Abstrakt
In situ effective stresses, expressed usually by the at rest coefficient K0, influence the mechanical behaviour and thus any geotechnical analysis. In normally consolidated soils K0 can be computed according to the Jáky formula.
For overconsolidated clays however neither a general formula nor a general experimental procedure are available. The paper summarizes briefly the available methods and then presents some methods in more detail.
First the use of flat dilatometer is discussed. Further, K0 is determined by back analysing the convergence of a circular test gallery.
Finite element analysis using the hypoplastic constitutive model to represent the clay behaviour is adopted in the analyses.