Simplified seismic analysis of soil–well–pier system for bridges

Seismic analysis of soil–well–pier system was carried out using three different approaches to evaluate their comparative performance and associated complexities. These approaches were (a) two-dimensional nonlinear (2D-NL), (b) two-dimensional equivalent-linear (2D-EqL), and (c) one-dimensional spring–dashpot (1D). Soil was modeled as 2D plane-strain elements in the 2D-NL and 2D-EqL approaches, and as springs and dashpots in the 1D approach. Nonlinear behavior of soil was captured rigorously in the 2D-NL approach and approximately in the remaining two approaches. Results of the two approximate analyses (i.e., 2D-EqL and 1D) were compared with those of the 2D-NL analysis with the objective to assess suitability of approximate analysis for practical purposes. In the 1D approach, several combinations of Novak's and Veletsos' springs were used to come up with a simplified 1D model using three types of spring–dashpots. The proposed model estimates the displacement and force resultants relatively better than the other 1D models available in literature.

► Performed seismic analysis of soil–well–pier system using three approaches requiring different levels of modeling efforts.
► Evaluated their comparative performance and associated complexities.
► Proposed 1D spring–dashpot model using three types of spring–dashpots for analyzing well foundations.