在考虑了土的自重产生的围压对土极限承载力的影响后,利用Mohr-Coulomb屈服准则得到了土的极限承载力沿深度的变化关系,并采用双曲线函数来描述这一关系.在对几种p-y曲线的特性进行探讨后,建议采用双曲线函数p-y曲线,再由p-y曲线确定的土弹簧系数建立桩的非线性动力微分方程,给出了非线性方程的差分解.为便于工程应用,还给出了桩的简化分析方法.在简化分析方法中桩被划分为埋入土中和自由两部分,桩的非线性特性通过改变自由部分长度考虑.最后用数值算例来说明进行非线性分析的必要性及简化分析方法的可靠性.
After considering the effects of confining pressure caused by soil gravity on the ultimate resistance, the relationship between the ultimate resistance and the depth of soil is obtained based on Mohr-Coulomb failure criterion, and a hyperbolic function is proposed to describe this relationship. After investigating the characteristics of several types of p-y curves, the hyperbolic p-y curves are adopted. From these curves, the stiffness coefficients of soil are derived, and a non-linear dynamic differential equation is established with its difference solution presented. To facilitate engineering application, a simplified analysis method is proposed, in which the pile is divided into embedded and free segments and the non-linear properties of pile are taken into account by modifying the length of free segments. Numerical example demonstrates the necessity of non-linear analysis and the reliability of the simplified solutions.