Armando N. Antão

Influence of tension cut-off on the stability of anchored concrete soldier-pile walls in clay

A previous paper studied the stability of soldier-pile walls in clay under vertical loading using upper bound analyses. A classical Tresca yield criterion was assumed in that analysis. This paper extends that study by considering a tension truncated Tresca yield criterion in an upper bound numerical analysis of the problem. It shows that assuming zero tension soil strength has a significant influence on the values of the minimum soldier-pile resistance required to ensure stability.

PROBABILISTIC ANALYSIS OF BEARING CAPACITY OF SHALLOW FOUNDATIONS USING THREE-DIMENSIONAL LIMIT ANALYSES

Strip shallow foundations on random heterogeneous soil responding in undrained conditions are analyzed using three-dimensional upper limit analysis and Latin Hypercube sampling. The results obtained considering the three-dimensional variability of soil are compared with results using plane models, showing significant differences in terms of both mean and standard deviation of bearing capacity. An averaged two-dimensional model fitted to a small set of three-dimensional samples is shown to yield accurate predictions of the bearing capacity distribution.

A novel augmented Lagrangian approach for Limit Analysis computations

In this paper, we introduce a novel upper bound formulation of Limit Analysis applied to plane strain problems. This formulation can considered to be a variant of an existing two-field mixed formulation based on the augmented Lagrangian method also developed by the authors. In contrast to the previous formulation, two independent field approximations are now used to define the velocity field, globally and at element level. It is shown that this feature allows a governing system of uncoupled linear equations to be obtained. Our main concern is to achieve a formulation with appropriate characteristics for implementation in an efficient parallel algorithm. Some numerical examples are presented in order to illustrate the current model performance.