SEISMIC RETROFITTING OF REINFORCED CONCRETE BUILDINGS

Abstract

Recent earthquakes in many parts of the globe have revealed the issues regarding the vulnerability of existing buildings. The existing building structures, which were designed and constructed according to earlier code provisions, do not satisfy requirements of current seismic code and design practices. Many reinforced concrete buildings in urban regions lying in active seismic zones, may suffer moderate to severe damages during future ground motions. Therefore it is essential to mitigate unacceptable hazards to property and life of occupants, posed during future probable earthquake. The mitigation of hazards is possible by means of seismic retrofitting of inadequate existing building structures. The present dissertation work deals with the seismic retrofitting of an existing fourteen storied reinforced concrete building located in seismic zone IV. The study comprises of seismic evaluation and retrofitting of R. C. building by using steel bracing and infill masonry walls. The seismic evaluation is carried out on the basis of two-dimensional elastic, linear and dynamic analysis. The exterior frames are studied for comparison of performance of methods of retrofitting. The computer software package STAAD III (1997) is used for dynamic analysis.