Shear strength variability of sandy and fine-grained soils

The soil and rock variability is a constitutive characteristics of geotechnical materials and it is important to know utmost on it. This knowledge is necessary for a regular and solid calibration both the Limit State Design theory and, of course designs according to EC 7-1 (see Ref.). The most important in-put data for the Ultimate Limit State Design are data of shear strength and unit weight. The mentioned reasons led to the establishment of a database of physical properties of soils in solid and reliable laboratories tested and to concentrating on shear strength and unit weight. The database is supported continuously a number of years at the Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences. The paper brings summed database data and deals with the statistical analysis of the single soil groups taking use of the database to date. The analysis could provide a better quantitative view at a possible influence of soil variability in geomechanics and in geotechnical design.