3. DEFINITION OF TALL BUILDINGS
From the structural design point of view, it is simpler to consider a building as tall when its structural analyses and design are in some way affected by the lateral loads

5. Introduction
For the structural engineer the major difference between low and tall buildings is the influence of the wind forces on the behaviour of the structural elements. Generally, it can be stated that a tall building structure is one in which the horizontal loads are an important factor in the structural design

6. PLANAR LATERAL LOAD RESISTING ELEMENTS
Rigid-jointed Frames
A rigid frame, also called a moment frame is a vertical support system that also serves as a lateral load-resisting system. It is constructed with beam and column elements either rigidly
or semi rigidly joined together with moment-resisting connections.

8. The rigid frame derives its unique strength to resist lateral loads from the moment interaction between beams and columns. The moment restraint at the ends leads to reduced positive bending moments for beams and reduced effective lengths for columns under gravity load

10. 2. Braced Frames:
The lateral stiffness of a rigid frame can be improved significantly by providing diagonal
members.
Bracing can be either in storey height-bay width module or they could extend over many bays and stories.

20. FRAME TUBE SYSTEMS
The idea here is to develop a fully three-dimensional structural system that engages the entire building inertia to resist lateral loads. The goal is to achieve a higher degree of efficiency toward lateral load resistance for taller buildings. The resulting organization for a framed tube system is generally one of closely spaced exterior columns and deep spandrel beams rigidly connected together