Soil, Foundation, and Superstructure Interaction (I): Advanced Analyses of Shallow Foundations

Abstract

The analyses of shallow foundations are mainly based on the assumption of Taylor (1948). Taylor (1948) assumed uniform contact stresses under footings. Until now, this assumption has been widely used as an appropriate assumption. Since that early date, researchers have been interested in studying the real distribution of the contact stress. Strip foundations are typically used in building construction, so researchers considered this footing in their experimental measurements of the contact stress. In this paper, the comparison is established between the contact stress distribution of the finite element method (FEM) using different soil models and the measured distribution under strip footing. The contact stresses are found to be concentrated near the edges and slightly lower under the footing center. This distribution resulted from experimental measurements and FEM using Mohr-Coulomb soil model. Additionally, the effects of the soil type and depth of footing embedment on the analyses of the strip footings are investigated. The paper also discusses the analyses of the isolated and the combined footings using 3D FEM. For the studied footings, the contact stresses are concentrated near the edges and low under the footing center. The concentrations near the edges have long arms when calculating the maximum bending moments (Mmax). Therefore, the resultant moments from the real distribution under a single footing are always more than those obtained using the Taylor assumption. Real distributions of the contact stresses under shallow foundations should be investigated using large-scale models in field.