Project Destruction Management

.Project management has its roots in the construction industry, and construction projects of all kinds continue to play a significant role in the profession. The process of building an office tower, school, or stadium “from the ground up” is well entrenched in the folklore of project management, as these types of projects have been examined and dissected thoroughly in the literature over the years. It is fair to say that the generic construction process is well understood by now. But, at some point in time, many of the structures that we have built must be replaced or eliminated. At that juncture, we destruct what we have taken so much time to construct before. While the basic processes that govern the conduct of a construction project are well known, not much has been written about the counterpart destruction activity, at least as far as management is concerned.

The implosion process described above is only one component of the overall demolition project. In fact, since implosion is a rather specialized art performed by only a handful of companies in this country (for large projects), it is typically done on a subcontract basis under a general contractor. That is, implosion services would normally be considered as a procurement by the general contractor. Implosion services do not come cheap, and can easily represent up to more than half of the overall project costs.

As one might expect, the risk-mitigation measures for implosion projects are rather extensive. Nobody wants to deal with the prospect of multimillion-dollar insurance claims against the project. It all starts with the transport and storage of the explosives. Trucks carrying several thousand pounds of explosives over state lines are easily noticed. Federal, state, and local statutes obviously heavily regulate such transport. Designated “safe routes” are utilized to avoid densely populated areas. As the explosives are transported to what might be a site in or near an urban area, fire department officials for the final leg of the journey typically escort the trucks. Nothing is left to chance, including storage of the explosive materials. The National Fire Protection Association (NFPA) regulates storage of explosives. Iron chambers surrounded by earthen barriers serve as holding devices. These chambers are strategically located to minimize the chance that unintended ignition would cause damage to nearby structures. They are placed on 24-hour guard by security officials.

In the preparatory phase, every effort is made to insure that the demolition will proceed in a predictable way once the charges are detonated. Blueprints of the building are studied, and where there are no blueprints, some may be manufactured. Examination and documentation of the types of building materials used, the condition of the building, and placement of the load-bearing beams and columns are undertaken. It is typical for all stairwells to be cut away, and where there are adjoining buildings, for them to be physically separated to the extent possible. In some situations, steel cables may be attached for possible use in pulling the building in a certain way once it starts to fall. And, in addition to inserting explosives in holes drilled into columns, some may be wrapped around structural support columns that have been designated as critical to a successful result.

The environmentally related pre-implosion operations for asbestos and lead have been mentioned already. This can be a very costly undertaking for older buildings.

A test series of blasts is always desirable, and usually employed unless unique conditions preclude this activity. Among other things, a test blast indicates how far debris may stray from the building when the major event occurs. In cases where the debris may travel a distance that is considered excessive, openings of the building may be covered to contain the flying rubble, or chain-link fence materials may be used to keep debris under control.

In the implementation or execution stage, worker protection and crowd control are of paramount importance. The demolition team, working with community and government officials, defines what is known as a blast or safety perimeter. Think of this as a no-trespassing zone. This is an area that is heavily controlled to insure the maximum safety for workers and citizens. Actually, two perimeters would be defined. The first or primary perimeter would exclude anyone other than personnel essential to the conduct of the blasting operation. Obviously, pedestrian and vehicle traffic is re-routed. The outer boundary of this perimeter may be anywhere from 500 to 1,000 feet away from the building site. The secondary perimeter beyond would allow the presence of pedestrians and vehicles. At this perimeter’s edge would be the area roped off for onlookers and curiosity seekers.

To minimize neighborhood impacts on property and human health, residents and businesses situated within the blast perimeter are notified about the timing of the implosion, and, as a precaution, are asked to close (but not necessarily board up) all windows, shut off all air intake devices (e.g., air conditioners), and provide covers over any vents through which dust may enter their premises. In rare instances, the demolition contractor may provide special protection for neighboring properties. This may involve the physical wrapping of buildings in special kind of plastic or erecting protective barriers of some type.

Prior to detonating the charges, the fire department may be asked to soak down lower levels of the building in order to achieve dust control, particularly on days when the prevailing winds introduce uncertainty into the dust cloud’s ultimate destination.