New Iterative method to Calculate Base Stress of Footings under Biaxial Bending

Abstract

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.