基于ANSYS的近海工程桩基础p-y曲线研究

海上风电机组体积庞大,桩基础需要承受很大的上部结构风压、波浪和自重等荷载的作用,为保证机组正常运行,需要对桩土相互作用进行研究。侧向受荷桩在近海工程中有着十分广泛的应用,p-y曲线法是分析侧向受荷桩桩土非线性相互作用的重要方法。不同土层土体参数各异,粘土和砂土的p-y曲线公式也不相同。采用我国海洋工程常用的API规范法分析土体相关参数,通过p-y曲线分析了混合分层地基的桩土作用相关特性,并且利用ANSYS中的COMBIN39单元实现桩土相互作用仿真计算,绘制出了单元等效应力云图和弯矩分布云图。计算结果表明,在产生相同位移时粘土中的土抗力比砂土要小得多。单桩在风浪等荷载作用下,最大弯矩发生在水面附近;最大位移发生在平台顶部,且最大位移可达0.35 m。研究成果可为近海工程桩基础和平台安全保护提供参考依据。

ANSYS-based study on p-y curve of pile foundation for offshore project

As the volume of offshore wind turbine unit is huge， of which the pile foundation must bear the effects of the loads from the wind pressure of its upper structure， wave， self-weight， etc.， it is necessary to study the pile-soil interaction， so as to ensure the normal operation of the turbine unit. The laterally loaded pile is widely applied in the construction of offshore project， while the p-y curve method is an important method for analyzing the nonlinear pile-soil interaction of the laterally loaded pile. As the parameters of soil mass in various soil layers are different， the p-y curve formulas for clay and sand are different as well. The relevant parameters of soil mass are analyzed with the API standard method normally used in the construction of marine project in China and the relevant characteristics of the pile-soil interaction of composite layered foundation are analyzed through p-y curve， and then the simulative calculation of the pile-soil interaction is realized with the COMBIN39 unit in ANSYS; from which both the unit equivalent stress nephogram and the moment distribution nephogram are drawn. The calculation result shows that the anti-force in clay is much less than that in sand for the same displacements. Under the effects of wind and wave， the maximum bending moment of a single pile occurs near the water surface， while the maximum displacement occurs at the top of the platform and its maximum value can reach to 0.35 m. The study result can provide a reference basis for the safety protection of the pile foundation and platform of offshore project.