The sudden increase of sliding displacement of base when losing stability and failing was well explained by analyzing the stability of trip foundation on clay considering lateral force and bending moment effect with cusp-catastrophe model theory. The effect of lateral force and bending moment
the density of soil and the depth of foundation
high order of displacement
the variation of displacement field with lateral force
etc. on the base’s stability and its catastrophe character was discussed. The analysis shows that when parameters go across bifurcation set
the foundation will get unstable and failed due to its sudden sliding change in a jumping style; when the variation of displacement field with lateral force is neglected