ASSESSMENT OF ACCELERATION FROM ISOSEISMALS 14 OF GREAT EARTHQUAKES

Abstract

Estimation of ground shaking due to potentially damaging earthquakes is required for earthquake resistant design of structures. Earthquake intensity is the qualitative measure of level of shaking, and isosiesmals are curves joining the equal intensity of the locality. These have been traditionally used by seismologists and earthquake engineers to study attenuation of ground motion with distance from the source and estimation of PGA of the earthquake. In the present study four great earthquakes namely Assam Earthquake of 1897, Kangra earthquake of 1905, Bibar Nepal earthquake of 1934 and Assam earthquake of 1950 is considered. The empirical relations given by Trifunac & Brady and Gutenberg & Richter have been used for estimating the strong ground motion. The maximum acceleration If computed is 1 .49g for the Assam earthquake of 1950.