Experimental investigation has been carried out to study the effects due to isolation of foundations subjected to vertical vibration on the displacement amplitude. Tests were conducted on an embedded footing of contact area 45 x 45cm. with different embedments and some on the surface of natural ground. Three isolation barriers viz. air gap, saw dust and sand of various depths were used. From the results of the investigation it was found that an open trench (air gap) around the foundation reduces the displacement amplitude around the footing considerably to an extent of about 75%. Saw dust as a barrier, although not as good as air gap, performs better when compared to sand. The coefficient of attenuation is not a constant for a soil medium but varies with static and dynamic loads. The resonant frequency decreases and resonant amplitude increases by providing isolating barriers
