INTRODUCTION
The Wind is air in motion relative to the surface of the earth.
It varies with time and space. Due to unpredictable nature of
wind, it is necessary to design the structure by considering the
critical effect of the wind on the it. The motion of wind is
always governed by the state of its surrounding conditions.
The wind forces depend upon terrain and topography of
location well as the nature of the wind, size, and shape of the
structure and dynamic properties of the structure. As the wind
encounters a structure, it exerts positive pressure on the
windward face.
Every physical conformation of a building will react to wind
flow lines in distinctive manners. Some surfaces, planes or
points would help deviate the flow lines or would converge
them. Deviation in wind flow away from the building surface LITERATURE REVIEW
With the perfect and over the conventional correlation
approach between Architecture and Engineering, has resulted
in creating the landmark in the world. It is very important to
understand phenomena of wind over the building form to
counteract the wind pressure on the structure. Further, the
design of tall buildings is not limited to wind sensitive design
but rather using wind to the advantage of building.
The wind behavior can be classified into various phenomena.
“Cross-wind” actions usually govern in design of very tall
buildings; especially interference effects magnify these
effects. Interference from buildings located in close proximity
to the proposed building can cause large increases in crosswind responses. The designer should not only consider the
existing conditions but make allowance for future changes in
the surrounding area during the design life of the structure.
There are several different phenomena giving rise to dynamic
response of structures in wind. These include buffeting, vortex
shedding, galloping and flutter. Slender structures are likely to
be sensitive to dynamic response in line with the wind
direction as a consequence of turbulence buffeting. Transverse
or cross-wind response is more likely to arise from vortex shedding or galloping but may also result from excitation by
turbulence buffeting. Flutter is a coupled motion, often being
a combination of bending and torsion, and can result in
instability. For building structures flutter and galloping are
generally not an issue. (J. & B., 2007)
The wind response is largely determined by building shapes.
Buildings with rounded forms, rather than rectangular forms
with flat surfaces, offer less wind resistance (Figure 1). Tall
buildings that are short in horizontal dimensions are more
critical for overturn and possibly for the total horizontal
deflection at their tops (Figure 2). Open-sided buildings or
buildings with forms that cup the wind tend to catch the wind,
resulting in more wind force than that assumed for the general Source: International Research Journal of Engineering
and Technology (IRJET)
The plan form of a building affects the airflow around and
through it. It could either aid or hinder the natural flow of
wind. Physical obstacles in the path of airflow create pressure
differences. This causes a new airflow pattern. Air tends to
flow from high pressure areas. Knowing the direction of air
movement, the plan form can be determined also as to create
high pressure and low pressure areas. Building openings
connecting the high pressure areas to low pressure areas
would cause effective natural ventilation. (Nirmal, 2017) TOWER FORM: The floor plan of the Tower consists of a triaxial, Y-shaped plan, formed by having three separate wings
connected to a central core. As the Tower rises in height, one
wing at each tier “sets back” in a spiraling pattern, further
emphasizing its height. The result is 24 different primary floor
plates (plus some less major variations), creating a stepping
geometry that presents multiple building widths over the
height of the building, providing an environment that
“confuses the wind”—the wind vortices never get organized,
because at each new tier the wind encounters a different
building shape. Starting from a slender top, the building
spreads out as the gravity and wind forces accumulate. As a
result, even though the global forces are large, the forces in
the individual members are not.
Several revisions to the building were made. Some were
related to the geometry of the Tower: the size and shape of the
wings were the setbacks changed throughout the process, as
were their locations: the original massing had the setbacks
occurring in a spiralling counter-clockwise pattern, which was
revised to be in a clockwise direction. Taken together, these
measures had a significant impact in encouraging
disorganized vortex shedding over the height of the Tower.
Another revision was related to the orientation of the building