ABSTRACT
Special attention has to be paid to the initial stress state. The sand can be placed by a pouring technique to obtain the K0-condition for sands, and a more or less constant density, which leads to similarity (Hettler 1981; Walz & Pulsfort 2009). If the sand is compacted layer by layer the horizontal stress may increase and reach the passive earth pressure up to a certain depth zp, see for example Broms (1971) and Hettler (2008). This may be of greater influence in smaller models and the scaling laws are not fullfilled. Also, the initial state has to be thoroughly analysed in cohesive soils. From a practical point of view, 1-g model tests are not appropriate in most cases. Even to produce a over-consolidated state, which fulfils the similarity requirements, means an enormous effort under 1-g conditions. Therefore the centrifuge tests may be the better choice in general.
