The p-y curve analysis of large diameter monopiles based on piezocone penetration test
[Objective]The p-y curve method for laterally loaded piles has been widely used to describe pile-soil interactions and predict pile behavior under lateral load,especially in the theoretical analysis of large-diameter monopiles for offshore wind tur-bines.As an in-situ test method with high efficiency and good accuracy,piezocone penetration test(CPTu)overcomes the short-comings of disturbance and poor accuracy of soil samples in the process of obtaining geotechnical parameters in conventional labo-ratory tests.CPTu records three continuous measurements(modified cone tip resistance q,,sleeve friction resistance fs and pore water pressure u2)and evaluates physical and mechanical properties of the soil strata,which can be incorporated into p-y curve model.[Methods]This paper uses the CPTu data from a certain area in the Bohai Sea,China,and the following study tasks were completed:(1)Classification of the marine soil of the site and determination of the physical and mechanical properties by CPTu including soil density,elastic modulus,effective friction angle and cohesion intercept,(2)Aforementioned CPTu-interpre-ted properties served as the input in a three dimensional finite element analysis to model a 5-meter diameter laterally loaded steel pipe pile's response with a maximum load of 20 MN,(3)A new CPTu based formula to calculate the ultimate soil lateral capaci-ty is proposed and;(4)The relevant parameters in the existingp-y curve model are interpreted by CPTu,and then the above p-y curve model is compared and analyzed.[Results]In this paper,a CPTu based p-y curve formula for complicated soil stratifica-tion is established and validated through comparison with FEA,and showed a reasonably agreement.[Conclusion]The result show that the soil resistance formula based on CPTu proposed in this paper can quickly and accurately reflect the horizontal load response of large-diameter monopiles.This formula not only provides strong theoretical support for the engineering practice of large-diameter monopiles in the Bohai Sea,but also provides insights for the engineering design and analysis of similar situated foundation structures in the marine environments.
p-y curvecone penetration testfinite element methodlateral loaded pileslarge diameter monopilessoil resist-anceeffective stress parameters of soilmechanical properties
万方数据
维普
