N-VALUE DISTRIBUTION PATTERN WITH DEPTH OF ALLUVIAL SOIL DEPOSITS

The paper focuses on two important inherent characteristics of N-values. The first being increase in N- value with depth caused by overburden pressure. It is proposed that this property of N-value may be approximately related to a root power law of confining pressure and this is specifically explained by a cavity theory in this paper. The second inherent characteristics is the change in pattern of N-value distribution with depth depending on geological age of alluvial soil deposits. Here an alluvial deposit in Busan is compared with the geological profile of Tokyo lowland area and Osaka bay. In these regions, upper parts of soft alluvial clay layer often has zero N-values indicating N-values of less than 1. This is generally followed by lower layers with large N-values. A comparative study of geological sediments shows a clear resemblance between lower parts of alluvial deposits in Busan and that of Tokyo lowland deposits of Nanagochi-so.