Introduction:- Strictly Speaking any building having more than one floor is a Multi Storied Building and a building to which provision of lift is essential is Tall building. Various nomenclatures used for tall buildings are high rise buildings, sky scrapers, vertigoes, anthills, concrete castles etc. From architectural considerations any building higher than two floors, needing use of staircase or lift is called as tall building. From fire fighting view a tall building is one from where emergency escape is not practicable. From structural engineering aspect, a tall building would be one whose structural elements directly or indirectly are affected by wind forces. From physical planning a tall building is one which by its height begins to affect its light, ventilation and climate of other surrounding buildings.
For all practical purposes, a building with more than one floor needing staircase is a multi story building, while a tall building means a building which requires use of mechanical services like lifts. Building more than 50 Stories are now a days are called as Ultra – High buildings. A new terminology has been used to very tall buildings is Super tall (More than 100 m height), Mega tall (more than 600 M height) a new era entering into construction industry. The changing scenario of tall buildings is as shown in Figure 1. It is not necessary to have symmetrical structure but it is essential to have balanced structural form / systems. Expansion joints if required should be provided, properly designed.
Structural System for Tall Buildings:- Various structural systems used in design for tall buildings, concrete as an structural materials are