PROJECT MANAGEMENT OF A DEMOLITION PROJECT USING IMPLOTION TECHNIQUE
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.
Even though each demolition is a unique event, it is possible to conceive of the destruction project as a generic set of processes that culminates in the complete dissolution of an existing structure. It is recognized that destruction can take many forms, including a form that that may even include renovation or upgrading of an existing edifice. The focus in this presentation is not on these “partial” destructions. Rather, the emphasis is placed on “total” destruction in which the existing structure is demolished or “taken to the ground” by, say, wrecking ball or implosion techniques.
The Implosion Alternative
Why implode? As might be expected, implosion is the preferred demolition technique when it represents the safest and/or most economical approach in a given situation. For fairly obvious reasons, it is the favored approach in demolishing large buildings comprised of many floors and levels and/or buildings located in congested built-up areas. Once considered to be a rather rare approach to demolition due to its perceived risky nature, the technology has been now developed to the point where unfortunate incidents are the exception rather than the rule. Consequently, customer and community acceptance of implosion as a viable destruction technique is somewhat widespread at the moment. This is not to say that there are not unfavorable outcomes. As will be shown later, things do not always go as planned.
Implosion is a technique for achieving a controlled progressive collapse of a structure. Although explosives are used in the process, the building itself is not “blown up” as many people seem to think. Rather, small quantities of explosives (perhaps weighing only a few ounces each) are strategically placed in a way that “removes” structural supports. As these supports are removed, the force of gravity takes over and the building falls to the ground in an anticipated way (hopefully).
The number and the placement of the charges depend on a number of factors assessed by the demolition team. Included among these factors are age and condition of the building, its size and design (configuration), and construction materials/technology used. A typical large structure might require several thousand separate explosive charges to bring it down, but some may require only several hundred. Once the charges are detonated, the buildings crumble in a matter of seconds.
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.
The usual project management processes apply. The planning, implementation, and termination stages of implosion projects are easily identified. The major difference between construction and destruction projects is, of course, that the implementation stage of the latter is quite short. The implosion itself is only one part of implementation. Also involved in that stage would be the transport (and storage) of the explosives, obtainment of the necessary permits and local support personnel, determination of the optimal explosive configuration (including testing), physical placement of the explosives, conduct of a neighborhood preparedness program, delivery of media and citizen awareness campaigns, and enforcement of follow-up cleanup activities. Since some of these tasks can be conducted in parallel, the elapsed time for all of these activities to take place could be as little as a few months for an experienced demolition contractor.
Preparatory to the implosion itself, the building must be prepared and a risk mitigation plan must be put into effect. In addition to readying the building structurally for what is to come (by weakening some of infrastructure and removing walls on lower levels), the project team “strips” the building of components that may lead to undesirable consequences as far as air pollution and public heath are concerned. Such environmental remediation, particularly as it relates to asbestos and lead components, is required by federal and state laws. As an example, demolitions must adhere to United States Environmental Protection Agency regulations embodied in its National Emissions Standards for Hazardous Air Pollutants (NESHAP) code.
During the implosion that lasts only seconds, considerable threats to human life and damages to property could potentially be at stake unless every effort is made mitigate these potential risks. (Actually, the longer does the implosion last, the greater are the risks.)
Adequate controls and safeguards need to be in place so that these “external effects” are minimized. These controls typically require the efforts of not only the project team, but also inputs from the community and its government units as well (public officials, police and fire departments, hazardous waste units, and so forth). Substantial community resource inputs are, in fact, necessary at every step in the process as permits must be given in the early stages, safety and environmental concerns musts be addressed, crowds and traffic must be controlled, crimes and fires must be prevented, and cleanups must be monitored and inspected.
Undesirable but unpreventable physical outputs of the implosion process include dust and debris. These entities must be controlled. Dust spews forth in dense clouds in a way determined by the pattern of the building’s collapse and the prevailing wind. Mountains of debris pile up and must be removed, after which the area and its surroundings must be cleaned up and restored. When the Seattle Kingdome was imploded recently, dust clouds spread out all over downtown Seattle and, at the site, a pile of rubble emerged that was over 12 feet high in places. Removal and cleanup of that debris will take up to four months of effort by the contractors.
Interestingly, noise and vibrations levels of implosions generally do not cause unusual problems, as they have been shown to be usually within limits allowable by law.
Finally, undesirable but preventable physical consequences of implosions concern damages to nearby properties as well as to, possibly, life and limb of demolition workers, residential and business neighbors, and even onlookers. Even though vibration levels do not generally cause problems, they could do so in certain instances. Vibrations from the implosion have the potential for weakening and damaging nearby structures as well as community infrastructure such as roads, sidewalks, streetlights, and utility pipelines. Windows in nearby buildings may crack or shatter. Flying debris could presumably do great harm not only to buildings but also to people who may be injured by such fallout. The management plan needs to incorporate ways of mitigating all of these very important risks.
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.
Given the nature of the potential risks, the demolition sector has had a rather remarkable track record since data have been recorded. It is rare to hear about even a single injury or fatality associated with the implosion of even the largest structures and complexes, although such outcomes do occur occasionally. For example, within the last decade, the attempted explosive demolition of the Royal Canberra Hospital in Canberra, Australia, went awry, causing extensive human harm and bodily injury. Such drastic outcomes are the exception rather than the rule. (Interestingly, it is difficult to procure detailed data on injuries and fatalities in this industry, and the collection and analysis of such data is a project that I happen to be working on at the moment.)
We are ECG, we are safety first.
This field definitely needs some expert hands and skill. So, have you decided on what type of project you need? Make sure you research on this for a while before coming up with a decision.
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