Abstract
A new type of disk transducer with the size of 80 mm diameter has been developed successfully by assembling 4 numbers of p-type piezo ceramic element and 4 numbers of s-type piezo ceramic element, in order to carry out the elastic wave study of small to large g rain size geomaterials on single apparatus. Properties of fine to medium sand measured by proposed disk transducer method were compared with previous research and the stiffness found to be fallen in similar range within allowable scatters. It was also confirmed that the large disk transducer can be applicable to gravel having mean diameter of 12mm.
