Cyclic Stress-Strain History and Shear Characteristics of Clay

Effects of some factors on the excess pore pressure are clarified, followed by an examination of the reliability of cyclic pore pressure measurement, the normalization of stresses, and the failure due to cyclic loading of clays. An equation of the residual excess pore pressure, represented as a function of both the maximum cyclic shear strain and the overconsolidation ratio, is deduced. An overconsolidated state due to the cyclic stress-strain history is similar in strength to one due to the ordinary overconsolidation history. In spite of the temporary loss in strength and deformation modulus immediately after cyclic loading, the dissipation of pore pressures leads to higher strength and deformation modulus than the initial ones before cyclic loading. It is implied that cyclic stress-strain history can be one of the factors causing natural ground to become lightly overconsolidated.