2025 Volume 81 Issue 13 Article ID: 24-13473
In this study, the influence of the trajectory characteristics of bi-directional horizontal seismic input motions on the liquefaction and nonlinear seismic response of sandy soils was evaluated using seismic response analyses with various types of spectrum-compatible waves. The seismic input motion for liquefaction was assessed based on its bi-directional energy spectrum and cumulative displacement. The results of the ground seismic response analysis indicated that the excess pore water pressure ratio was higher for bidirectional inputs than for uni-directional inputs. This confirms the significant influence of the trajectory characteristics of bi-directional horizontal seismic ground motions on sandy soils. Additionally, the calculated bi-directional energy spectrum and cumulative displacement were larger for bi-directional inputs compared to uni-directional inputs, which was consistent with the excess pore water pressure ratio results. Consequently, it is recommended that the seismic input motion for liquefaction should be evaluated in terms of its energy spectrum.