hi to all forum member

one of my project has settlement cases as below


Vessels to / from Pipe Rack Bents: 1/4”
Pumps to / from Pipe Rack Bents: 1/4”
Tanks to / from Pipe Rack Bents: 1/4”
Pump to Pump (similar loading) N/A
Pump under Yard Steel to Yard Steel N/A
Pumps to Tanks: 1/4”
Pumps to Pressure Vessels 1/4”
Pumps to Drums 1/4”

in which case we have to consider settlements---in primary or secondary

also i made some load cases,just check whether i did correctly OR NOT

L1 W (HGR)
L2 W+T1+P1 (HGR)
L3 WW+HP+H (HYD)
L4 W+T1+P1+H+D1(OPE)
L5 W+T2+P1+H+D1(OPE)
L6 W+T1+P1+H(OPE)
L7 W+T2+P1+H(OPE)
L8 W+T1+P1+F1+H (OPE) OPERATING CASE (FOR T1 USUALLY OPERATING)
L9 W+T2+P1+F1+H (OPE) OPERATING CASE (FOR T2 USUALLY OPERATING)
L10 W+P1+F1+H (SUS) COLD SUSTAINED CASE CHECK
L11 W+P1+D1+H (SUS) COLD SUSTAINED CASE CHECK FOR SETTELMENTS
L12 W+P1+H(SUS) COLD SUSTAINED CASE CHECK
L13 WNC+ H (SUS) WEIGHT-NO CONTENTS
L14 W+T2+P1+F1+H+WIN1 (OPE) (OPE) WIND +X DIRECTION (SOUTHERN WINDS)
L15 W+T2+P1+F1+H+WIN2 (OPE) (OPE) WIND -X DIRECTION (SOUTHERN WINDS)
L16 W+T2+P1+F1+H+WIN3 (OPE) (OPE) WIND +Z DIRECTION (SOUTHERN WINDS)
L17 W+T2+P1+F1+H+WIN4 (OPE) (OPE) WIND -Z DIRECTION (SOUTHERN WINDS)
L18 W+T2+P1+F1+H+U1 (OPE)
L19 W+T2+P1+F1+H+U2 (OPE)
L20 T1 (EXP)
L21 T2 (EXP)
L22 L14-L7(OCC)
L23 L15-L7(OCC)
L24 L16-L7(OCC)
L25 L17-L7(OCC)
L26 L18-L7(OCC)SEISMIC IN X DIRECTION, i.e. GX=.114g
L27 L19-L7(OCC)SEISMIC IN Z DIRECTION, i.e. GZ=.114g
L28 L8-L10(EXP)EXP CODE STRESS CHECK(T1)
L29 L9-L10(EXP)EXP CODE STRESS CHECK(T2)
L30 L22+L10(OCC)WIND CODE STRESS CHECK (SOUTH WINDS)
L31 L23+L10(OCC)WIND CODE STRESS CHECK (NORTH WINDS)
L32 L24+L10(OCC)WIND CODE STRESS CHECK (WEST WINDS)
L33 L25+L10(OCC)WIND CODE STRESS CHECK (EAST WINDS)
L34 L26+L10(OCC)SEISMIC CODE STRESS CHECK IN X DIRECTION
L35 L27+L10(OCC)SEISMIC CODE STRESS CHECK IN Z DIRECTION
L36 L8-L20(SUS)HOT SUSTAINED CHECK AT TEMP T1
L37 L9-L21(SUS)HOT SUSTAINED CHECK AT TEMP T2
L38 L4-L12(EXP)EXP CODE STRESS CHECK WITH SETTLEMENTS AT TEMP T1
L39 L5-L12(EXP)EXP CODE STRESS CHECK WITH SETTLEMENTS AT TEMP T2
L40 L4-L6(EXP)SECONDARY STRESS CHECK DUE TO SETTLE MENTS
L41 L5-L7(EXP)SECONDARY STRESS CHECK DUE TO SETTLE MENTS


WHERE
F1=CONCENTRATED FORCE
D1=DISPLACEMENT DUE TO SETTLEMENTS
T1=OPE TEMP
T2 = FLEX TEMP
P1 = DESIGN PRESSURE


in L38,L39 we are inluding T1,T2 AND SETTLEMENTS,Isnt it conservative approach

is above load cases are correct????


thanks in advance

Hi,
Search forum for "Settlement" etc.
Most of ur query has been already discussed.

L36,L37 may not produce accurate results.
Read this following link.

http://65.57.255.42/ubbthreads/ubbthreads.php?ubb=showflat&Number=38602#Post38602

Load case L20,L21 may also not give proper result
Read the below link
http://65.57.255.42/ubbthreads/ubbthreads.php?ubb=showflat&Number=6556#Post6556

I don't find U3 and U4 defined, it would be necessary to define U3=-X seismic accln and U4=-Z seismic accln since the strain effect produced by U1 and U3 may not be the same.
L.. W+T2+P1+F1+H+U3 (OPE)
L.. W+T2+P1+F1+H+U4 (OPE) may be required to be defined and appropriate code case also.


load case L8-T9(EXP) is missing
Load case 40,41 may not be required as max temp. range with settlement is already covered.

In Load case L34, L35 combining seismic with F1 is like combining 2 upset condition which may not be required.

Load case
LXX L8-L6
L... LXX+L12
will also be required as a (SUS) chk.

Going back to your query,
L11 is a non code case combination.

Settlement is considered as secondary as its imposed strain on to the system.
Refer 319.2.1(c) in B31.3-2008


Hope this helps.

Thanks

"Settlement"
Vessels to / from Pipe Rack Bents: 1/4”
Pumps to / from Pipe Rack Bents: 1/4”
Tanks to / from Pipe Rack Bents: 1/4”
Pumps to Tanks: 1/4”
Pumps to Pressure Vessels 1/4”
Pumps to Drums 1/4”

That's all! You really have got to be kidding!
How lucky can you be?