Retrofitting of Columns of an Existing Building by RC ERP FRP SFRC and Steel Jacketing Techniques

Abstract

Retrofitting is a technique to enhance the structural capacities including the strength, stiffness, ductility, stability, and integrity of a building that is found to be deficient or vulnerable. It can effectively raise the performance of a building against earthquake to a desired level, and to even satisfy the requirements of an upgraded design seismic code. The building need not be deteriorated or damaged. The retrofit is also intended to mitigate the effect of a future earthquake. In this project, an effort is made to elaborate the procedure of providing concrete jacketing to the column as per guidelines of IS 15988: 2013. It is seen that the overall performance of the column significantly improves after jacketing. Seismic protection of buildings is a need-based concept aimed to improve the performance of any structure under future earthquakes. Earthquakes of varying magnitude have occurred in the recent past in India, causing extensive damage to life and property. Some recently developed materials and techniques can play vital role in structural repairs, seismic strengthening and retrofitting of existing buildings, whether damaged or undamaged. The primary concern of a structural engineer is to successfully restore the structures as quickly as possible. Selection of right materials, techniques and procedures to be employed for the repair of a given structures have been a major challenges. An existing four storey RC framed residential building situated in Patna, Bihar is taken for this study. When this building was analysed for expected seismic loads i.e four storey, none of the columns failed, but it was proposed by owner to add two more storey to existing frame without any change in existing structure. When five storey building was modelled and analysed for same seismic performance ,6 columns failed & when one more storey was added, 19 columns failed . The failed columns were retrofitted using RC, FRP, SFRC, STEEL Jacketing. All these jacketing techniques were also compared in terms of economic ease of application & change that was made in original space of building due to use of these jackets. After comparing it was found that STEEL Jacketing is best in terms of all of above set parameters.