Theoretical Analysis and Finite-Element Simulation for Nonlinear Poroelastic Behavior of Cylinder Expansion in Infinite Media under Transient Pore-Fluid Flow Conditions

Abstract

The response of infinite cylinder expanding in a poroelastic medium is investigated analytically in this paper on the basis of Biot's consolidation theory. The approach is based on the local equivalence between the response of a perfectly plastic behavior to the monotonic loading process and an appropriate fictitious nonlinear poroelastic behavior. A simplified framework was adopted for the diffusion equation to derive a closed-form expression for pore-fluid pressure distribution, whereas stresses and displacements were computed numerically. The related theoretical results are discretized and critically compared to finite-element solution, showing good agreement in terms of radial stresses and normalized pore pressure distributions. For in situ testing, interpretation, and foundation design purposes, results interpreted in the space of normalized velocity (V) versus degree of drainage (U) demonstrate the model capability of capturing the transitions from drainage to partially drained and undrained soil regimes.