Stability Evaluation of Planar and Circular Sheet Pile Wall in Sand and Clay Using Finite Element Limit Analysis
摘要
The sheet pile wall is one of the choices of a retention system for deep excavation in a range of soils including clays, sands and sometime in partially weathered rocks. Mostly, the stability of sheet pile wall is evaluated considering the plane strain condition. However, if the sheet pile walls are installed such that, in plane, it forms curvature, also called circular sheet pile wall, and are subjected to axisymmetric loading conditions. Therefore, in this study, the stability of circular sheet pile wall in undrained clayey soil with different curvature in plan considering the Tresca soil model is evaluated using axisymmetric formulations in finite element limit analysis-based software OPTUM G2. Accounting different soil models, the series of vertical excavations is simulated considering the wall height H = 15 m of rigid and flexible wall, different excavation depth (h), embedded depth (D) and different soil properties as unit weight (γ), cohesion (c), angle of internal friction (ϕ), undrained shear strength (su) and sheet pile placed at varying radius (R) to account the curvature. The stability of the same sheet pile wall considering plane strain condition is evaluated to account the stability solutions from axisymmetric to plane strain conditions. The undrained stability results are presented as normalised stability number and are compared with those available in the literature. The presented study results are illustrated in the form of design charts of dimensionless parameters, which are the relationships between the factor of safety, wall-excavation height ratio (h/H) and wall-embedded depth ratio (D/h). An attempt is also made to evaluate the stability number for the case of sheet pile wall in sand considering drained analysis.