Research of undrained shear strength of till fine soils (moraine)

The undrained soil strength is specific to fine soils or to sands with a lot of fines. It is very important characteristic and the evaluation of accurate value is significant step. The undrained soil shear strength can be estimated directly in laboratory and indirectly in field using in-situ methods. The values of undrained shear strength estimated with different methods usually are different, sometimes very much. In geotechnical practice a lot of empirical equations are used to calculate undrained shear strength (cu), however it corrects only in specific conditions and can’t be used universally. The empirical factor (Nk), which is used in mentioned equations, varies in wide range. It depends on many factors. The research of glacial genesis fine soils (various moraines) is complicated because it specific grain size distributions and genesis. In this article we will study relation between different laboratory and field methods to estimate of undrained shear strength (cu) of till soils. For these purposes we will used upper Pleistocene, upper Nemunas formation till fine soils.