Civil Engineering Reference
In-Depth Information
Client brief
Define use/s
Define structural brief
Define implications on design
Delivery of brief through design
Figure 8.1
Consideration process
It is therefore important to consider that during the lifetime
of any hospital building, the initial defined use of the space is
likely to need to change many times and so the ability for that
space to be flexible will be one of the key drivers for structural
solutions for the frame. This may drive the need for an eco-
nomic long (clear) span structure where the small extra cost
associated with such a solution is typically more than offset by
the benefit of improved future flexibility.
The placement of columns within any floorplate is an import-
ant consideration and careful thought must be given to how
this might influence the arrangement of internal division walls
or compartmentalisation of space which could vary greatly
depending upon the use, not just at the outset but in the future.
It is recognised in the medical care field and particularly
in the patient healing and recuperation process that natural
daylight plays a significant role. Buildings designed for ward
use should therefore be shallow in depth so that daylight
can penetrate fully into that space without, for example, the
encumbrance of perimeter downstands restricting the height of
windows, or structure which might hinder the daylight path-
way (see
Figure 8.2
).
To achieve the greatest flexibility, consideration should
therefore firstly be given to the potential for achieving eco-
nomic clear-span space. Spans of up to 15 m may be econom-
ically achieved using steel beams supporting a concrete floor
system on a panel or column bay width of say 3 m or 6 m. Such
a solution could be combined with web openings in the beams
to facilitate services coordination.
In order to provide a flexible design to facilitate potential
occupancy or use changes in the future, generalised live load
categories should be applied to large areas, preferably one cat-
egory to any one floor. For example, designing for a reduced
load (as required by code or use) over a small floor area of a
whole floor requiring a higher load would not be practical or
realistically economic. Such a solution may also limit future
flexibility to change of use.
In hospital buildings, of key importance is consideration of
the structure for limitation of vibration. It will be appreciated
that hospital uses involving sensitive equipment and particu-
larly operating theatres need to be functional within the whole
context of a larger hospital environment. However, such sensi-
tive uses may require limitations to be applied on the perform-
ance of the structure as a whole such that there would be no
residual effect on these functions of use. For example, due to
slab continuity, panels adjacent to any areas specified for sen-
sitive use would duly have to be considered for the effect they
may have, particularly for footfall type vibration causes.
In the UK the strict requirements of the National Health
Service (NHS) are defined in HTM 2045 (NHS 1996) which
provides design criteria in support of BS6472-1:2008. The con-
sideration of vibration, generated typically by footfall but also
by the likes of dynamic plant and equipment, is important not
