ANTI-TERRORISM DESIGN
Reigstad & Associates, Inc

Reigstad & Associates awarded 2 military projects due to anti-terrorism and non-progressive failure expertise.

Bachelor’s Enlisted Quarters Building Naval Construction Battalion Center – Gulfport, MS images courtesy of Studio South Architects, PLLC Stories:  4 Building Area:  80,500 sq. ft. Structure:  Concrete Moment Frame antiterrorism:  Local Collapse Only Approx. Cost:  $12 Million

Technical Training Facility Building Keesler AFB – Biloxi, MS image courtesy of Studio South Architects, PLLC Stories:  4 Building Area:  189,000 sq. ft. Structure:  Steel Moment Frame Antiterrorism:  Local Collapse Only Approx. Cost:  $22.4 Million

We at Reigstad & Associates have a great deal of expertise in the anti-terrorism and non-progressive failure design. Recently, we have incorporated this knowledge in the design of two projects located on military bases in Mississippi. (see above).

Progressive collapse is a term that the engineering community, as well as the public, is all too familiar with lately. Whether it be the Oklahoma City Murrah Federal Building bombing or the New York City World Trade Center attack, the devastating effects of this "chain reaction" type of collapse has concerned us all. Recent design requirements published by the Department of Defense have addressed these concerns and have set forth performance guidelines to prevent catastrophic failures.

An example of progressive collapse would be a multi-story building subjected to the loss of a primary column at a lower level due to an explosion. When the column is removed, the surrounding beams and columns also fail due to increased forces caused by the initial column collapse. By introducing continuity and redundancy into the structure, we are able to alter the building’s behavior to a partial collapse condition (see below). By extensive computer analysis and detailing, we accomplish this strengthening with minimal additional construction cost to the project.

The Department of Defense has released performance requirements even more stringent than the partial collapse concept. They require that, under specially defined loading and modeling conditions, failure be limited to only one level and within only one bay in either direction. This local collapse requirement has been incorporated into our recent military design projects. With careful design and planning we were able to provide the contract award winning solutions for the projects referenced above.

The current building codes do have structural integrity requirements to ensure a minimal amount of redundancy and durability. They do not, however, contain requirements that a building is to remain intact even with the loss of a primary structural element, which could be the case with an explosion inside or next to the building. Should the public be forced to have the financial burden of such stringent design criteria? Are the slim chances of an attack on a building enough to warrant a regulated anti-terrorism code for both public and private buildings? These are questions that will be debated in earnest over the next several years.

Progressive Collapse - Building Code Minimum With loss of a primary structural element (column) chain reaction collapse may occur.	Partial Collapse - Intermediate level With loss of a primary structural element (column) collapse is limited to a reduced area.	Local Collapse - Dept. of Defense Requirement With loss of a primary structural element (column) collapse is limited to a single bay and level.