EFFECTS OF EXPLOSIONS
SCOPE AND RELATED CRITERIA.
The topics covered in this section include:
Safety Factor Introduced to Weight of Explosives.
Blast Pressure Output.
Partially Vented Explosions.
Fully Vented Explosions.
Airblast From Underwater Explosions
External Blast Loads on Structures.
Pressure Increase Within Structure.
10. Primary Fragments.
The topics listed above are dealt with in brief in this section.
More detailed information is provided in the texts and documents
referenced in this manual. Design examples are provided in paragraph 12
to help the user understand the procedures outlined in this section.
b. Related Criteria. In blast resistant design, the principal effects
of the explosive output to be considered are blast pressures and primary
fragments. Usually, the blast pressures are the governing factor in the
determination of the structure's response.
SAFETY FACTOR AND ACCURACY.
a. Simplifications in the Development of Design Procedures. Certain
simplifications have been made in the development of the design procedures
presented in this manual. As a result, an analysis of a structure using
these procedures will generally result in a conservative estimate of the
structure's capacity and, consequently, structures designed using these
procedures will generally be adequate for the blast load exceeding the
assumed loading conditions.
b. Modification of Charge Weight. Certain unknown factors can result
in an overestimate of the protective structure's capability to resist the
effects of an explosion. These factors, reflections of the shock waves,
structural response, construction methods, quality of construction
materials, workmanship, etc., vary for each facility design. To
compensate for weaknesses resulting from these factors, it is recommended
that the "effective charge weight" or the actual charge weight, depending
upon the method used to determine the TNT equivalent, be increased by 20
percent for design purposes. Modification of