New Iterative method to Calculate Base Stress of Footings under Biaxial Bending
Base stresses of the footings should be calculated under biaxial bending especially for structures in seismic zones. However, calculation of the base stresses is not easy for the footings with large eccentricity due to the fact that interaction of the stresses in both directions should be considered and redistribution of stresses is required in zero stress zone. In this study new iterative method is presented to calculate the base stress of rectangular footings under biaxial bending. A computer program is developed according to this method. A design example (single footing having rectangular shape) is analyzed using the developed program and computed base stresses are compared to previous results in order to test accuracy of the method. The design example is also analyzed using different eccentricities in order to reveal efficiency of the redistribution under biaxial bending.
ABSTRACT The article presents the results of an experimental and numerical investigation on Azzone Visconti bridge, a 14th century arch bridge in Lecco (northern Italy). Starting from the historical data and from an extensive mechanical characterization of both the soil constituting the riverbed and of the masonry constituting the piers, the aim of the study is to investigate the bearing capacity of the bridge. A testing loading scheme defined according to the current Italian Code is adopted to check the structural behavior. A simplified finite element structural model was conceived and calibrated as a control tool to safely perform the experimental tests. Post-test nonlinear finite element analyses have allowed the prediction of the bridge bearing capacity and the definition of the bridge class according to the Italian regulations.