Determining Seismic Bearing Capacity of Footings Embedded in Cohesive Soil Slopes Using Multivariate Adaptive Regression Splines
Van Qui Lai, Fengwen Lai, Dayu Yang, Jim Shiau, Wittawat Yodsomjai, Suraparb Keawsawasvong
Abstract
Abstract Seismic bearing capacity of strip footings in cohesive soil slopes considering various embedded depths is investigated in this study. Novel solutions using pseudo-static method and finite element limit analysis (FELA) with upper bound (LB) and lower bound (LB) theorems are presented. The influences of footing depth, slope angle, slope height, undrained shear strength and pseudo-static acceleration on bearing capacity and failure mechanisms are examined using dimensionless parameters. With the comprehensive numerical results, the multivariate adaptive regression splines (MARS) model is then utilized to simulate the sensitivity of all dimensionless input parameters (i.e., the normalized depth of footing D/B, the normalized slope height H/B , the normalized distance from top slope to edge of the footing L/B , slope angle β , the strength ratio c u /γB , and the pseudo-static acceleration factor, k h ). The degree of influence of each design parameter is produced, and an empirical equation for the dimensionless output parameter (i.e., bearing capacity factor N c ) is proposed. The study results are accessible in the design charts, tables, empirical equation for design practitioners.