Numerical Evaluation on Consolidation Settlement of Suction Caissons in Marine Environment

Consolidation settlement analysis is a necessary part of the design process for suction caissons. However it is a complex task since soil volume important for settlement analyses is mainly affected by the installation process. Consolidation settlements have been found to be the critical design criterion in several particular subsea projects. Therefore performing adequate and comprehensive analysis seems inevitable. The finite element method (FEM) has been used to consider the consolidation process after completed installation of the suction caisson. Studying of shear strength increase with time along the skirts has been done. During consolidation settlement, dissipation of excess pore pressure result in higher effective stresses. Consequently the modeled caisson undrained shear strength increases. Adequate modeling of the changes in the interface zones adjacent to the caisson walls during consolidation is vital for correct prediction of long term settlements. Modeled undrained shear strength have huge impact on the analysis results due to different mobilization of the surrounding soil. Appropriate evaluation of soil structure interaction is essential to assess the reliability of the analysis. The results were found to be reasonable with respect to final consolidation settlements and development of mobilized shear strength with time

Keywords:

Suction Caisson , Consolidation Settlement , Undrained Shear Strength