Alternative Method to Estimate the Seismic Demand of Piers and Wharves by Using 3D-Modal Pushover Analysis

Displacement-based design has become a common and accepted procedure for evaluating the inelastic performance of pile-supported wharves under seismic excitations. ASCE/CORPI 61-14 Seismic Design of Piers and Wharves presents several methods for assessing the displacement demand, including three-dimensional (3D) linear elastic response spectrum analysis, the substitute structure method, and nonlinear time history analysis. An alternative method known as 3D modal pushover analysis has been suggested to consider the effect of higher modes on the response of a wharf subjected simultaneously to two components of ground motion. An example of a designed wharf is used to demonstrate the applicability of 3D modal pushover analysis and quantify its accuracy against the outcomes obtained from standard methods.