Civil Engineering Reference
In-Depth Information
361′ 6″
428′ 9″
490′ 0″
428′ 9″
490′ 0″
STA .929
+ 44.589
EL. 169.77
0
STA
.934 + 34.5
87
EL. 16
8.300
Typical truss arrangement
see detail below
ST
A .921 + 48
.343
EL.
172.159
STA .92
5 + 15.841
EL. 171.0
56
STA .938 + 6
3.335
EL
. 167.014
E
E
F
E
F
ξ Pin
EL. 93.300
ξ Pin
EL. 96.056
ξ Pin
EL. 94.770
ξ Pin
ξ Pin
EL. 92.014
EL. 90.
0
2
4
6
8
10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68
Figure 10.19
Five-span thermal analysis model.
Top-panel
x
deflection
6
4
2
0
1
4
7
10
13
16
19
22
25
28
31
34
37
40
43
46
49
52
55
58
61
64
67
−2
−4
−6
Panel point
Figure 10.20
Top-panel horizontal movement due to temperature rise.
top-panel points where the left-panel points move toward the nega-
tive direction, whereas the right-panel points move toward the positive
direction. Figure 10.21 shows the
y
-movement (i.e., vertical movement)
of the top-panel points where the panel points near supports move
upward, whereas the panel points away from supports move downward.
Noticeably, discontinuity is formed at the expansion joints, which means
there is an angular movement at sliding plate locations. For compari-
son,
x
- and
y
-movements of the bottom-panel points are also plotted on
Figures 10.22 and 10.23, respectively. It is clearly seen that the
x
-move-
ment is much less at the bottom-panel points on the anchor span. This
displacement pattern reveals that the archlike anchor span will bend
up when temperature arises. Because the vertical movements at expan-
sion joints are not even, it is numerically proved that sliding plates as
noticed in the field do not fully bear the stiffened plates on the bottom
as a designed sliding plate system. Gaps are formed between plates, and
sizes of the gaps depend on the temperature. The formation of the gap is
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