Retrofitting of RC Frame Structure Using Performance Based Friction Damper

Abstract

India suffered from many earthquakes over last some decades. Analysis of those earthquake showed that large number of existing structures needs to be upgrade for seismic actions. Performance based earthquake engineering is recent focus of researchers. Present study focused on the seismic retrofitting of existing structures which are previously designed for gravity loads only, by using performance based design philosophy of friction damper. Storey displacement, inter-storey drift, axial force, maximum moment, maximum shear force, base shear variation and effectiveness of dampers are observed for each model and in each direction for seven records of time history earthquakes. Results showed that response of structure are well within the limits of codes provisions. Thus friction damper can be used effectively for seismic retrofitting of structures.Keyword -Retrofitting, Pushover analysis, Friction damper, Time history analysis, Inter-storey drift. I. INTRODUCTIONEarthquake is natural disaster phenomenon in which the motion of the tectonics plate under the earth crust causes the ample amount of energy to be liberated in the form of vibrations. Earthquakes are highly unpredictable and occur suddenly without any prior warning. Approximately 50,000 earthquakes occur in a year over the globe. During the earthquake large amount of energy is transmitted into structure which causes the damage to structures. Amount of damage is depends on pattern by which the energy gets transferred in the structure. India has series of earthquake history, Koyana earthquake strikes the koyana dam with magnitude 6.5 at 10 december 1967, causes 200 peoples deaths and 1500 injuries. Nepal and Bihar earthquake with magnitude 6.6 leads to 1004 people deaths and 16,000 injuries and lots of structural damage. Utterakshi earthquake (1991) of a magnitude 6.6 with PGA as 0.31g, causes 768 deaths and 5066 injuries. Several structures were damage with RC frame and load bearing. Mainly brick infill was damage and slabs got cracked. 30september 1993 killari earthquake with intensity of VIII, more than 30% population was suffered from impact of earthquake. Bhuj earthquake (2001) at Gujrat occurred on 26 january 2001 of magnitude 7.7, destroyed nearly 400000 structures. Divesting effect of earthquake leads to develop and modify the earthquake design codes, which demands higher ductility requirements for safety of the structures. Day by day modification made under code, leads to that the structures become vulnerable which was designed by previous code. Such structures need the retrofitting for updated structural requirement.India has population nearly 130 corers which creates the pressure on government agencies for fulfilment of their basic needs such as shelter, food, health services, and educational services. All such services needs infrastructure such as house for shelter, hospitals for medical services and schools for quality educational services. Large investment is concurred for developing infrastructure facilities so it becomes very important to increa...