Seismic Upgradation of a G plus III Storeyed Existing Residential Building Located in Jammu

Abstract

Past earthquakes in India have revealed that majority of the buildings are not designed Earthquake Resistant. Generally, buildings are designed taking into account only the gravity loads. Also, the current design seismic codes are not fully practiced while designing a building. Hence, a higher degree of damage is expected during an earthquake if the seismic resistance of the building is inadequate. Thus, for these types of buildings, Retrofitting gives out the best possible way in order to minimize the future damage caused due to vibrations produced by an earthquake. This thesis describes the seismic retrofitting of an existing G+III residential building located in Jammu. Since the building lies in J&K which is under severe seismic zone i.e. Zone IV and V, it needs to be designed seismically resistant. Static and dynamic analysis of the building is performed and the required and provided area of steel of all the structural members are compared and checked. Retrofitting is being done for the deficient columns of the building. The step by step retrofitting techniques are incorporated in this. The existing building is retrofitted using various techniques like jacketting of columns and addition of shear walls. Jacketting methods include RC jacketting, Steel plate Jacketting and FRP Jacketting. All these jacketting techniques are compared based on the parameters of safety, economy and onsite-feasibility. FRP jacketing, being light in weight, does not increase seismic weight of building but it improves lateral strength considerably. Steel jacketing, has a comparable cost with RC jacketing but giving better results. It is lighter in weight too. Hence, FRP and steel jacketing prove to be the best technique for retrofitting of weak concrete columns. FRP and steel jacketting provides more protection whereas RC jacketing is more economical.