Cyclic Loading of Sands, Silts and Clays

The purpose of this paper is to illustrate that the response of saturated soils (sands, silts and clays) to cyclic loading may be describable with one behavioral model. The behavioral model is based on critical void ratio and critical state concepts - i.e., this use of void ratio and effective stresses as key parameters to define the state of the soil and therefore its response to cyclic loading. Using the model described herein for response of soils to cyclic loading it is possible to understand: Strength reduction in sands (i.e., liquefaction) and in fine grained soils in the contractive state; Levels of cycled stress which can be continued without significant strain; maximum levels of pore water pressure developed under cylic loading of contractive sands, silts and clays; the absence of strength reduction due to cyclic loading of undrained dilative soils; and, volume changes during and subsequent to cyclic loading. Test results from a variety of natural sands, silts and clays are used to illustrate the behavioral model. /Author/