THESIS
2015
xxiii, 254 pages : illustrations ; 30 cm
Abstract
There is a growing trend to link tall buildings in close proximity by connecting through
horizontal structural links such as skybridges, skygardens, and even skypools. They are
usually built to great heights in order to achieve a grand appearance, so wind-resistance is one
of the primary concerns in design practice, particularly in typhoon-prone areas such as Hong
Kong and Tokyo. Compared to wind-resistant design for a single isolated building,
wind-resistant design for a linked building system (LBS) is much more complicated because
of the link-induced structural coupling and the aerodynamic coupling. Therefore, this study
investigates these two types of coupling systematically and how they affect the performance
of LBSs subjected to wind loads.
First, a simplified continuum be...[
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There is a growing trend to link tall buildings in close proximity by connecting through
horizontal structural links such as skybridges, skygardens, and even skypools. They are
usually built to great heights in order to achieve a grand appearance, so wind-resistance is one
of the primary concerns in design practice, particularly in typhoon-prone areas such as Hong
Kong and Tokyo. Compared to wind-resistant design for a single isolated building,
wind-resistant design for a linked building system (LBS) is much more complicated because
of the link-induced structural coupling and the aerodynamic coupling. Therefore, this study
investigates these two types of coupling systematically and how they affect the performance
of LBSs subjected to wind loads.
First, a simplified continuum beam model of the LBS is developed by modelling each
building as a cantilever beam and the link as a spring-mass system, to investigate the
link-induced structural coupling. The analytical solutions for the modal properties of the
model are then derived. The effects of the linked-induced structural coupling on the modal
properties of the LBSs are preliminarily examined by using these analytical solutions. A more
advanced three-dimensional (3D) evaluation model is then developed for the LBS, to consider
more structural details and wind-excited 3D vibrations of the LBS. Six types of mode shape
are derived from the model and the effects of the link-induced structural coupling on the
modal properties are examined comprehensively. Subsequently, the effects of the link
properties (i.e., mass, location, axial stiffness, and bending stiffness) on the wind-induced
responses of LBSs are examined comprehensively through the model. How the link properties
affect the performance of wind-excited LBSs is investigated in detail and summarized.
The aerodynamic coupling is investigated in terms of the inter-building and
intra-building aerodynamic correlations of LBSs. Spatiotemporal wind pressure data
measured from the wind tunnel tests are used to examine the two types of correlation. Results
show that the wind-induced response of the LBS is related positively to the inter-building
correlation coefficient between the generalized force components of the two buildings.
Furthermore, because of the aerodynamic coupling, the intra-building aerodynamic correlation for LBSs differs considerably from that for the single building, especially for the
correlation between along-wind and torsional force components.
Finally, the combined effects of both structural and aerodynamic couplings on the
performance of wind-excited LBSs are investigated comprehensively. It has been shown that
for the same link, the wind-induced response of an LBS under different aerodynamic
couplings shows significant differences. In general, the response is relatively small when gap
distance ratio (S/B, where Sis the gap distance and B is width of the building) = 0.5 and 1.5,
whereas the response is relatively considerable when S/B = 1. Additionally, two critical wind
directions (i.e., 0° and 90°) are identified. Results show that in design of LBSs, both
link-induced structural coupling and aerodynamic coupling can affect the performance of
wind-excited LBSs significantly and should be carefully taken into account. To facilitate
design of LBSs for wind-resistance, a set of design procedures and charts are provided.
According to these procedures and charts, design of the link can be easily and fast achieved.
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