Behavior of Soil Heave Inside of Stiffened Caissons Installing in Clay

Abstract: Length of suction caisson anchors increases to support increasing dimensions and weight of floating facilities. This necessitates employing horizontal ring stiffeners at intervals along the inner wall of the thin skirt of caissons to ensure structural integrity. The addition of these stiffeners has created significant uncertainties regarding the soil flow mechanisms, in particular the soil heave inside the caisson, which may reduce the caisson final penetration depth and influence the process of installation due to the need to avoid inside soil suction into the pumping equipment. This paper reports results of large deformation finite element (LDFE) analyses investigating the soil heave inside stiffened caissons during installation in non-homogeneous clay deposits, with the corresponding evolution of soil flow mechanisms and penetration resistance profiles reported in Zhou et al. (2016). The LDFE analyses have simulated continuous penetration of stiffened caissons from the seabed surface. A detailed parametric study has been undertaken, exploring the relevant range of soil strength non-homogeneity and normalized strength, stiffened caisson geometry, soil effective unit weight and caisson roughness. Of particular interest was the influence of stiffeners on soil heave and potential penetration refusal.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author