Soil-Nailed Wall Under Piled Bridge Abutment: Simulation and Guidelines

Abstract

A three-dimensional (3D) nonlinear finite-element analysis is used to study the behavior of soil-nailed walls constructed under a bridge abutment built on piles. The numerical model simulates the piles and the nails with beam elements, the abutment and the pile cap with solid 3D brick elastic elements. The soil model used is a modified hyperbolic model with unloading hysteresis. The complete sequence of construction is simulated including the excavation of the embankment slope under the bridge in front of the abutment and the placement of the nails. The numerical model is calibrated against an instrumented case history. Then a parametric study is conducted. The results give information on the effect of the excavation and nail placement on the following: axial load and bending moment in the piles and load in the nails and wall deflections. The results are used to suggest design guidelines.