Generalized Lower-Bound Bearing Capacity Analysis of Shallow Inverted Triangular-Based Strip Footings

Abstract

This paper pertains to the finite-element lower-bound bearing capacity analysis of inverted triangular-based strip footings (ITBFs). The solutions are obtained by the construction of a linear stress field that satisfies all the equations of equilibrium, which is the same as that developed by Lysmer in 1970; however, they were modified in conjunction with a nonlinear programming technique (active set algorithm) to isolate the optimal solution. Studies have been conducted on the convergence of the solutions (by varying the number of triangular elements), and the extensibility of the chosen stress field was confirmed by extending the mesh and comparing the solutions that were obtained. Parametric studies were carried out by varying the cone apex angle (β), for relevant soil properties and different values of the coefficients of earthquake acceleration [horizontal (αh) and vertical (αv)]. A close examination of the obtained results shows that they were as expected and were similar to those of conical footings.