Study On The Influence Of Spudcan Installation Process On Bearing Capacity Of Adjacent Spudcan

Jack-up drilling platform is a special kind of mobile ocean engineering vessel.In recent decades,it has been widely used in offshore oil engineering.Jack-up drilling ship often uses spudcan as a support structure.During drilling operation,the spudcan penetrates into soil to support the hull and superstructure.After the operation is completed,the spudcan can be pulled up to move the hull.Drilling platform will squeeze soil and exert a certain influence on the foundation of the adjacent wellhead platform by penetration and extraction.Combined with practical engineering project,the effects of the spudcan penetration and extraction on the spudcan foundation of adjacent wellhead platform are obtained in this article.The main contents of the research are as follows:(1)Traditional formulas of soil mechanics,model tests and FEM are adopted in this research to find the range of effect of penetration and extraction of the spudcan on the surrounding soil.The results show that the relative sand density is reduced after penetration and extraction of spudcan,and gradually recovers with the increase of the distance from the spudcan.The affected area of the surrounding soil is the annular range of 1D(D is the diameter of the spudcan)outside the edge of the spudcan.(2)Small scaled model tests are carried out in sandy soil,to study the influence of spudcan penetration and extraction on the bearing capacity of the adjacent spudcan foundation.The results show that the bearing capacity of adjacent spudcan is reduced due to the penetration and extraction of spudcan.The reduction rate of the bearing capacity decreases as the relative spacing increases,and increases as the relative depth increases.When the relative spacing of the two spudcans is greater than 2D,it can be considered that the spudcan penetration and extraction have no effect on the bearing capacity of the adjacent spudcan foundation.(3)Quasi-static numerical simulation method is used to effectively simulate the influence of the spudcan penetration and extraction on the bearing capacity of adjacent spudcan.Through the numerical simulation of different relative spacings,different relative depths and different spudcan diameters,the calculating method of bearing capacity of adjacent spudcan affected by the penetration and extraction of spudcan is established.