Wind tunnel investigation of aerodynamic interactions between twin high-rise buildings connected by a skybridge at varying installation heights

A modular wind tunnel model was developed and validated to examine the aerodynamic behavior of twin high-rise buildings connected by a skybridge. The model allowed adjustable bridge heights while maintaining geometric accuracy, and its reliability was confirmed through comparison with published data. Wind tunnel tests across eleven bridge height configurations assessed both global aerodynamic responses and local surface pressures. Results showed that adding a skybridge slightly reduced fluctuating lift and torsional base moments of the buildings, indicating potential aerodynamic benefits for structural design. However, aerodynamic loads on the skybridge increased with height, peaking when placed at roof level. Local pressure measurements between the facing building surfaces revealed significant amplification in both mean and fluctuating components. Cross-correlation analysis identified strong negative coupling of crosswind forces between upstream and downstream buildings, while aerodynamic interaction with the skybridge remained limited. Overall, the skybridge demonstrated a dual aerodynamic role, moderately mitigating building responses yet introducing higher local loads. The validated modular approach offers a robust and adaptable framework for future parametric studies and supports data-driven aerodynamic optimization and skybridge placement in tall building systems.