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DOD Protective Design Manuals Have Wide Application PDF

DOD Protective Design Manuals Have Wide Application - PDF (Page 17)
Patrick Lindsey, PE, Protective Design Center, US Army Corps of Engineers, Omaha, NE

Factors such as site selection, building location of the site, use of fences and clear space, as well as vegetation and structural reinforcements are all critical to protecting a building and its occupants from various threats. Incorporating protection into a facility's design is the best way to achieve a desired level of protection at a reasonable cost. Patrick Lindsey of the Protective Design Center summarizes many of the key features and considerations to be accounted for, and introduces the DOD resources available.

The AMPTIAC Quarterly

Volume 6, Number 4

DOD Protective Design Manuals Have Wide Application

Introduction

Many manuals are available within the DOD to aid engineers in the design of facilities subjected to blast loadings from bombs. Facility design in consideration of exterior blast loadings starts with locating a site that is adequate for the facility and level of protection required. The design basis threat (as defined by the installation master planning team) identifies the weapons, tools and tactics that could be used in an attack against the facility. The site or master planners then review the site plan and the design basis threat to determine if the amount of standoff distance that is available can provide a proper level of protection. The planners will then incorporate the use of controlled and non-controlled perimeters, locate appropriate exclusion or non-exclusion zones, define the standoff distances, and identify facility clear zones. They will also locate the facility's entry control points for vehicles and personnel. Should the site be inadequate for a structure built with standard construction techniques, then blast loadings will need to be accounted for to give the facility the same level of protection at the reduced standoff distance.

Background History of Standards

Military Hardened Structures Progression Since the invention of dynamite by Alfred Nobel in 1866, blast effects on structures have been observed. In 1870, Rankine and Hugoniot published their analytical solution to normal shocks in an ideal gas and these relationships have formed the foundation for studying gas dynamics and the interaction of shock waves with structures. It is well known that internal blasts are more damaging than exterior blast effects as the shock and gas pressure combine to act on the structure.

In the last 50 years, the engineering units within the Military developed many mathematical models to capture the structural interaction with blast waves. After World War II, these models started to show development when damage levels for masonry structures we re correlated to crater size, crater location, and explosive weights used in bombing runs. Damage level was a measure of the amount of structure remaining based on the blast pressure and impulse the structure experienced from those bombs. From those early days of the 1950's other observations were noted that relate the many blast parameters to scaling laws, thus making it easy for engineers to develop models for predicting categories of damage based on: weight of explosive, range, and type of structure. The 1950's were also the beginning of the nuclear age, and many design ideas were developed during this era. A lot of the bunker mentality commonly associated with explosive effects came from this time period.

Anybody who has handled explosives knows the dangers associated with that endeavor, as many accidents have occurred as a result of their handling. A vast amount of knowledge was acquired from accident investigations of catastrophic events. To protect personnel, a Tri-Service group from the Army, Navy and Air Force was formed to develop a manual to give engineers a procedure that lets them design "Structures to Resist the Effects of Accidental Explosions" (commonly known as technical manual TM 5-1300). The primary purpose of the manual is to present methods for protective construction used in facilities for the development, testing, production, storage, maintenance, modification, inspection, demilitarization, and disposal of explosive materials. This manual was used as the standard for explosive effects for about thirty years. By using this manual, engineers could design structures to resist the effects of blast waves and fragments preventing the propagation of explosive effects from one structure to the next, or to prevent the mass detonation of explosives and provide protection to personnel and valuable equipment. Instrumental to this approach was a well-developed understanding of:

  • the blast load parameters
  • the response of structures to blast loads
  • how to establish proper details for construction to develop the proper structural response
  • establishing guidelines for siting explosives facilities.

Technical manual TM 5-855-1, "Fundamentals of Protective Design for Conventional Weapons" also came out of the post- World War II era. While this manual is dedicated to the design of structures to resist conventional weapons, during the 1970's great advances were made in the area of numerical modeling of nuclear weapon effects. These include the effects of dynamic response of aboveground, and belowground structures to airblast, blast-induced ground shock, cratering, and the response of various materials to these effects. These modeling techniques were then applied to the conventional weapons arena and the manual has been updated several times since its original printing.

This manual and TM 5-1300 deal with primarily concrete and steel structures, but not everybody works in those types of structures. Additional work has produced more data on how conventional construction responds to blast loads and that data has been incorporated into the new design guidance.

After the Marine barracks bombing in Beirut, Lebanon in 1983, the DOD looked for a group to develop procedures that could be implemented to prevent this type of incident from recurring. The Army established the Corps of Engineers Protective Design Center to take on this mission and its main purpose was to provide physical security and antiterrorism protection to military assets. The first document created by this group was called the Security Engineering Manual, which became the TM 5-853 series of manuals on security engineering. Much of the blast and fragment technology developed for TM 5-1300 and TM 5-855-1 had direct application to the area of security engineering. Within this series of manuals, aggressors, weapons, tools and explosives are defined to develop a design basis threat against specific assets. With this information protective measures are designed to counter these threats and protect the defined assets.

The physical security portion is that part of security concerned with physical measures designed to safeguard personnel; prevent or delay unauthorized access to equipment, installations, material, and documents; and to safeguard against espionage, damage, and theft. Prior to this period, many of the regulations were not interrelated or tied to design procedures, and at times it was difficult to determine what level of protection was being provided for an asset. This manual brought threats and protective measures together as a security engineering design procedure, balancing the design basis threat against the level of protection.

The antiterrorism aspects of facility design are the defensive measures used to reduce the vulnerability of individuals and property to terrorist attacks and often include a limited response and containment of the aggressor by local military forces, or a response force. Therefore, security engineering is the process of identifying practical, risk-managed short and long-term solutions to reduce and/or mitigate dynamic manmade hazards by integrating multiple factors, including construction, equipment, manpower, and procedures.

Continue reading in AMPTIAC Special Issue Quarterly - PDF 68 Pages.

Military Hardened Structures Progression

Application of DOD Manuals to Antiterrorism

Security Engineering Definitions
Controlled Perimeter
Standoff Distance
Level of Protection
Nonexclusive Zones
Clear Zones
Facility Clustering
Lines of Sight
Minimum Measures

Entry Control Points
Approach Road
Visitor and Truck Access Control Center
Entry Control Point
Gates and Barriers

Site Planning
Vantage Points
Minimum Standoff Distances
Unobstructed Space
Railroad Location

Building Layout
Parking Beneath Buildings
Drive-up / Drop Off
Superstructure
Building Location
Asset Location

Also see: Designing Blast Hardened Structures For Military & Civilian Use - PDF, Page 53.