P-y curves method is one kind of nonlinear subgrade-reaction methods; it considers the nonlinear character

layer character

different kinds

and load kinds of ground soil. Starting from the concept of spring joint in Newmark method

the contact nonlinear finite element model is established for the pile-soil system. By the formula of P-Y curves of compound foundation reaction method

the formulas of elastic coefficients of nonlinear springs are deduced. The corresponding programs are organized based on Marc. Based on 1st Taylor stochastic finite element concept

the sensitivities of the displacement on the soil level for soil parameters are computed. By comparing the data of testing pile

the numerical results indicate the rationality and the feasibility of the presented method.