SURVEY OF SOIL CONDITIONS OF RAILROAD EMBANKMENTS USING SEISMIC TOMOGRAPHY

This paper describes a seismic exploration method for investigating soil condition of Shinkansen railroad embankments. In this method, elastic waves are generated by human power, and all wave excitation points and receivers were set on the embankment slope surface. Seismic tomography was also presented with the exploration data for several railroad embankments. Since tomography results well agree with other methods, such as the down-hole PS logging conducted at the same place, this simple method is thought to be useful for the seismic survey especially in small-scale hilly topography. This method was then standardized by considering the local condition of railroad sites. Finally this method was applied to 4 sites of Shinkansen embankments, and some observations were mentioned concerning to the internal characteristics of the embankments constructed approximately 40 years ago.