Study on p-y curve of large diameter pile under long-term cyclic loading

Abstract

The pile foundation used in offshore wind turbine system is located in a complex marine environment and is subjected to various long-term cyclic loads such as wind, wave and current. However, the attenuation effect of long-term cyclic load on seabed soil has not been considered by most of the existing p-y curve calculation models. In order to solve this problem, the finite element numerical model of pile-soil interaction of large diameter single pile foundation of offshore wind turbine is established in this paper. Based on the Stokes second-order wave theory, the time history curve of wave and current loads on piles with different diameters are derived and calculated by programming. Then the soil stiffness attenuati on model subjected to marine cyclic loading is embedded into the finite element model by subroutine. Considering the influence of the number of ocean load cycles on the ultimate soil resistance of the soil around the pile and the initial foundation reaction modulus, the calculation results of different pile diameters and soil depths are analyzed and regressed. Finally, the p-y curve calculation model of large diameter single pile foundation of offshore wind turbine under long-term ocean cyclic load is obtained.