Accurate estimation of the dynamic structural response to wind excitations is crucial to the wind-resistant design of tall buildings, which is commonly done by the high frequency base balance (HFBB) testing technique. The recent trend of constructing tall buildings in city centers with high proximity of surrounding buildings increases the occurrence and significance of wind interference effects. Such interference effects significantly alter the characteristics of the wind loads on the tall buildings, and can significantly affect the performance of the HFBB methods. The principal objectives of this research are to identify the interference effects on a benchmark rectangular wind-sensitive tall building in a region where there are short and tall surrounding buildings, investigate...[ Read more ]

Accurate estimation of the dynamic structural response to wind excitations is crucial to the wind-resistant design of tall buildings, which is commonly done by the high frequency base balance (HFBB) testing technique. The recent trend of constructing tall buildings in city centers with high proximity of surrounding buildings increases the occurrence and significance of wind interference effects. Such interference effects significantly alter the characteristics of the wind loads on the tall buildings, and can significantly affect the performance of the HFBB methods. The principal objectives of this research are to identify the interference effects on a benchmark rectangular wind-sensitive tall building in a region where there are short and tall surrounding buildings, investigate the change of the wind force characteristics due to the interference effects, and evaluate the corresponding effect on the performance of the HFBB methods.

The wind tunnel test data of three interfering models are analyzed and five interference effect mechanisms are identified. The results show that the location and strength of the interference effect mechanisms depend on the height of the interfering buildings. Based on the study of the interference effect mechanisms, the interference effects on the wind force characteristics on the benchmark building are investigated.

The interference effects on the HFBB methods due to the changed vertical distribution of the fluctuation component of the local wind forces are investigated. In-house non-coupled mode shapes are created based on the original mode shapes of the benchmark building. The performance of the HFBB methods, under a power law distribution assumption and a uniform distribution assumption of the local force spectrum distribution, are compared in the in-house mode shape. The results show that the uniform distribution assumption of the local force spectrum distribution is unreliable and the power law assumption is necessary under conditions with interfering effects. The interference effects on the HFBB methods due to the changed cross-correlation conditions of the local wind forces is also investigated. The performance of the HFBB methods, under no and full correlation assumptions between the local forces, are compared in the in-house mode shape. The results show that the performance of the no correlation assumption is better than the full correlation assumption in torsional wind excitation. Coupled mode shapes are created and tested. For coupled mode shapes, each base moment should use the corresponding HFBB method, based on the cross-correlation condition of the wind excitation.