DETERMINATION OF DYNAMIC MODULUS OF ELASTICITY OF SOIL USING ULTRASONIC TECHNIQUE

Abstract

Dynamic modulus of elasticity of soil is one of the important parameters for the design of foundations subjected to dynamic loading. Ultrasonic Test is the quickest and non-destructive method for determining soil parameters appropriate for dynamic analysis at strain ranges smaller than the laboratory tests presently available. In this method dynamic Young's modulus or dynamic shear modulus of soil is determined by measuring the velocity of ultrasonic longitudinal or shear wave transmitted through the material. In the present study, dynamic modulus of elasticity (Ed) of CL and CL-ML soil have been determined by measuring the velocity of ultrasonic longitudinal wave transmitted through the soil sample. Values of dynamic elastic modulus of CL soil have been determined at three different dry unit weights (1.5 t/m3, 1.6 t/m3 and 1.7 t/m3) varying the degrees of saturation from 20% to 80% at the increment of 20%. Wheareas for CL-ML soil, dynamic elastic modulus were determined at dry unit weight 1.7 t/m3, 1.8 t/m3 and 1.9 t/m3 varying the degree of saturation from 20% to 80% at the increament of 20%. The effects of increasing dry unit weight and degree of saturation on dynamic elastic modulus values of both the soils were studied. Penetration resistances of both the soils were measured at same conditions mentioned above. Unconfined compression test was done on CL soil as supporting