Thermal-mechanical sequence coupling analysis on the ultimate bearing capacity of embedded foundations in polar marine permafrost

This study presents the results of the numerical simulation analysis, aiming to investigate the temperature effects on the vertical ultimate bearing capacity of the three types of foundations, namely generic spudcan (SGEN), skirted and pile foundations, at different embedded depth ratios H/D (H/D = 1/3, 2/3, and 1 or H/D = 10/3, 5, and 20/3) and strength reduction coefficients s_u,T/s_u0 (s_u,T/s_u0 = 0.1, 0.5). The latent heat effects on foundation bearing capacities are studied by small strain finite element analysis (FEA). The findings from this investigation and previous research indicate that the foundations' vertical ultimate bearing capacity decreases with time, while it increases with increasing the foundation's embedment ratio. For the foundations, the strength reduction coefficient plays an important role in the vertical ultimate bearing capacity. Notably, as the strength reduction coefficient decreases from 0.5 to 0.1, the reduction rate of the vertical ultimate bearing capacity increases by ∼ 3 to 6 times accordingly. Consequently, a normalized bearing capacity coefficient model has been proposed to provide an optimization tool for engineering design in permafrost regions.