Comparative study of static and dynamic penetration tests currently in use in Japan

This chapter summarizes the observed field relations of the above-mentioned six methods of penetration testing in Japan. In addition to the above-mentioned methods, the portable cone penetration test and dynamic cone penetration test are widely used in investigations. The relation between N values and qc values on the whole show large scattering. The values contained therein are the result of a comparative study conducted by the Japan Highway Public Corporation during construction of the Meishin Expressway between Kobe and Nagoya. As can be seen in this figure, Nd values of the RTRI-DPT are somewhat larger than the N values of the SPT as a result of skin friction against the single-rod penetration tested. The relation observed above is important because it gives factual evidence for rational conversion between N values and qc values in alluvial soils and permits the modification of nS/D according to the grain-size distribution of a soil.