<p>The feasibility of constructing shallow foundations on saturated sands remains uncertain. Seismic design standards simply stipulate that geotechnical investigations for a shallow foundation on such soils shall be conducted to mitigate the effects of the liquefaction hazard. This study investigates the seismic behavior of strip foundations on typical two-layered soil profiles—a natural loose sand layer supported by a dense sand layer. Coupled nonlinear dynamic analyses have been conducted to calculate response parameters, including seismic settlement, the acceleration response on the ground surface, and excess pore pressure beneath strip foundations. A novel liquefaction potential index (<i>LPI</i>_footing), based on excess pore pressure ratios across a given region of soil mass beneath footings is introduced to classify liquefaction severity into three distinct levels: minor, moderate, and severe. To validate the proposed <i>LPI</i>_footing, the foundation settlement is evaluated for the different liquefaction potential classes. A classification tree model has been grown to predict liquefaction susceptibility, utilizing various input variables, including earthquake intensity on the ground surface, foundation pressure, sand permeability, and top layer thickness. Moreover, a nonlinear regression function has been established to map <i>LPI</i>_footing in relation to these input predictors. The models have been constructed using a substantial dataset comprising 13,824 excess pore pressure ratio time histories. The performance of the developed models has been examined using various methods, including the 10-fold cross-validation method. The predictive capability of the tree also has been validated through existing experimental studies. The results indicate that the classification tree is not only interpretable but also highly predictive, with a testing accuracy level of 78.1%. The decision tree provides valuable insights for engineers assessing liquefaction potential beneath strip foundations.</p>