The thesis deals with the stiffness of soils at small strains. The analysis of excavation supported by the
retaining diaphragm wall, for which horizontal movements with inclinometers were measured during
and after construction, shows that small strain stiffness and its nonlinear dependancy on the strain
amplitude should be properly taken into account to get reliable predictions of displacements.
Finite element numerical analyses with computer program Plaxis were carried out taking into account
two different material models: The nonlinear elasto-plastic model with isotropic hardening (Hardening
Soil Model – HS model) and nonlinear elasto-plastic model with isotropic hardening and small strain
stiffness (Hardening Soil Small Model – HSSMALL Model). The analyses were limited to the
comparisson of bending moments and horizontal displacement of the diaphragm wall. The results of
analyses, that consider HS model, show, that the bending moments and horizontal displacements are
higher compared to inclinometer measured horizontal displacements. The HSSMALL model gives
much better predictions as compared to the measured values of displcemants and therefore is more
convenient for the analyses of such constructions.