Influence of Duration of tests at Constant Rate of Strain on Measured “Drained” Strength

Synopsis Theory shows that a fully drained condition is impossible to attain in a laboratory “drained” test run at a constant rate of strain. However, expressions which have been derived in this paper enable an estimate to be made of the duration of the test necessary to ensure a certain closeness of approximation to the fully drained condition. The results of a number of drained triaxial and shear-box tests on three clays—eked out at various rates of strain are shown to confirm, in a general way, the predictions of the theory. La theorie demontre l'impossibilite d'obtenir une condition completement drainee, au cours d'un essai de drainage effecte dans le laboratoire a un taux constant de charge. Cependant, lee expressions deivees dans cette etude permettent d'etablir la duree approximative de l'essai necessaire pour assurer une certaine exactitude d'approximation a la condition completement drainee. Les resultats d'un certain nombre d'essak triaxiaux et de boite de cisaillement avec drainage faits sur tr...