DETERMINNATION OF DYNAMIC SHEAR MODULUS BY CROSS BORE HOLE TEST

Abstract

The analysis of many foundation and soil structure interaction problem requires an accurate estimation of Insitu values of elastic moduli for foundation material. Seismic techniques offer one logical approach, to the solution of the problem of detection of cavities, open fractures, zones of weakness or other discontinuities. The seismic technique used for determination of dynamic shear modulus in present study is cross bore hole test. The cross bore hole method is one of the most popular and reliable among seismic methods as in this the seismic properties of the underlying materials between any two points of a test site can be accurately determined and the varitations of these properties with depth can be obtained. A number of investigators have over the years tried to evolve relationship for the assessment of shear wave velocities in soil and rock media based on parameters like S.P.T. Value, soil type depth of assessment and geological age of deposit. In our present study we have tried to evolve an empirical relation for predicting shear wave velocity for Roorkee soil ( at Department ) and dynamic shear modulus considering this shear wave velocity compared with dynamics shear modulus considering the shear wave velocity those obtained by cross bore hole test