Parametric Assessment of Equivalent Static Procedure Accounting for Foundation-Pinning Effects in Analysis of Piled Bridge Abutments Subject to Lateral Spreading

Foundation pinning is a critical consideration for design and analysis of bridge foundations subject to liquefaction-induced lateral spreading, particularly for bridges with a standard approach embankment of finite width. The simplified analysis procedure that has been generally adopted for this case makes consideration for foundation-pinning effects by considering the compatibility between the near-field soil and foundation displacements; however, there is a lack of guidance or evidence indicating the practical limitations of the simplified method. This paper discusses the results of a large parametric study carried out using three-dimensional (3D) finite-element models and simplified analysis models of corresponding site conditions. This study is designed to identify the range of conditions where the simplified method produces reasonable results and to determine the expected reduction in near-field displacements relative to those in the free field for different site geometries such that future applications of the simplified pile-pinning analysis procedure will have a benchmark for comparison.