Studying About Extraction Resistance Of Spudcan In Double Layer Soil

Jack-up rigs are important in the exploit of offshore oil and gas resources in China.Difficulties may encountered during the extraction of spudcan because of insetting into the soil too much in the Operating area with a weak bearing capacity.The accurate prediction of the extraction resistance is of great significance to ensure the safety of jack-up rigs.There is no mature way to calculate the maximum extraction resistance of the spudcan.The extraction resistance was divided into three parts: the upper resistance,suction force,and side friction by in this paper.By analyzing by CEL model based on Mohr-Coulomb model,Spudcan area,soil shear strength and hard soil thickness are supposed to influence the maximum extraction resistance.Then extraction resistance calculation formula in double layer soil within a certain range is fitted out.The development of suction force was studied with a finite element model for seepage analysis.Suction force is influenced by soil consolidation time,permeability coefficient and depth into the mud,its calculation formula with a certain range is fitted out.Considering the comprehensive influence of the upper resistance,suction force,and side friction,A calculation formula of the maximum extraction resistance in double layer clay was put forward and its effectiveness was verified by Muhammad’s experiment.The result of the formula is in this paper is more accurate than the original empirical formula,so a good reference for spudcan extraction is provided.