Abstract
This paper compares four methods that predict jackup rig spudcan penetration with measured load-penetration records at thirteen Gulf of Mexico locations. Predicted load-penetration curves, for the four methods, are determined using site-specfic geotechnical information for normally to slightly over-consolidated clay soil profiles. The four methods include two based on SNAME (2002) recommendations, using bearing capacity formulations as proposed by Skempton (1951) and Hansen (1970), a method recommended by Houlsby & Martin (2003), and a method recommended by Hossain et al. (2006). Detailed spudcan geometries and dimensions from the seven different types of jackup rigs installed at the thirteen locations are also provided. Spudcan diameters of the seven jackup rigs vary from 11.0 to 20.1 meters and spudcan bearing pressures range from 162.8 to 507.4 kPa. Interpreted soil parameters are presented for all thirteen sites. Boring logs, illustrating the interpretation of parameters from the measured soil properties are presented for two of these locations. The logs present the results of standard laboratory tests typically performed for Gulf of Mexico site investigations: undisturbed undrained shear strength measurements from Torvane, miniature vane, pocket penetrometer and unconsolidated-undrained (UU) triaxial tests; remolded shear strength from miniature vane and UU triaxial tests; submerged unit weights (derived from measured bulk wet unit weight); water content; and Atterberg limits. Theoretical submerged unit weight values, used as an aid in parameter selection, are also plotted on the boring logs.
