Civil Engineering Reference
In-Depth Information
TABLE 8.16
Inspection History
Years Since
Inspection
Level of Last Inspection
Level II
Level III
Level IV
1
0
0
0
2
2
0
0
3
4
2
1
4
8
5
3
5
9
7
5
6
9
8
6
7
10
9
8
8
10
10
9
9
10
10
10
For each inspection level, calculate tabulated scores,
SII
for Level II,
SIII
for Level III and
SIV
for
Level IV. Score = min (
SII
,
SIII
,
SIV
)
For each inspection Level II through III, apply the following formula:
The years since inspection
=
min
ð
9, this year
−
inspection year
Þ
The last inspection factor does not interact with any other factors, as it is totally
independent of the design or the condition of the platform; it is a matter of operation
and the maintenance plan, which depend mainly on the budget and the existing
robust plan. This factor highlights the necessity of different levels of inspection
in order to eliminate or lower the perceived risk factors of a platform.
Remaining Wall
Similar to damaged and flooded members, the number of corroded members has
a major effect. However, in this factor, the amount of corrosion is also impor-
tant (for damaged or flooded members, the amount of damage is not
considered).
In terms of remaining wall thickness, it was felt that at least a 20% decrease
is required to affect strength. Corrosion is typically localized on the member
and this has been accounted for in the approximation, noting that the score
would be higher if the entire member were corroded. Corrosion above 50%
was considered extreme and was assigned the highest score.
The extent of corrosion refers to the number of members affected. The quan-
titative calculation for this factor follows the same logic as for damaged and
flooded members. Note that, in this case, the score is inverted compared to
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