. Idealized force-displacement capacity curve is implemented to evaluate various seismic parameters from pushover curve which is based on the method recommended by FEMA 356. The results are compared based on performance point, hinge formation pattern, yield strength and lateral stiffness. The results show that there is no unique solution and several different strengthening schemes can be provided to give adequate performance. Most increase in the lateral strength and stiffness is related to using infill wall and shear wall