Masonry structuresFig. 5.40 Action of tall single-storey building in response
to wind loading. The high walls span vertically between the
foundation and the wind girder at roof level, which trans-
mits the load to the end walls. The side walls here act as
propped cantilevers and can be subjected to high levels of
bending moment.
bending loads. Typical dimensions for all of
these types of wall are given in Table 5.3.
5.3.6 Provision for accidental damage
There are certain types of very high intensity
load whose occurrence is so rare that it is not
economic to make walls strong enough to
resist them. Examples are the collision of a
heavy vehicle with a building or an explosion
which results from the ignition of leaking gas.
Because buildings are not sufficiently strong to
resist these, damage or partial collapse results
Fig. 5.41 Various strategies can be adopted to give the
walls of tall single-storey buildings sufficient bending
strength to resist out-of-plane load due to wind.
(a) Buttressed cavity wall (suitable for heights up to 3 m).
(b) Fin wall (suitable for heights up to 5 m).
(c) Diaphragm wall (suitable for heights up to 10 m).if they occur, but the risk of this happening is
taken to be sufficiently low to be acceptable. It
is necessary, however, that the stability of the
whole building should not be endangered if a
single structural element, such as a wall or an
area of floor, should collapse due to the occur-
rence of a freak load. In other words, a progres-
sive collapse should not result from an
incident in which a part of the building only is
directly involved.
The UK Building Regulations require that
structures should be designed so that progres- 177(a)(b) (c)