Research On Spudcan Foundation Insertion Characteristics Of Jack-Up Wind Power Installation Platform

In the process of offshore wind power resource development and utilization,jack-up wind power installation platforms are often used for the lifting of wind turbine components.The jackup wind power installation platform is equipped with large-size pile boots,which are penetrated into the predetermined bearing soil layer by applying pre-pressure load to ensure the stability and safety of the operation.Marine clay soils exhibit strain rate correlation and strain softening during shear and disturbance.In this paper,a coupled Eulerian-Lagrangian(CEL)numerical model considering strain softening and strain rate effects in clay is developed by using a user subroutine compiled in FORTRAN language for secondary development of clay intrinsic model in ABAQUS.Based on the improved numerical model,the effect of soil material parameters and pile shoe shape parameters on the penetration of the rectangular pile shoe is investigated in single-layer clay soils and upper hard and lower soft clay soils.The main research contents and conclusions are as follows:The current main methods for calculating the pile shoe inserted pile bearing capacity are analyzed and summarized,and their applicability is clarified,so that the existing calculation methods cannot consider the effects of clay strain softening and strain rate effects and specific pile shoe shape on the penetration resistance of rectangular pile shoe;in ideal soil,the simulation results of rectangular pile shoe penetration are compared and verified using the established numerical model,and the grid size of the encrypted area of the numerical model and the pile shoe In the ideal soil,the simulation results of rectangular pile shoe penetration are compared and verified by using the established numerical model,and the influence of the grid size and penetration speed of the encrypted area of the numerical model on the calculation results is investigated.The numerical models considering strain softening and strain rate effects of clay soils are compared and validated with the results of centrifuge tests in single-layer clay soils,and the effective soil weight,soil strain softening parameters,soil sensitivity,soil strain rate parameters,soil reference shear strain rate,slope of linear increase of soil strength with depth and equivalent pile shoe diameter of rectangular pile shoe,rectangular pile shoe aspect ratio,rectangular pile shoe taper angle,rectangular The influence of the length of the skirt of the rectangular pile shoe and the area reduction rate of the rectangular pile shoe on the vertical bearing capacity of the pile shoe and the ultimate return depth of the soil.In the upper hard and lower soft clay layer,the numerical model considering strain softening and strain rate effect of clay is compared with the centrifuge test results,and the effects of upper and lower soil strength ratio,upper soil relative thickness,lower soil nonuniformity and rectangular pile shoe equivalent pile shoe diameter,rectangular pile shoe aspect ratio,rectangular pile shoe cone angle,rectangular pile shoe skirt length,and rectangular pile shoe area reduction rate on the vertical bearing capacity and ultimate depth of soil flowback of pile shoe are investigated.The effect of soil return depth.