Author : Minakshi V. Vaghani, Sandip A. Vasanwala and Atul K. Desai

A higher degree of damage in a building is expected during an earthquake if the seismic resistance of the building is inadequate. The decision to strengthen it before an earthquake occurs depends on the building’s seismic resistance. The structural system of deficient building should be adequately strengthened in order to attain the desired level of seismic resistance. Though considerable research was carried out on performance of existing- and retrofitted-‘GLD’ and ‘Ductile’ structures, studies on the behaviour of ‘Nonductile’ one, which falls between these two prominent levels of design concept, are inadequate. Indian Standard is well accepted in the larger part of South-East Asia which is a prominent seismic zone. Since most of the structures in this region are commonly built without adhering to ductile provisions, usability of the damaged structure after any earthquake is of great importance. The existing building can be retrofitted using various techniques like Jacketing existing beams, columns, or joints, Use of Fibre Reinforced Cement, confinement of column by embedded composite grid, use of metal shear Panels (Steel and Aluminum), Use of steel fibre reinforced mortar, use of steel wire reinforced polymer, steel bracing, shape modification in column, external prestressing and post-tensioning existing beams, columns, or joints. So, in this paper, efforts are made to describe the different retrofitting techniques available and its suitability for particular conditions. Jacketing is excellent for column but it may not be too effective for beam or slab. Finally, selection criteria for retrofitting technique are briefly discussed.

Keywords: retrofitting, jacketing, ductile, confinement, prestressing

Article published in International Journal of Current  Engineering  and Technology, Vol.4,No.2 (April- 2014)