Reduction of footprint problems on spudcan in sand with infilling method

Abstract

This paper presents experimental data associated with the reactions on the spudcan during the reinstallation of a jack-up foundation near a footprint with and without infilling. All experiments mentioned in this paper were conducted in a 1g model spudcan testing facility. Loose Ottawa sand was used as the seabed and infilling material, and the diameter D of the conical model spudcan was 200 mm. Based on the experimental data, it was found that, with the infilling of the footprint crater, a flat bearing surface was generated on the seabed; therefore, the hazardous stamp-on-void situation was prevented. This was the major contribution of the infilling method. At the small reinstallation depth of 0.05D, between the small offsets 0 and 0.25D, the stamp-on-void condition was eliminated by infilling, and the infilling effect was especially significant. At the large offset 2.0D, since the reinstallation was conducted far from the influence of the first penetration and the footprint crater, the infilling effect nearly vanished. The effect of infilling decreased with increasing reinstallation depth and increasing offset distance.