Analysis and Design of Reinforced Concrete Frames Under Retrofitting Condition By Using Steel Bracings In ETABS

Abstract

There is a global consensus that natural disasters are occurring more frequently in the recent times. This may be majorly due to our inability to control the hazards from causing colossal damages to structures, properties and life. A major portion of peninsular India is hit by natural disasters among which 58% is prone to earthquakes. Himalayan region, Indogigantic planes are also more vulnerable to earthquakes.  Indian subcontinent has suffered some of the greatest earthquakes in the world with magnitude exceeding 8.0. RC framed buildings are the most commonly found in Indian scenario, constituting to a major percentage among the total buildings in the country. This may be due to the ease in construction and vertical expansion of such buildings, in addition to the superior seismic performance as compared to the masonry buildings. However, these RC buildings are also suffering extensive damages during earthquakes in India, raising concern over their safety and the safety of the incumbents as well. Poor workmanship is identified as the main reason of failure of RC buildings during earthquakes in India. Realizing this need, a detailed numerical investigation is taken up in this work on a eleven (G+10) storied RC framed building, for seismic zone-3.The effectiveness of 3 types of column jacketing viz., RCC, STEEL and FRP, in contributing for better seismic performance of the building is checked in terms of bending moments, axial forces developed in the columns in various locations of the building. For each material, one model is tried which is closer to the field practice where the jacket is given connections with the existing column in the form of shear connectors, welds etc.