There are two types of Demolition employed for buildings and structures
Non-explosive or controlled demolition
Implosion is the Demolition of a building by explosives. With the removal of the foundations, the structure will collapse. This method is used mainly for large factories and power stations. Most Demolition in Towns and Cities is carried out by conventional means.
This method involves the main supports of a building, including column’s, beams and slab fixed with explosives. Once the explosives detonate, the building will collapse.
Depending on how the structure falls, there are two types of implosion:
The implosion makes the building fall like a tree sideways and is the most common method of implosion. Where the building has sufficient area around it available besides the building, this type of Demolition is preferred.
If there is free space available on the left side of the building the explosives are placed on the lower level of the building on the left-hand-side columns. As the explosives detonate, the columns bursts and the building will fall towards the left-hand side. Cables are tied to the building and control the direction of the fall.
When there is limited space around the building, this type of Demolition selected. Explosives are placed into the floor below the middle part of the building.
These explosives are substantial as the explosion must demolish the building at once. It is a series of blasts, one followed by another. Then the building falls towards the first blasted part.
When the charges detonate, the upper part of building implodes and falls onto the lower building. The heavy load and force the lower part of the building also collapses and falls on its footprint.