rock blasting
Introduction
Blasting of buildings is the controlled demolition of structures by placing explosive material at strategic points. At the moment of detonation of the explosives, an implosion is created so that a structure collapses in on itself in a matter of seconds, minimizing physical damage to its immediate surroundings. Despite its terminology, the implosion of a structure also includes the demolition of other structures such as bridges, chimneys, towers and tunnels.
The implosion of a construction reduces to seconds a process that could otherwise take months or years by other methods such as progressive collapse using metal rams powered by cranes and cranes for the removal of debris.
The current use of the term "implosion" to refer to the destruction of a building is a misnomer. This term was used in the destruction of Tower 1515, in West Palm Beach, Florida. «What happens is that the use of explosive materials is critical for the structural connections and allowing gravity to collapse it».[1] According to the definition of the RAE's Spanish language dictionary, implosion is «Action of breaking inward with a roar the walls of a cavity whose pressure is lower than the external one».[2].
Terminology
The term implosion of a construction may confuse a person unrelated to the topic, since the technique is not a true implosion process. A true implosion occurs when the difference between the internal and external pressure acting on a given structure is so great that a structure collapses in on itself.
On the other hand, the so-called building implosion techniques do not rely on the difference between internal and external pressure to produce the collapse of the structure. Instead, the technique is based on weakening or eliminating supports or critical structural points such that the building can no longer withstand the force of gravity and falls under its own weight.
Numerous small explosives, strategically placed within the structure, are used to catalyze the collapse. Nitroglycerin, dynamite, or other explosives are used to break reinforced concrete supports. Additionally linear loads are used to cut the steel supports. These explosives are detonated progressively, with short delay periods between each other, throughout the structure. In this way, the explosives on the lower floors initiate the controlled collapse.
A simple structure like a chimney can be prepared for demolition in less than a day. Larger or more complex structures, large buildings, can take up to six months of planning and preparation to remove internal walls and columns, wrap them with fabric and fencing before firing the explosives.