An examination of the work of Special Section IV of the Congress indicates that Soviet and foreign specialists are paying considerable attention to problems of the strength of foundations and stability of rigid concrete and reinforced-concrete retaining structures. It should be stated that the approach to the solution of the indicated problems is rather similar for specialists of different countries. However, as a rule, higher indices of the shear resistance of soils, especially of rock foundations of hydraulic structures, are used for designing retaining structures in the USSR. The correct selection of the design characteristics of the shear resistance of foundation soils with consideration of the characteristics of their natural occurrence remains the main problem of stability calculations. Therefore, along with laboratory investigations, much attention should be given to large-scale field experiments (loading and shearing of plates) for determining the deformation and strength properties of soils, which permit determining the integral design characteristics of the soils in situ, especially for less studied foundations composed of cohesive soils. It should also be noted that the use of a sufficiently simple calculation apparatus and considerable attention to a detailed study of the physical and mechanical properties of soils are characteristic for leading foreign specialists. From this standpoint a detailed study of the geologic structure of foundations and physical and mechanical properties of foundation soils in depth with the use of modem field methods-pressiometers, penetration, vanes, etc., should be developed further.