Slit‐connected coupling beams for tunnel‐form building structures

Openings to provide functional use in shear walls of tunnel‐form buildings result in coupled shear walls and coupling beams. These beams are deep compared to their clear span above the door openings; however, their thickness is less than 250mm. Moreover, they are subjected to high shear forces under lateral loads. Dimensional constraints make their design against high shear forces difficult when code‐specified reinforcement configurations are applied. In this paper, slits at each end of coupling beams are proposed to decrease the shear stiffness and shear forces of these deep coupling beams. The structural behavior of coupled shear walls with slit‐connected coupling beams (SCCBs) is investigated by performing two‐dimensional static and dynamic analyses. Stiffness terms of SCCBs are obtained as a result of extensive finite element simulations. Based on the parametric study conducted, an equivalent prismatic beam model representing SCCBs is proposed. Thereby, coupled shear walls having SCCBs can be analyzed by the equivalent frame method using the equivalent prismatic beam model.