The use of dilatometer test for the determination of undrained shear strength in organic soils The use of dilatometer test for the determination of undrained shear strength in organic soils. In engineering practice the empirical correlations or charts are often use to determine soil properties for design calculations. The DMT tests results are analysed on the basis of the empirical formulas proposed by Marchetti (1980). In this paper the new chart to determine the τfu of organic mud was proposed. The chart presents the relationships between dilatometer readings (p0 - u0), (p1 - u0), σ'v0 and τfu. The chart will be helpful in geotechnical design of embankments constructed on organic subsoil.