Offshore Structure Loads and Strength - Offshore Structures: Design, Construction and Maintenance - page 29

TABLE 2.6 Minimum Uniform Loads from Industrial Practices

Uniform Load, kN/m 2 (Ib/ft 2 ) Platform Deck

Helideck

Without helicopter 14 (350)

With Bell 212 2 (40)

Mezzanine deck 12 (250)

Production deck 17 (350)

Access platforms 12 (250)

Stairs/walkways 4.7 (100)

Open area used in conjunction with the
equipment operating and piping loads for
operating and storm conditions

2.4 (50)

TABLE 2.7 Impact Load Factor

Load Direction

Structural Item Vertical Horizontal

Rated load of cranes 100% 100%

Support of light machinery 20% 0%

Support of reciprocating machinery 50% 50%

Boat landings 200 kips (890 kN) 200 kips (890 kN)

2.2.3 Impact Load
For structural components carrying live loads that could face impact, the live
load must be increased to account for the impact effect, as shown in Table 2.7 .

2.2.4 Design for Serviceability Limit State
The serviceability of the topside structures can be affected by excessive relative
displacement or vibration in vertical or horizontal directions. Limits for either
can be dictated by the following:

Discomfort to personnel. ●

Integrity and operability of equipment or connected pipework. ●

Limits to control deflection of supported structures, such as flare structures.

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