Subdivision of So-called Alluvial Deposits by Soil Engineering Properties and Application to Database System of Ground Geology

Abstract

In Niigata Plain, so-called Alluvial deposits are subdivided into two formations, namely the Shirone Formation ( Late Pleistocene ) and the Holocene Higashi-Niigata Formation ( Kurotori Formation ) in ascending order. The relationships between the geological age and the soil enginnering properties of so-called Alluvial deposits are investigated. As a results, the relation between void ratio (e) and liquid limit (wL) of silty and clayey deposits shows significant difference ( Fig. 6 ) and following discriminant is obtained.
Z=1.846e-4.048log₁₀ WL+4.599
Comparison of the results of subdivision of so-called Alluvial deposits by this discrimant with the results by stratigraphical method shows more than 80% of them corresponded well together. And the application of this discriminant to Database system of ground geology is discussed.