Large-scale triaxial experiments on the static and dynamic behavior of an artificially cemented gravel material

This article presents the results of a set of 28 large-scale triaxial tests, including 12 consolidated-drained (CD) static tests and 16 consolidated-undrained (CU) dynamic tests, on an artificially cemented gravel. The strength, dilatancy, stiffness and damping behaviour of both the cemented and the uncemented specimens are compared. Cementation is found to have interrelated effects on increasing the peak strength, enhancing the dilative behaviour, increasing the static and dynamic stiffness, and reducing the damping ratio. Cementing the particles leads to a delayed but more evident dilative behaviour subsequent to an initial contraction, which is interpreted as the result of the existence of locked voids and the limited void-filling capacity of the cemented clusters. A cemented specimen generally yields before achieving its peak deviator strength, after which an increasing dilative behaviour is accompanied by strain softening. Cementation also increases the maximum shear modulus and reduces its dependence on the mean effective stress. Due to the bonds created near the contacts and their effect on restricting inter-particle sliding, the damping ratio of a cemented specimen is generally lower than that of an uncemented specimen, and the difference in the damping ratio becomes increasingly evident under an increasing shear strain amplitude.