The word demolition means destruction, breaking down or removal. Demolition of building is the process of dismantling or destroying of a structure after its life of serviceability by pre-planned and controlled methods.
Different steps are involved in the process of demolition of building structures which are:
•Surveying
•Removal of hazardous materials
•Preparation of plan
•Safety measures
There are two types of demolition methods used for buildings and structures:
•Non-explosive demolition
•Explosive demolition
Non-explosive demolition:
It means the demolition of a structure done with some equipment without the use of any explosive. Different equipment’s used for the demolition activity are Excavators and Bulldozers,
Wrecking Balls etc
Explosive demolition:
Implosion Method of Building Demolition, Implosion is the process of demolition of a building using explosives. If the supports of the building are removed, the structure collapses.
Using implosion technique, the main supports of the buildings such as column’s, beams and slab are fixed with explosives. When these explosives are detonated, the column collapse and so is the structure.
Depending how the structure falls, there are two types of implosion:
Falling like a tree: In this type of implosion, the building is made to fall like a tree to the sideward. This is the commonly used type of implosion. When free space is available besides the building, this type of demolition is prescribed.
Falling into its own footprint:
When the free spaces are not available around the building and the structure around the building are to be protected. This type of demolition is used. In this type of demolition, explosives are set in the floor below the middle part of the building.
As the explosions are detonated, the upper part of building destroys and falls upon the lower building. Due to the heavy load and force the lower part of the building also collapses and falls on its own footprint.