Static Piezocone Penetration(SPP) tests were carried out at seven Japanese coastal sites where thick alluvial clay is deposited. Comparing values obtained from
the laboratory tests, cone factors such as Nkt and Bq are derived. The main conclusions are as follows;
1) Using Levadoux and Baligh's theoritical consolidation curve, coefficients of consolidation, cυ are calculated from the dissipation test of the excess pore pressure. The calculated cυ is 20 - 50 times as large as that in normally consolidated state from the laboratory tests.
2) The penetration resistance factor, Nkt is not dependent on plasticity index, PI, and its range is between 8 and 16.
3) Characteristics of the pore pressure parameter during the penetration of SPP can be expressed by Bq factor, and its value is between 0.6 and 0.8.