Page 127 - Marine Structural Design

Chapter 6 OjJshore Structural Analysis 103

6.2.2 Design Basis
The Design Basic document lists the basis criteria relevant to the structure and should include
the following:
Unit Description and Main Dimensions
A summary describing the structure includes:
A general description of the structure, including the main dimensions and draughtlwater
depth
Main structural drawings
Service and design lives
Location of the structure, if fixed
Specification of the system of units employed

Environmental design criteria, including all relevant conditions, such as wind, wave,
current, snow, ice and earthquake description with 10E-1, 10E-2, and 10E-4 annual
probability occurrence.
Soillfoundation criteria for design of fixed structures, mooringlanchoring, pipelines and
risers.
Design temperatures
Stability and Compartmentalization
Stability and compartmentalization design criteria for relevant conditions include:
External and internal watertight integrity
Boundary conditions including interfaces With other structures or foundation conditions
Lightweight breakdown report
Design load cases and global mass distribution
Damage condition
Materials and Welding
Design criteria for materials and welding include:
Yield and ultimate tensile strength
Corrosion allowances to be taken
Corrosion Protection (CP) systems or coatings
Material flexibility and avoidance of brittle fracture
Crack growth properties
Weld specification and fatigue classification