Hello, good afternoon everybody.
I'm working in a LNG project where seismic accelerations and seismic anchor movement should be adressed. The applicable code is ASME B31.3, and also NFPA 59A.
My question is related to the load cases and specially to the loads on restraints and equipments.
I have obtaiend U1, U2 and U3 using the criterion (W+D1+T1+P1+U1) - ((W+D1+T1+P1). Then I have combined SRSS of U1+U2+U3 (it is requested by client to consider the 3 accelerations acting simultaneously).
I have done the same for seismic anchor movement, obtaining D4+D5+D6.
Then two stress cases have been checked:
W+P1+(U1+U2+U3)<1.33SH
W+P1+(U1+U2+U3)+(D4+D5+D6)<3SA, according to ASME III.


DO you find this correct??

And my MAIN QUESTION:

For loads on restraints, I don't know which of these solutions is applicable:

Option1:
Max. load of the following load cases:
W+D1+T1+P1+U1
W+D1+T1+P1-U1
W+D1+T1+P1+U2
W+D1+T1+P1-U2
W+D1+T1+P1+U3
W+D1+T1+P1-U3
W+D1+T1+P1+D4
W+D1+T1+P1-D4
W+D1+T1+P1+D5
W+D1+T1+P1-D5
W+D1+T1+P1+D6
W+D1+T1+P1-D6

Option2:
Max. load of the following load cases:
W+D1+T1+P1+U1+D4
W+D1+T1+P1-U1-D4
W+D1+T1+P1+U1+D5
W+D1+T1+P1-U1-D5
W+D1+T1+P1+U1+D6
W+D1+T1+P1-U1-D6

NOTE: U1,U2,U3: Seismic acceleration in X,Y,Z directions
D4,D5,D6: Seismic displacements in X,Y,Z directions

Many thanks in advance! Regards