INTRODUCTION

Occurrence of earthquake is no more a rare eventuality. India has witnessed several major earthquakes, involving substantial loss of lives. To name a few, a major earthquake (Richter scale 8.5) occurred in Assam in 1897 wherein the reported death toll was 1500. It was repeated at the same place in 1950 with similar number of reported deaths. Similarly in 1934 major earthquake (Richter scale 8.4) occurred in Bihar-Nepal area claiming 14,000 lives. It was repeated in 1988 claiming about 1000 lives. The most recent major earthquake (Richter scale 8.0) in Bhuj claimed over 20,000 lives. By and far, major earthquakes have been observed to repeat in about 50 years in high earthquake prone areas.

Comparatively, a larger number of bridges have been affected by seismic activities in America and Japan than those in India. Latur earthquake in 1993 did wake up the authorities to survey the bridges in Maharashtra area, retrofit and rehabilitate those bridges. Golden Gate Suspension Bridge, San Fransisco has been another example of Earthquake Retrofitting. Technique of retrofitting is not unique or predefined. It has to be decided on case to case basis, depending upon the prevailing circumstances.

To view the whole Article click on "View PDF" button provided below :