Frag Out! Magazine
Issue link: https://fragout.uberflip.com/i/1532587
On one hand categorization of protective structures remains essential. However, the resistance levels assumed for civil defense shelters and command posts must account for advances in modern weaponry and its direct impact on structures. Since the mid-1980s, the quantity, availability, accuracy, and destructive power of precision weapons have increased dramatically. These weapons are now the primary threat to protective structures. Thus, when defining protective structure requirements, conventional weapons must be considered, particularly for high-capacity civil defense shelters and command posts for authorities at all levels. For example, the now-defunct 2018 Guidelines of the Chief of Civil Defense for Procedural Framework Tied to Protective Construction Resources issued on December 4th 2018, did not require protective structures to be resistant to specific types of attacks. As a result, it was possible to design a civil defense shelter for 1,000 people with a large surface area and a 40 cm thick ceiling, the same thickness as a small backyard shelter. A backyard shelter, being small (approximately 20–50 m²), has a lower probability of being directly hit. However, a shelter for 1,000 people on a single floor would require a built-up area of around 1,200–1,300 m². This significantly increases the risk of the thin ceiling being penetrated by artillery shells or other weapons. The same applies to command posts, which are primary targets for direct strikes due to their function. Thus, both large civil defense shelters, and fortified command posts must include resistance to direct hits from specified weapons in their technical requirements. How should we approach defining protection levels and their inclusion in normative regulations? Determining structural resistance to direct impacts is not a simple task - the readers shall be made aware of that. Most professionals authorized to design such structures do not have the expertise to calculate it. ANALYSIS