Special Features of Creep of Clayey Soils

The problem of settlement predictions in clays involves the solution of complex engineering challenges associated with the determination of many experimental parameters (modulus of deformation, lateral expansion ratio, coefficients of permeability and consolidation, as well as rheological characteristics). The full analysis of ground behavior during consolidation and creep of the solid soil particles at the time of the construction and operation is only possible if the site investigation and laboratory results arc reliable. In this paper the authors present the results of the long-term settlement observations (over 50 years) of large industrial facilities of Karaganda Metallurgical Complex and the soil properties of these sites based on the thorough site investigation program. The underlying soils have sufficient bearing capacity, relatively high values of density and low void ratios. The creep deformations at the constant loads in the saturated state exhibited gradually decreasing character. The actual settlements of the structures and the maximum allowable settlements (by the building codes) are compared. The conclusion is made on the need to amend the recognized formula given by the building codes for the ground analysis by the second group of limiting states.