TENSILE AND COMPRESSIVE STRENGTH OF CLAYS FOR ASSESSING CRACKING CONDITIONS IN DAMS.

In engineering practice of earth-dam construction an assessment of cracking conditions unites the problems: of checking the possibility of occurrence of cracks, studying the behavior of the zone of discontinuity, and developing measures and designs. The known methods of checking a soil mass for cracking give quite approximate solutions, usually with a considerable overestimation of the zones of possible discontinuity. The main cause of imperfection of these methods is incompleteness of the data on the behavior of soils under conditions of loading by tensile and compressive stresses. A number of works are devoted to this problem, in which strength tests are limited to bending, uniaxial tension or stabilometer-type tests, which do not permit investigating the complete picture of soil behavior as a function of the loading conditions. This resulted in practically all cases that the conditions of limit (plastic) equilibrium for the region of soil tension are formulated on the basis of simplified theoretical constructions. Data generalizing the first stage of investigations of methods of determining the tensile and shear strength of soils under conditions of a low loading level performed for an engineering assessment of cracking conditions are presented.