Interaction of Beams with Consolidating Nonlinear Poroelastic Layered Soil

Abstract

A computationally efficient semianalytical framework for obtaining the consolidation settlement of flexible foundations such as beams and strip footings resting on nonlinear, saturated, poroelastic, and multilayered continua (soil) is developed. Two-dimensional (2D) plane strain is assumed, and Biot’s consolidation theory is used in the analysis. The differential equations governing the displacements and excess pore pressure dissipation of the beam-soil system are developed using the variational principles of mechanics in which the soil is modeled as a simplified continuum and the foundation is modeled as an Euler-Bernoulli beam. The developed differential equations are coupled and are solved following a unique iterative algorithm using one-dimensional (1D) finite-element analysis. The numerical solution is less expensive than conventional 2D numerical methods. A distinct feature of the developed framework is that the effect of soil stress-strain nonlinearity is considered in the calculation of the consolidation settlement, which is usually not considered in Terzaghi’s and Biot’s consolidation theories. It is observed that soil nonlinearity and foundation flexibility can significantly impact the foundation settlement and consolidation rate. The developed framework provides a fast, easy-to-use, and accurate method for estimating the consolidation settlement of flexible shallow foundations.