NORMALIZED DYNAMIC UNDRAINED STRENGTH OF SANDS SUBJECTED TO CYCLIC AND RANDOM LOADING

Normalized cyclic undrained triaxial stress-strain relationships of undisturbed sandy specimens are discussed in this paper. Cyclic undrained triaxial strengths defined by axial strain amplitudes and developments of excess pore water pressure are analyzed. A simplified equation for evaluating cyclic undrained triaxial strength of sands is derived. Based on the empirical normalized strength equation, a relationship between strength for a uniform cyclic loading and that for a random cyclic loading is obtained. A simplified method for evaluating an equivalent uniform loading strength for a random loading is proposed using a strength curve through uniform cyclic loading tests.