Drained Axisymmetric Loading of Reinforced Clay

Abstract

To investigate the behavior of reinforced clay, drained triaxial compression tests were performed on kaolin clay reinforced with horizontal discs of sintered porous plastic. The results of two series of tests are presented—on involving the use of multi‐reinforced samples and the other using unit cells of clay of various heights. In both cases it was found that decreasing the spacing between the horizontal layers of reinforcement increased both the drained shear strength and the secant deformation modulus of the reinforced sample. The results of a radiographic investigation are also presented, which indicate the mechanism of the strength enhancement to be one of radial strain control, arising from shear stresses mobilized on the soil‐reinforcement interface. The experimental results are compared with a theoretical model, the basis for which is that the radial shear stresses lead to an enhanced minor principal stress, and hence, enhanced strength. Upper and lower bounds are defined, within which the experimental results are generally found to fall.