Effect of the sloping seabed on 3D soil-spudcan interaction using a material point-finite element(MPM-FEM)model  

作　　者：Zhengda Lei Guangtian Zeng Huaihui Ren Bisheng Wu Yuxin Jie 

机构地区：[1]State Key Laboratory of Hydroscience and Engineering,Department of Hydraulic Engineering,Tsinghua University,Beijing,China [2]Key Laboratory of the Hydrosphere Sciences of the Ministry of Water Resources,Beijing,China [3]Institute of Ocean Engineering,Tsinghua University,Beijing,China [4]Longyuan (Beijing) Wind Power Engineering Technology Co.,Ltd.,Beijing,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第4期1436-1454,共19页岩石力学与岩土工程学报（英文版）

基　　金：supported by the start-up funding from Tsinghua University(Grant No.100005014).

摘　　要：The sloping seabed affects the bearing capacity and failure mechanism of soil,which may compromise the stability and safety of offshore structures such as jack-up platforms.This paper employs a coupled model combining the material point method and finite element method(MPM-FEM)to analyze the impact of sloping seabeds on the three-dimensional soil-spudcan interaction.The MPM-FEM model implements the B¯approach to solve the challenge of volumetric locking due to the incompressibility constraints imposed by yield criterion.It is validated against the centrifuge results.The effects of sloping seabeds on penetration resistance,soil flow pattern,lateral response,stress distribution,and failure mechanism are discussed.The soil mainly undergoes overall failure when the ratio of penetration depth to spudcan diameter(i.e.D P/D)is between 0 and 0.25.As the slope angle increases,the soil on the side of lower slope is expelled further,resulting in an asymmetric stress distribution and a larger horizontal sliding force of soil.When D P/D increases to 0.75,the soil transitions to localized plastic flow failure,and the range of soil flow affected by the spudcan penetration decreases.The results show that,when the slope angle increases,the lateral displacement and stress distribution on the lower slope of a sloping seabed is significantly larger than that of a horizontal seabed,impacting the spudcan and surrounding soil behavior.The study suggests that the seabed slope significantly affects the range of soil flow and failure at shallow penetration,indicating that the slope angle should be taken into account in the design and installation of offshore jack-up rigs,particularly in areas with sloping seabeds.

关 键 词：Soil-spudcan interaction Centrifuge tests MPM-FEM model B—approach Sloping seabeds Offshore structures 

分 类 号：TU43[建筑科学—岩土工程]