Structural Design for Architecture82
Fig. 3.37 A Mero space frame, supported around its
perimeter, acts as the roof structure in this single-storey
building. Note the vertical-plane diagonal bracing
elements which must be provided in each external wall of
the building. The fully triangulated space framework acts
as horizontal-plane bracing. [Photo: BICC]is required, and space frames can even be given
an irregular overall form so long as the internal
geometry is fully triangulated.
One of the advantages of the space frame is
that the individual elements are small and
light. The parts can therefore be easily trans-
ported to the site and no large equipment is
required for erection; often the structure can
be assembled at ground level, by bolting or
welding, and subsequently lifted by a jacking
process into its final position. This greatly
simplifies the construction.
The principal disadvantage of the space
frame is its complexity. In particular, the high
degree of geometric complexity makes difficult
the design and manufacture of the joints, and
the high degree of statical indeterminacy
aggravates this problem by requiring that
components be manufactured to small toler-
ances so that the 'lack-of-fit'^12 is minimised.
The difficulties which are associated with
construction can be reduced if a high degree of
standardisation is adopted and the space
frame is a type of structure which can be most
economically produced in the form of a propri-
etary system. A number of these are currently
available and they exploit the potentially high
structural efficiency of the space-frame config-
uration while at the same time allowing a
reasonable level of cost to be achieved through
the standardisation of components and by
means of the economies of production-line
manufacture (Figs 3.38 to 3.41).
Standardisation reduces the structural
12 See Macdonald, Structure and Architecture, Appendix 3 for
an explanation of the 'lack-of-fit' problem.