Table Japan 1
Tc
and Soil classification
| Soil type | Ground characteristics | Tc |
| Hard soil | Ground consisting of rock, hard sandy gravel, etc. classified as Tertiary or older. | 0.4 |
| Medium soil | Other than hard type or soft one. | 0.6 |
| Soft soil | Alluvium consisting of soft delta deposits, topsoil, mud, or the like (including fills, if any), whose depth is 30 meters or more, land obtained by reclamation of a marsh, muddy sea bottom, etc., where the depth of the reclaimed ground is 3 meters or more and where 30 years have not yet elapsed since the time of reclamation. | 0.8 |