Development of Finite-Element-Based Design Procedure for Sheet-Pile Walls.

摘要

The performance of sheet-pile I walls is evaluated using the SOILSTRUCT computer program, which is based on the finite element method. The analysis models the levee-pile system as a two-dimensional plane-strain problem. The analysis includes computations for a field test case and a parametric study of a proposed I-wall section. The principal finding was that traditional limit-equilibrium methods provide a reasonable conservative estimate of pile stability but one-dimensional beam analysis greatly underestimates movements caused by flood and wave loads. One-dimensional analyses do not account for the deep-seated movement caused by the surcharge load of floodwater. The finite element analysis showed that surcharge loading is the major cause of movement in soft clay foundations. It is recommended that conventional stability analyses should be used for design of the sheet pile-levee system; the foundation stability can be addressed by standard slope stability analysis and pile stability can be analyzed using the traditional limit-equilibrium method. The sheet pile should be designed to resist moments computed from the limit-equilibrium pressure diagram for a pile penetration corresponding to a factor of safety equal to 1.0. Charts are provided to estimate 'additional' movements caused by surcharge loading although it is recommended that new finite element analyses be performed when subsurface conditions deviate significantly from those assumed for the parametric study. (SDW)