Civil Engineering Reference
In-Depth Information
Figure 10.5
Mean pressure coefficients on an
arched-roof building—0° (rise/span=0.2).
As for high-pitch gable roofs (Figure 8.6) there is a region of positive pressure on the
windward side of the roof.
The effect of increasing length/span ratio is to increase the magnitude of both the
positive and negative pressures in the central part of the building as the flow becomes
more two dimensional. Increasing wall height to rise ratio
(h
e
/R)
produces more negative
values of external pressure coefficient on the roof, side walls and leeward wall (Paterson
and Holmes, 1993).
For wind directions parallel to the axis of the arch, arched roofs are aerodynamically
flat, with similar pressure distributions as gable roofs, for the same wind direction.
Domed roofs have similar pressure distributions as those on arched roofs, of the same
rise/span ratio, for a wind direction normal to the axis.
Values of pressure coefficients for arched and domed buildings, specified in several
wind loading codes and standards, are discussed in Chapter 15.
