*1.3. Motivation of Present Study*

Most existing research on the stability of spudcans during reinstallation nearing footprints is from centrifuge tests and theoretical analyses. In this study, the reinstallation of flat base footing, fusiform spudcan footing and skirted footing near existing footprints are simulated using the coupled Eulerian–Lagrangian (CEL) method. The effects of footprints' geometry, reinstallation eccentricity and the roughness between spudcan and soil on the profiles of vertical force, horizontal force and bending moment are discussed. One purpose of this study is to reveal the mechanisms of those factors which affect *V, H,* and *M* profiles during reinstallation, by presenting the soil flow mechanisms of selected cases.

The other purpose is to discuss the effect of footing geometry shape during reinstallation near existing footprints. Flat base footings, fusiform spudcan footings, and skirted footings are investigated in this paper. Fusiform spudcan footings have been widely used in practice. Skirted footings have been proved to have some potential in bearing capacity and mitigating punch-through failure, but its behavior in mitigating footprint hazards is still not very clear. Flat base footings have advantages in eliminating the uncertainty when discussing the soil flow mechanism, by comparing with fusiform spudcan footings of which the reverse cone initially touches the seabed. Besides, some large footings in practical engineering have a relatively flat base, such as HYSY 944, as shown in Figure 2.
