All existing closed-form solutions for sheet-pile analysis and design are based on the assumption of material homogeneity below the dredge line. Unfortunately, the composition of natural deposits is often quite complex, and it is common for a cohesive foundation soil to possess an undrained shear strength that varies continuously, or in a stepwise fashion, with depth. Thus, a closed-form soution is derived to permit total stress (phi = 0) analyses of cantilever sheetpiling in such inhomogeneous foundation profiles. The governing equations associated with multiple foundation strata are found to be similar in form to those associated with a single foundation layer. A computer program is developed to solve the generalized equations for the required piling penetration depth and the maximum bending moment. The new analytical technique is verified by performing manual equilibrium checks on a variety of computer-generated solutions. The analytical technique is also used to establish appropriate piling penetration depths for several inhomogeneous foundation profiles that have been described in prior geotechnical literature.
