Section 3 Load combinations
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Offshore Units, July 2022 - Part 9 Concrete Unit Structures - Chapter 2 Loads and Load Combinations - Section 3 Load combinations

Section 3 Load combinations

Parent topic: Chapter 2 Loads and Load Combinations

3.1 Load factors and load combinations

3.1.1 The general principles for load combinations for marine service are given in Pt 4, Ch 3, 4.3 Load combinations. Details of all load combinations for use with concrete structures, with the appropriate load factors, are given in Pt 9, Ch 2, 3.1 Load factors and load combinations 3.1.3 for the various limit states.

3.1.2 The design load is usually taken as the characteristic load multiplied by the appropriate load factor. However, for floating structures it is necessary for the load factors to be such that each load combination considered is in equilibrium with regard to applied loads and buoyancy.

3.1.3 In addition to in-service load combinations, the design is to take into account loading conditions on the complete or partially complete structure during construction on a slipway or in a dock, launching, completion afloat, towing to site and anchoring to final position. Local environmental loads, appropriate to the season where applicable, are to be considered. The design for these conditions is to be such that the interim and subsequent compliance of the structure with the permanent design requirements is not impaired.

Table 2.3.1 Load factors and combinations for use with characteristics loads

Load Type ULS SLS FLS PLS Intact PLS Post Damage
(a) (b) Accidental Abnormal
Permanent (P)

1,3

see Note 1

1,0 1,0 1,0 1,0 1,0 1,0
Live (L)

1,3

see Note 1

1,0 1,0 1,0 1,0 1,0 1,0
Deformation (D) 1,0 1,0 1,0 1,0 1,0 1,0 1,0
Pre-stressing (D)

1,1/0,9

see Note 3

1,1/0,9

see Note 3

1,0 1,0 1,0 1,0 1,0

Environmental (E)

see Note 2

0,7 1,3 1,0 1,0 1,0 1,0 1,0
Accidental (A) — — — — 1,0 — —

NOTES

1. These load factors are the minimum allowed and are to be consistent with the selected recognised Concrete Structural Code or Standard. Some Codes or Standards allow reduced factors for well defined hydrostatic loads. Both of these factors are to be 1,0 where this leads to more onerous conditions.

2. Return periods for environmental loads are to satisfy Table 2.2.1 Basis for selection of return periods for environmental loads.

3. Both coefficients are to be used in the analysis.

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