Hi all,
I'm a bit confused to generate load case for riser stress analysis. if there are wave and earthquake load not in uni direction. I use B31.8 chapter VIII as a code stress check. to simplify the situation let consider wave load only, here are the load case what i proposed:
Load Case:
L1 WW+HP (HYD)
L2 W +P1+T1 (OPE)
L3 W +P2+T2 (OPE)
L4 W +P1+T1+WAV1 (OPE)
L5 W +P1+T1- WAV1 (OPE)
L6 W +P1+T1+WAV2 (OPE)
L7 W +P1+T1- WAV2 (OPE)
L8 W+P1 (SUS)
L9 W+P2 (SUS)
L10 T1 (EXP)
L11 T2 (EXP)
L12 L2-L8 (note 1) (EXP)*
L13 L3-L9 (note 1) (EXP)*
L14 L2-L10 (SUS)*
L15 L3-L11 (SUS)*
L16 L4-L2 (OCC)*
L17 L5-L2 (OCC)*
L18 L6-L2 (OCC)*
L19 L7-L2 (OCC)*
L20 L16+L17+L18+L19 (OCC)****
L21 L8+L20 (OCC)***
L22 L2+L3 (OPE)****
L23 L22+L20 (OPE)***

Note:
1. For ASME B 31.8 Ch. VIII no stresses check for EXP load cases.
* Use algebraic combination method under the Load Case Options tab.
** Use SRSS combination method under the Load Case Options tab.
*** Use ABS or Scalar combination method under the Load Case Options tab.
**** Use Maximum combination method under the Load Case Options tab.

but in hydrotest case it should be consider with 1 years wave loading. so I add WAV3 and WAV4 as 1 years wave load then:

L24 WW +HP+WAV3 (HYD)
L25 WW +HP- WAV3 (HYD)
L26 WW +HP+WAV4 (HYD)
L27 WW +HP - WAV4 (HYD)
L28 L24+L25+L26+L27 (HYD)****

is my strategy correct?, i dont used OCC on hydrotest case because the pipe is not corroded.

thanks in advance.