SEISMIC EVALUATION OF UN-REINFORCED MASONARY HOSPITAL BUIDLING

Abstract

It is well known that masonry buildings suffer a great deal of damage during earthquakes, leading to significant loss of lives. Almost 75% of the fatalities, attributed to earthquake in last century, is caused by collapse of buildings of which the greatest portion (more than 70%) is due to collapse of masonry buildings. A majority of the tenements in India are Unreinforced Masonry (URM) buildings that are weak and vulnerable even under moderate earthquakes. On the other hand, a cursory glance through the literature on earthquake resistant structures reveals that a bulk of research efforts is on RC structures. Clearly there is a great need to expend more effort in understanding masonry buildings subjected to earthquake induced dynamic loads. The main aim of this thesis is to study the methodology given in various masonry structure related IS codes such as IS 1905-1987, IS 4326-1992 etc. for seismic evaluation of an more than 40 yrs old hospital building made of stone masonry. In hospital buildings more emphasis is given to non structural elements as they are part of important life line services therefore consideration of NSE is also incorporated. We have done firstly preliminary survey which include geometric properties of building as per ground and as per ledger, visual inspection and interaction with user and surrounding area. Then secondly we have gone for detailed seismic evaluation as per IS 1893 : 2002 & IS 1905 : 1987 for various failure mechanisms both local & global. Thirdly, we have suggested retrofitting measures as per various IS codes and also done cost comparison of retrofitting with respect to new construction. Lastly we have suggested some more measure keeping in view criticality of hospital.