International Journal of Geotechnical Earthquake Engineering, 2(1), 83-97, January-June, 2011 83 Copyright © 2011, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. Keywords: Ash Ponds, Seismic Hazards, Shear Wave Velocity, Site Characterization, Soils INTRODUCTION Thermal power plants are the major sources of ash generation in India. Since low ash high- grade coal (Lignite) is reserved for metallurgi- Dynamic Characterization of Settled Pond Ash Using Measured Shear Wave Velocity (V s ) and SPT-N Values: Correlation Between V s & N Ravi Sankar Jakka, Indian Institute of Science, Bangalore, India B. Janaki Ramaiah, Indian Institute of Technology, Delhi, India G. V. Ramana, Indian Institute of Technology, Delhi, India ABSTRACT Reclamation of abandoned ash ponds for the construction of engineered facilities like gas based power plants, light weight structures, or parking lots often requires site specifc response analysis to assess associated seismic hazards in seismically active areas. This requires dynamic site characterization of the ash ponds. In the present study, shear wave velocity measurements (V s ) from SASW technique are used for in-situ dynamic site characterization of the ash ponds. Measuring V s on the ash ponds is diffcult compared to the soils, as the ash deposited in the ponds is often in a very loose state and in swampy conditions. Shear wave velocities measured at three hydraulically deposited ash ponds in Delhi are presented. An empirical correlation be- tween SPT (N) value and measured V s is also developed. The authors observe that the developed correlation between N and V s is signifcantly different than those reported for the soils, which signifes the importance of dynamic characterization of ash ponds using shear wave measurements rather than using empirical relations developed for soils. cal and other industries, thermal power plants have no choice but to use low-grade coal (sub- bituminous and bituminous) having ash content ranging from 35% to 50%. Current existing 85 thermal power plants in India produces about 112 million tons of coal ash annually where as its utilization is only about 42 million tons (37.5%) DOI: 10.4018/jgee.2011010106