Hello
I am trying to model a concrete raft foundation on soil in STAAD. I have read the examples within STAAD help and also some of the discussion threads on here. However, I feel like they tend to contradict each other in parts. I am not getting sensible answers from STAAD, presumably relating to setting the compression only springs. I believe I have followed the example (UK_27) within the technical reference manual.
See below input file - I have removed the geometry for clarity. Can any of the STAAD team please review this and advise where I am going wrong.
Thanks
STAAD SPACE
SET NL 9
.....
ELEMENT PROPERTY
2 TO 1873 THICKNESS 0.3
DEFINE MATERIAL START
ISOTROPIC CONCRETE
E 2.17185e+007
POISSON 0.17
DENSITY 23.5616
ALPHA 1e-005
DAMP 0.05
TYPE CONCRETE
STRENGTH FCU 27579
END DEFINE MATERIAL
CONSTANTS
MATERIAL CONCRETE ALL
SPRING COMPRESSION
1 to 1971 KFY
SUPPORTS
1 TO 1971 PLATE MAT DIRECT Y SUBGRADE 1000
LOAD 1 LOADTYPE None TITLE FOUNDATION SW
ELEMENT LOAD
2 TO 1873 PR GY -7.2
PERFORM ANALYSIS PRINT STATICS CHECK
CHANGE
LOAD 2 LOADTYPE None TITLE MODULE SW @ 0.5T/M2
JOINT LOAD
299 363 1613 1671 FY -21.56
315 331 347 1629 1645 1661 FY -43.13
PERFORM ANALYSIS PRINT STATICS CHECK
CHANGE
LOAD 3 LOADTYPE None TITLE MODULE FLOOR LIVE @ 5KN/M2
JOINT LOAD
299 363 1613 1671 FY -22
315 331 347 1629 1645 1661 FY -44
PERFORM ANALYSIS PRINT STATICS CHECK
CHANGE
LOAD 4 LOADTYPE None TITLE MODULE ROOF LIVE @ 0.75 KN/M2
JOINT LOAD
299 363 1613 1671 FY -3.3
315 331 347 1629 1645 1661 FY -6.6
PERFORM ANALYSIS PRINT STATICS CHECK
CHANGE
LOAD 5 LOADTYPE None TITLE BASEMENT LIVE @ 1 KN/M2
JOINT LOAD
299 363 1613 1671 FY -4.4
315 331 347 1629 1645 1661 FY -8.8
PERFORM ANALYSIS PRINT STATICS CHECK
CHANGE
LOAD 6 LOADTYPE None TITLE WIND IN FZ @ 3KN/M2
JOINT LOAD
299 363 1613 1677 FZ -44.5
299 363 1613 1677 MX -20
299 363 FY -72
1613 1677 FY 72
PERFORM ANALYSIS PRINT STATICS CHECK
CHANGE
LOAD 7 TITLE VERTICAL ONLY
REPEAT LOAD
1 1.0 2 1.0 3 1.0 4 1.0 6 1.0
PERFORM ANALYSIS PRINT STATICS CHECK
CHANGE
LOAD 8 TITLE MAX VERTICAL + WIND
REPEAT LOAD
1 1.0 2 1.0 3 1.0 4 1.0 5 1.0 6 1.0 7 1.0
PERFORM ANALYSIS PRINT STATICS CHECK
CHANGE
LOAD 9 TITLE MIN VERTICAL + WIND
REPEAT LOAD
1 1.0 2 1.0 5 1.0
PERFORM ANALYSIS PRINT STATICS CHECK
FINISH