Civil Engineering Reference
In-Depth Information
7.6.10 AISC Historical Background
According to
Brockenbrough (2003)
, the welding specifications based on AISC
have been changed as shown in
Table 7.5
.
7.6.11 Pile Design Historical Background
Pile design depends on the configuration of the platform, the water depth and
the construction method on site at the time of execution.
Because water depth has the most effect on pile design,
Figure 7.1
presents
the platform numbers in the North Sea before 1994, and the figure shows how
the number of platforms with a water depth over 100 m (300 ft) increased
rapidly after 1974.
From
Tables 7.2 and 7.3
, the effect of the limiting friction and end-bearing
values can be seen at around 35 m for both the first and fifteenth editions for
API RP2A. For compressive capacity, there is very little difference between
the ultimate capacities predicted by the first edition and those predicted by the
fifteenth edition; the only real change for dense sand is in the value of the lateral
Historical AISC Allowable Stresses (N/mm
2
) for Weld in ASD
TABLE 7.5
Fillet
Weld
Shear
Steels and Welding
Materials
Year
Tension
Compression
1934
A7/A9 steel
78
89.6
103.4
1939
A7/A9 steel
78
89.6
124.1
1946
A7/A9 steel: 60XX electrodes 93.8
137.9
137.9
1961,
1963
All steels: 60XX electrodes or
subarc grade SAW-1.
A7 and A373 steels: 70XX or
subarc grade SAW-2.
A36, A42, A441 steels: 70XX
or subarc grade SAW-2.
93.8
Same as member
all cases
Same as member
all cases
93.8
108.9
All steels and weld processes
1
1969
0.3
F
uw
Same as member
all cases
Same as member
all cases
1989
No significant changes
0.3
F
uw
Same as member
all cases
Same as member
all cases
Note that, for butt weld, the shear strength is 93 N/mm
2
Electrodes and matching base metals are defined. Allowable shear stress is 0.30 times nominal tensile
strength of weld metal. 0.30
F
uw
in supplement 3, 1974, permitted weld metal with a strength level
equal to or less than matching base metal, except for tension members.
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