can handle that building collapsing,
without sustaining any damage to
its structure, and without losing the
protective properties, also allowing
the people inside to evacuate. The
former parameter is achieved through
the proper design of walls and ceilings
(type and thickness of the steel
reinforcement, class and thickness of
the concrete, and so on, while the latter
involves the arrangement of spare
escape routes, allowing the "tenants"
to leave, should the main entrances
be cut off. The spare escape routes,
usually offered resilience parameters
equivalent to the shelter that they
were associated with. They are usually
quite a noticeable element that is a
sign, when out and about, suggesting
that a shelter can be found underneath
the given building or structure. The
normative recommendations suggest
that the spare escape routes and the
exits should be located outside the
area, where the building could turn
into a pile of rubble. The formulas used
to calculate that area were evolving,
depending on the studies, the type
of building above the shelter, and the
material that was used to erect that
building. For most of the buildings
erected during the Polish People's
Republic era, that distance was:
R = h/2 + 3 m
ANALYSIS
