Assistant professor, Faculty of engineeringMember of ASTM, American University of Beirut, New York, N.Y.
A mechanistic model for strength and fatigue of cement-treated soils is developed using the Griffith failure theory for the purpose of understanding the structural behavior of cement-treated bases in pavements. Failure under static loads is assumed to occur when the tensile stress at the tip of the most critically oriented flaw reaches a value characteristic of the material. This static failure model is used to study fatigue behavior under repeated stresses. Results of repeatedload triaxial tests on a clayey gravel soil cement are used to define fatigue failure criteria for cement-treated soils. The analytical fatigue model developed is used to derive a cumulative damage hypothesis. According to this hypothesis, fatigue behavior under compound loading depends on the sequence and magnitude of applied loads and the curing age of the cement-treated material. The hypothesis also suggests that Miner's rule could lead to unconservative predictions of fatigue life under random loading conditions.
Paper ID: GTJ10775J