BUCKLING ANALYSIS OF SUPER-LONG ROCK-SOCKETED FILLING PILES IN SOFT SOIL AREA BY ELEMENT FREE GALERKIN METHOD

In bridge engineering, super-long rock-socketed filling piles with high cap are widely used in soft soil area such as Dongting Lake. In order to investigate their buckling stability, the second stability theory and a newly developed numerical method, i.e. the element-free Galerkin method (EFGM), were adopted to consider the non-concordant deformation and the nonlinearity of the pile-soil interaction. Then, based on the nonlinear elastic-ideal plastic interface model, a nonlinear iterative arithmetic was proposed, and the program using arc length method was developed. At last, the present method was applied to analyzing a bridge test pile. A comparison with the loading test results showed that, the calculated pile top load-settlement curve agreed well with the measured one. The relative error between the calculated critical load and the measured ultimate load is only 5.6%, better than that by linear and nonlinear incremental buckling analysis (whose relative errors are 37.0% and 15.4% respectively) based on the first stability theory.