shadow effect for wind loads per asce 7

huangyhg

shadow effect for wind loads per asce 7?
i am designing an unusually-shaped shade structure comprising a cable-stayed, lattice-type  canopy (picture regularly spaced joists joined by continuous transverse elements on top) inclined about 10 degrees from horizontal. it's similar to a mono-pitched roof structure, but it's suspended from a single row of columns that are laid out along an arc, with the lattice joists splayed radially along the same arc.
i think it might be unconservative to analyze the lattice canopy as a covered mono roof, because i'm not sure this would fully account for effects of the wind passing over the tops and bottoms of the (roughly parallel) joists. on the other hand, it would seem drastically conservative to sum the full wind load applied to each of the individual joists, since each of the interior joists are "shadowed" by the preceding one.
short of constructing and testing a model, is anyone aware of a rational treatment of this problem per asce 7-02?
(in case i've described the model too, too horribly, i think the following scenario is roughly analagous:
imagine a series of square posts arranged in a straight line and regularly spaced at, say, 2.5 diameters, with the wind blowing parallel to the line of the posts. how would i estimate the wind loading on one of the interior posts?)
thanks in advance!
-geostructor