This　study　presents　a　hybrid　framework　to　predict　stability　solutions　of　buried　structures　under　active　trapdoor　conditions　in　natural　clays　with　anisotropy　and　heterogeneity　by　combining　physics-based　and　data-driven　modeling.Finite-element　limit　analysis(FELA)with　a　newly　developed　anisotropic　un-drained　shear(AUS)failure　criterion　is　used　to　identify　the　underlying　active　failure　mechanisms　as　well　as　to　develop　a　numerical(physics-based)database　of　stability　numbers　for　both　planar　and　circular　trapdoors.Practical　considerations　are　given　for　natural　clays　to　three　linearly　increasing　shear　strengths　in　compression,extension,and　direct　simple　shear　in　the　AUS　material　model.The　obtained　numerical　solutions　are　compared　and　validated　with　published　solutions　in　the　literature.A　multivariate　adaptive　regression　splines(MARS)algorithm　is　further　utilized　to　learn　the　numerical　solutions　to　act　as　fast　FELA　data-driven　surrogates　for　stability　evaluation.The　current　MARS-based　modeling　provides　both　relative　importance　index　and　accurate　design　equations　that　can　be　used　with　confidence　by　practitioners.