Interaction-Based Design Formulas for Transfer Beams: Box Foundation Analogy

The design and analysis of transfer beams that support in-plane loaded shear walls have been receiving added emphasis of late due to their importance in connection with the design of tall buildings. The current practice in designing the transfer beam–shear wall systems does not generally consider the significant interaction of the transfer beam and the upper shear walls, thus leading to an unreasonable design for the internal forces of structural members and the corresponding steel reinforcement detailing. This paper presents interaction-based design formulas, which are derived by use of a box foundation analogy, for determining the bending moment and axial force of the transfer beams that support the in-plane loaded shear walls. The design formulas have been shown to provide practicing engineers a very simple and efficient, yet accurate, means of calculation of the bending moment and axial force in the transfer beams.