Diaphragms With End Horizontal Offsets - The Analysis of Irregular Shaped Structures - page 98

F i g u r e 3.9 Single notched diaphragm, analysis in the transverse direction.

The chord is extended into the transfer diaphragm that lies between grid lines 2 and 3,
by means of a longitudinal collector. The transfer diaphragm is supported at the main
diaphragm chord locations at grid lines A and C, making the transfer diaphragm length
of 50 ft and depth of 20 ft. The aspect ratio of the transfer diaphragm is 2.5 : 1. Transverse
collectors are placed along the entire length of the transfer diaphragm at grid lines 2
and 3 to act as chord members for the transfer diaphragm. The sign convention for the
diaphragm sheathing elements is shown at the lower right of the figure.
Construction of the Basic Shear Diagram: The unit shear in the diaphragm must be calculated
before adjusting the shears in the transfer diaphragm area for the influence of the disrupted
chord force. Shear values are required at all collector locations. From Fig. 3.9:

RR wL
1

200 125
2

( )

== = = 12 500 , lbreactionatgrid lines 1 and 4

4

2

R
D

12 500
35

,

v ==

1

=+ 357 1 .plf unit shearatgrid line1

1

VRwx
2

=- = 12 500 , - 200 25 ( ) = 7500 lbshear at grid line2

1