SEISMIC REHABILITATION OF BUILDINGS AFFECTED DURING EARTHQUAKES

SEISMIC REHABILITATION OF BUILDINGS AFFECTED DURING EARTHQUAKES

ABSTRACT

Of many types of natural disasters, an earthquake is the most deadly catastrophe. Several mid-rise and few high rise buildings collapsed during the earthquakes in Ahmedabad in 2001 and in POK in 2005. Most of the structural failures are due to not taking into account the earthquake resistant features of construction. It is a well-established fact that the buildings incorporating earthquake resistant features cost about 2 to 5 percent more than the one without it and the repair work costs about 4 to 6 times the initial cost. Despite of this fact, buildings are not constructed with earthquake resistant features. The structural safety is of great concern in earthquakes. The issues of structural safety immediately after an earthquake are:
(i) rapid evaluation of condition of damaged structures,
(ii) identification of the structures that can be repaired, restored and retrofitted,
(iii) earthquake safety of existing structure.
Seismic rehabilitation is a comprehensive term used to include concepts of ‘repair’, ‘upgrading’ and ‘retrofitting’ that reduce seismic vulnerability of buildings. It calls for three kinds of improvements in the structure i.e., Repair in which only visual and cosmetic modifications are made, Restore structural repairs like rebuilding of cracked wall etc. and Retrofit structures such as addition of shear walls etc. The present paper deals with the various issues relates to seismic rehabilitation and its implementation.