Study on vertical bearing capacity of solid and perforated mudmats in clay

As a kind of subsea shallow foundation, mudmats are widely employed to provide temporary support for jacket structures during installation and permanent support for deep-water subsea production infrastructures. Perforated mudmats are increasingly used to facilitate the installation and removal. An upper-bound solution was presented to evaluate the ultimate bearing capacity of solid and perforated mudmats. A series of model tests at 1 g and two centrifugal model tests at 100 g were conducted to examine the impact of loading rate, perforation ratio R, perforation number n(p) and perforation shape. It was found that the bearing capacity factor N-c decreases with perforation ratio R, while the perforation number np and perforation shape only slightly affect N-c at the same R. Finally, the upper-bound method results and test results are in good agreement, which indicates the applicability of the proposed method.