Compressive Support
In structural engineering, pillars support heavy loads above them. They often sit under beams or arches on which walls or ceilings rest. A pillar transmits the weight of structures above it to other structures below it through compression. As a result, pillars have played a large role in allowing mankind to build higher structures and taller buildings that do not collapse under their own weight.
Structural Elements
Pillars can be circular, rectangular or polygonal. Historically in Egypt and the Middle East, pillars were circular and formed of one or many pieces of stone. The pillars often included a slight outward curve down the length to make them appear longer and increase their load-bearing capabilities. Modern pillars, often made of metal or concrete, are usually straight. The material, length, diameter and construction of a pillar dictates its load-bearing capacity, after which a state of instability occurs and it will start to buckle.
Earthquake and Wind Engineering
Pillars are used for the purposes of wind or earthquake engineering. Pillar construction plays an important role in this arena, and a great deal of research goes into finding earthquake-resistant pillar structures. Earthquake-resistant pillars are designed to resist lateral forces and repetitively alternating loads during storms or seismic activity. The arrangement of pillars within a structure is also important in determining the level of seismic activity a building can withstand.
Decorative Features
Stone pillars were commonly used in classical Greek and Roman architecture for both structural and decorative purposes. The entrances of impressive buildings featured awe-inspiring, lavish columns as signs of power or wealth. Of the five types, or "orders," of pillars, each had its own style and proportions. Historians and archaeologists now use these unique styles of columns to date ancient Greek and Roman buildings and to learn about the wealth and power of the inhabitants.