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Rigid body
B
Temporary
rigid truss
A
Cable
Cable
Roller height
Rigid truss
Rigid body
Pylon
(a)
Cable intersection
Cable
Cable
Cable
Rigid body
C
Rigid truss or body
D
Joint or rigid
connection
Pylon
Rigid body or
rigid truss
Splay saddle
center
Cable
Anchor point
(b)
(c)
Figure 12.16
Model of saddles. (a) Complicate model incorporating saddle jacking.
(b) Simple model for certain types of analysis. (c) Splay saddle model.
flexible splay saddle as shown Figure 12.7 is used, the splay saddle column
will be fixed at the bottom and the true stiffness of the column will be used.
If any analysis is targeting the establishment of the initial state (zero-
stress state) according to the design plan, the constraints of displacements
at cable ends A, B, C, and D should be applied during large displacement
iterations as discussed in Section 12.3.5.
12.5 3d iLLuStrated exampLe of cheSapeake
Bay SuSpenSion Bridge, maryLand
The main shipping-channel bridges of Chesapeake Bay Bridge, Maryland,
1952, also known as Bay Bridge, are suspension bridges where the east-
bound bridge has a main span of 487.68 m and two 205.74-m long sus-
pended side spans. The tower is 107.7 m high, and the truss stiffened girder
passes through it at about its center (Figure 12.1) (Wang and Fu 2012).
The purpose of the analyses is the cost allocation study, which tries to
reveal the contribution to stresses on main components by each designated
live loads. The analysis type is linear with only initial stress considered, and
the geometry configuration as planned is used as the initial state for dead
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