Nowadays, every multi-story building (residential, commercial, industrial, etc.) requires an open ground story for parking space, lobbies, conference halls, banquet halls, etc.
So the ground floor needs to keep free without construction except for columns. Conventional columns which are closely spaced are not preferable on ground floors. To avoid this, discontinuity in columns is required, and here floating column comes into existence.
What Is Floating Column?
Floating column is a type of column that is constructed over beams or slabs of any intermediate floors of a structure. These columns are not attached to any footings or pedestals. Floating columns are also known as hanging columns. (Refer to the below image)
How Load Transfers In Floating Columns
The load-transferring mechanism in floating columns is totally different from ordinary columns. In ordinary columns, the load is transferred from the column to the foundation and then to the surrounding subsoil.
But floating columns do not transfer loads directly to the foundation. Instead, they transfer loads to the beam or slab on which they are constructed, and the load acts as a point load.
Advantages Of Floating Columns
1. Floating columns are mainly used to fulfill the architectural requirements of a structure. They are very useful when the lower floor has a large span hall having rooms on its upper floor such as hotel, auditorium, etc.
2. They are useful in the construction of soft storeys.
3. The plan on each floor can be varied.
4. The rooms can be divided and some portions can be raised without raising the whole area.
Disadvantages Of Floating Column
1. The main disadvantage of floating columns is it suffers from an earthquake. Beams supported by these columns may experience a large amount of shear, bending, and torsion. However, this problem can be redeemed but is still not advisable in case of lateral loading.
2. As stated above, it attracts extensive forces.
3. It increases storey displacement in buildings.
4. As the columns do not rest on primary continuous columns, discontinuity happens with the below and above columns which makes them vulnerable.