Title : SEISMIC DAMAGE AND STRENGTHENING OF BUDDHIST MONASTERIES IN SIKKIM INDIA
Authors : Arun Menon and C.V.R. Murty
Publication : 13th – 16th February 2013
Volume :
Pages : 10-Jan
Price : 250
Abstract : Sikkim, a Himalayan state in north-east India, has a number of Buddhist monasteries, many of which date back to 16th century AD. These are masonry structures, constructed with random rubble masonry (RRM) walls, timber floors and roofs. Some have masonry walls with timber framework. Monasteries constructed in recent decades are reinforced concrete (RC) structures with infill masonry. Structural repairs in recent years have led to introduction of RC elements in these historical structures, with most interventions being non-engineered. Extensive damage to historical monasteries was observed in the Mw 6.9 Sikkim earthquake of 18th September 2011, with partial to total collapse in several monasteries. Some monasteries were retrofitted after an earthquake in 2006, but suffered damage during the current event too. Typical seismic damage observed includes: out-of-plane bulging or collapse of RRM walls, sliding of timber roof relative to walls, out-of-plane collapse of corners of RRM walls and shear failure of RC columns. Vulnerable historical masonry structures in seismically active regions, such as Sikkim, require a comprehensive programme starting with a concerted scientific effort to document structural systems, investigate their seismic behaviour and propose strengthening schemes. Without this, a small but certain fraction of these monasteries, a rich heritage of Buddhist Sikkim will be repeatedly lost in future earthquakes. The paper presents an investigation on these lines evaluating methods for seismic strengthening.