Numerical Modeling of Spread Footings at Bridge–Embankment Interfaces

The use of spread footings on slopes is a common practice in the design of bridge foundations. Footings generally are constructed in the slope or at its crest to minimize the bridge length, thereby minimizing costs. However, the analytical methods that frequently are used to predict the ultimate bearing capacity of shallow spread footings on slopes yield a wide range of solutions. There has been an increased effort in recent years to evaluate and improve techniques for predicting the deformation and ultimate bearing capacity of shallow spread footings located on or near slopes. Research in the development of numerical techniques used in conjunction with sophisticated elastoplastic constitutive models continues to be an area in which additional effort is needed. Physical model tests were used to obtain maximum bearing pressures of shallow spread footings located near sand slopes. These results were compared with classical bearing capacity solutions and numerical predictions obtained with finite element discretizations. Deformed meshes and incremental nodal displacements are presented.