Experiences of soil mechanics show that different soils can have practically the same or approximately same technical properties. A similarity of soils from point of view of bearing capacity/stability (ULS) analyses depends on more parameters and their combinations and due to it a comparison is more complex. It appears a criterion of soil suitability to the geotechnical construction should be useful and the problem may be named “constructive similarity”. Experience exploitation is important part of a correct and reliable design. In geotechnics, very different random material properties make problem of the experience exploitation much more difficult. The experience exploitation needs a clinical scale for constructive evaluation of a soil similarity and suitability. That general (independent on the structure type) scales are similarity characteristics k_π and k_λ. The Paper concerns with an analysis of the soil similarity according to constructive characteristics k_π and k_λ exploiting the last version of the soil DATABASE ITAM 2013. The analysis is performed from the point of view of reliability of soils for geotechnical constructions and applies especially constructive characteristics k_λ. Reliability of designs according to the standard EN 1997-1, AP 1/2, is analysed and a conclusion is recommended.

Keywords: Soil similarity, Similarity characteristics, Reliability, Soil property database, Soil group variability, Soil homogeneity, Standard design.