High Rise Buildings
Most high-rises have frames made of steel or steel and concrete. Their frames are constructed of columns (vertical-support members) and beams (horizontal-support members). Cross-bracing or shear walls may be used to provide a structural frame with greater lateral rigidity in order to withstand wind stresses.
The foundations of high-rise buildings support very heavy loads, but the systems developed for low-rise buildings are used, though enlarged in scale. These include concrete caisson columns bearing on rock or building on exposed rock itself. Bearing piles and floating foundations are also used.
Low-rise buildings are defined as buildings with 4 floors or under. Mid-rise buildings are defined as buildings that have between 5 to 12 floors. High-rise buildings are defined as buildings that have 13 floors or above. Skyscrapers are buildings with over 40 floors and are considered part of the high-rise category.