Use of Modal Substructure Method to Improve Wind-Resistance Design of Twin Towers

To provide guidance for the wind-resistant design of super-tall twin towers, this study proposes a new method for the wind-induced response computation and wind-resistant design optimization of twin towers, named the Modal Substructure (MSS) method. The MSS method is established through theoretical deduction, which is utilized to investigate the effects of links on the structural dynamic characteristics of twin towers via parameter analysis. The results show that, in the in-phase mode, the structural link increases the generalized mass of the “linked tower” system but insignificantly affects its stiffness and damping. However, in the out-of-phase mode, the link increases the overall damping and stiffness of the “linked tower” system, with negligible effects on the inertia characteristics of the entire structure. Finally, the accuracy of the MSS method is validated using 570 m-high twin towers as a case study. It was found that although the MSS method is an approximate approach, its results exhibit good accuracy and convenience in exploring the impact of link properties on the dynamic characteristics of twin towers. Therefore, the MSS method can be effectively used to guide the wind-resistant design of linked twin towers.