Consolidation Settlement of Bridge Approach Foundation

Abstract

Excessive settlement of bridge‐approach pavements creates problems for both road users and transportation agencies responsible for road maintenance. An important contributing factor to this settlement is the consolidation of foundation soil. A procedure based on the nonlinear finite‐element method (FEM), including infinite elements, is developed to analyze the consolidation settlement of embankment foundation at the bridge approach. Biot's theory of three‐dimensional consolidation, as proposed by Sandhu and Wilson, is used in the development. Nonlinear behavior of the soil skeleton is represented by the modified Cam‐clay model. A plane‐strain infinite‐element algorithm is developed. The semi‐infinite domain is divided into two regions. The near field is discretized by using the eight‐noded isoparametric elements, while the far field is discretized by using the infinite elements developed. The interpolation functions for the infinite element are chosen based on the far‐field behavior of a homogeneous porous elastic half plane. The analysis procedure is applied to study the time‐settlement history and pore‐pressure dissipation characteristics of a bridge‐approach site in Oklahoma.