There are many reasons why buildings and other structures are demolished. Sometimes, they outlive their usefulness or pose a danger to the public by virtue of structural degradation and must therefore be brought down. In other cases, the structures may have been erected illegally or need to make way for new ones.
Whatever the case, one of the most important considerations in bringing down a structure is the safety of workers undertaking the demolition as well as members of the public.
Haphazard demolition can result in tragedy. Fires, severe injuries, utility services disruption and environmental pollution are some of the unintended consequences of demolitions gone wrong. Demolitions should therefore not be left to anyone. It is important that the contractor selected for the job be experienced in this line of work. They must understand all the possible risks involved and take adequate measures to mitigate them. That said, even the most meticulously planned demolitions do go wrong.
In 2018, a demolition in Denmark went badly wrong when a 174-foot silo collapsed the wrong way and crushed the building next to it. Although no people were in the path of the botched operation, it still demonstrated the risks in demolitions.
Earlier in 2013, a controlled explosive demolition of a storage silo in Australia, went awry when the 100kg of explosives failed to topple the 50-year-old structure. Onlookers were left bewildered when the building only tilted to one side. It was left leaning on that side for more than half an hour before jackhammers were able to weaken the base and get the rest of the job done.
Common risks
Injuries from Debris
Workers and passersby may be injured by falling debris. They must therefore be appropriately geared for the task and any onlookers kept at bay. Certainly, the site must be clear of any persons not involved in the task. It is important to issue an appropriate warning to occupants of buildings near the demolition site.
Premature Collapse
Sometimes, a structure may cave in before workers are at a safe distance. This calls for careful analysis of possible scenarios and full-time situational awareness of the demolition team.
Damage to other Structures
Careful planning has to be undertaken to ensure that the structure collapses in a manner that does not endanger other structures around it. This involves a careful analysis of the direction and manner of collapse.
Disruption of Services
A demolition may result in damaged power cables, water pipes or other infrastructure. Fire outbreak is a real possibility if due care is not taken. This must always be in the minds of those planning the task.
Traffic Disruption
In areas that have vehicular traffic, the safety of motorists and other road users is a principal consideration. Besides, a demolition gone wrong may cause severe disruption of traffic which could have a cascading effect on all nearby roads.
Danger of Hazardous Materials
If the structure contains remnants of hazardous material, improper demolition could result in environmental pollution.
Noise Pollution
Demolitions can be noisy, particularly those carried out using explosives. It is important to inform the public before undertaking the exercise.
A systematic approach to demolition projects is a team effort between many people, who all have responsibilities. These include the structure’s owner, local authorities, engineers, demolition experts and others. It is critical to carefully consider all the risks and be ready for any eventuality.
