Single layer grids |
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Strictly
speaking, structural single layer grids are comprised of rigidly fixed
members. |
Examples
include the structural framework, or mullion, of glazed curtain walls,
false |
ceilings, room partitions, etc. A broader definition includes
grids whose members are |
connected together with flexible joints such as nets or screens. |
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 |
Fig. 225 - Structural |
 |
single layer grids |
|
◄ a) fixed joints |
(glazed curtain wall) |
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b) flexible joints ► |
(chair seating) |
(scale visualization models) |
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Two or
more single layer grids can be stacked on top of each other in a parallel,
multi- |
layer
structure to stiffen the layers against loads applied perpendicular to
their plane. The |
layers
are joined together by struts, or web elements, that span from the joints,
or hubs, of |
one
layer to the joints of the adjacent layer(s). The resulting layered
structure can be |
classified as a double layer grid or a lattice depending on the relative
orientation of the |
layers
to each other. |
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Double layer grids |
. |
If the
grid pattern of one layer is superimposed on top of the pattern of the
other, adjacent |
layer(s)
so that the members and joints overlay, or eclipse, each other, the
resulting grid |
structure is said to be double layered. Fig. 226 below shows models of double layer grids |
formed
from a pair of two-way diagonal grids like the one shown in
Fig. 224 previously. In |
figure
b) the webbing forms oblique angles with the layers so it is called a
trussed double |
layer
grid. Examples of double layered grids include grates, catwalks, bridge decks, etc. |
. |
 |
 |
 |
click image to enlarge |
a) double layer grid catwalk |
b) truss grid portico |
. |
Fig. 226 - Two-way diagonal double layer grids
(scale visualization models) |
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to Knowhere |
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Page 133
- Building stability - Single and double layer grids |
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