Analysis of the displacements and bending moments in the foundations and in the columns of a bridge in reinforced concrete considering the soil-structure interaction

Abstract

This article presents an analytical and numerical study on the resulting displacements and bending moments in the column-caisson foundation set of reinforced concrete bridges, considering the soil-structure interaction (SSI). In the analytical study, the method of Matlock and Reese (1961) and the differential equation on elastic basis were used and, in the numerical study, modeling was carried out via the finite element method (FEM). From the results, the way of obtaining the horizontal soil constant – through empirical equations or results of load tests – interferes with the resulting displacements. Furthermore, the method by Matlock and Reese (1961) presented results similar to those obtained numerically, through the model with linear elastic supports along the depth of the foundation. On the other hand, the numerical model with elastic supports resulted in values greater than twice the average displacements obtained through the numerical model that considers the soil with infinite stiffness. This shows that, in the specific case under analysis, the bridge would have displacement levels much higher than those predicted in the project, which would enhance the second order effect on the structure, potentially causing irreparable structural wear or even structural collapse.