Buckling analysis of super-long rock-socketed piles based on double-parameter foundation model

The Winkler foundation model is widely used in soil calculation for the analysis of buckling failure of super-long piles. The model regards the foundation soil as an elastic body composed of discrete spring elements with the continuity of the foundation soil ignored, which is inconsistent with the actual engineering. In this paper, the double-parameter foundation model which conforms to the actual deformation characteristics of soil is introduced. The model uses two independent parameters to reflect the characteristics of the foundation soil, and the shearing effect between the soil springs is considered to reflect the continuity of foundation soil. Based on this, the total potential energy function of the pile-soil system is established. According to the principle of stationary potential energy and the variational method, the analytical solution of the buckling critical load of the pile foundation can be calculated by the m-method and the combination method respectively. The results of the example show that the error between the calculated method and the test piles is within 5%, which indicates that the double-parameter can accurately reflect the reaction behavior of the foundation soil during the buckling failure of super-long pile in the actual engineering. Meanwhile, the soil resistance model of the combination method is closer to the actual pile body constraint.