EX. US-3 Soil Springs for Portal Frame
A portal frame type steel structure is sitting on concrete footings. The soil is to be considered as an elastic foundation. The value of soil subgrade reaction is known from which spring constants are calculated by multiplying the subgrade reaction by the tributary area of each modeled spring.
This problem is installed with the program by default to C:\Users\Public\Public Documents\STAAD.Pro 2024\Samples \Sample Models\US\US-3 Soil Springs for Portal Frame.STD when you install the program.
Where:
- B = 20 ft, H = 10 ft, F1 = 4 ft, F2 = 8 ft
- P = 5 kips, w = 3 kips/ft
- Soil Subgrade Reaction = 250 kips/ft3
Springs of Joints | Spring Constant |
---|---|
1, 5, 10, & 14 (Edges) |
8 x 1 x 250 = 2,000 kips/ft |
2, 3, 4, 11, 12, & 13 (Interior) |
8 x 2 x 250 = 4,000 kips/ft |
Actual input is shown in bold lettering followed by explanation.
STAAD PLANE PORTAL ON FOOTING FOUNDATION
Every input has to start with the term STAAD
. The term PLANE
signifies that the structure is a plane frame structure and the geometry is defined through X and Y axes.
UNIT FT KIPS
Defines the input units for the data that follows.
JOINT COORDINATES
1 0.0 0.0 0.0 5 8.0 0.0 0.0
6 4.0 10.0 0.0 ; 7 4.0 20.0 0.0
8 24.0 20.0 0.0 ; 9 24.0 10.0 0.0
10 20.0 0.0 0.0 14 28.0 0.0 0.0
Joint number followed by X, Y and Z coordinates are provided above. Since this is a plane structure, the Z coordinates are given as all zeros.
MEMBER INCIDENCES
1 1 2 4
5 3 6 ; 6 6 7
7 7 8 ; 8 6 9
9 8 9 ; 10 9 12
11 10 11 14
Defines the members by the joints to which they are connected.
MEMBER PROPERTIES AMERICAN
1 4 11 14 PRIS YD 1.0 ZD 8.0
2 3 12 13 PRIS YD 2.0 ZD 8.0
5 6 9 10 TA ST W10X33
7 8 TA ST W12X26
The first two lines define member properties as prismatic (PRIS
) followed by depth (YD
) and width (ZD
) values. The program will calculate the properties necessary to perform the analysis. See
G.6.1 Prismatic Properties
for additional information. Member properties for the remaining members are chosen from the British steel table. The term ST
stands for standard single section.
* E FOR STEEL IS 29,000 AND FOR CONCRETE 3000
UNIT INCHES
DEFINE MATERIAL START
ISOTROPIC STEEL
E 29000
POISSON 0.3
DENSITY 0.283e-003
ALPHA 6e-006
DAMP 0.03
TYPE STEEL
STRENGTH FY 36 FU 58 RY 1.5 RT 1.2
ISOTROPIC CONCRETE
E 3000
POISSON 0.17
DENSITY 8.68e-005
ALPHA 5e-006
DAMP 0.05
G 1346.15
TYPE CONCRETE
STRENGTH FCU 4
END DEFINE MATERIAL
CONSTANTS
MATERIAL STEEL MEMB 5 TO 10
MATERIAL CONCRETE MEMB 1 TO 4 11 TO 14
The CONSTANT
command initiates input for material constants like modulus of elasticity, Density, and Poisson's ratio.
The length unit is changed from FT
to INCH
to facilitate the input in familiar units.
UNIT FT
SUPPORTS
2 TO 4 11 TO 13 FIXED BUT MZ KFY 4000.
1 5 10 14 FIXED BUT MZ KFY 2000.
The supports for the structure are specified above. The first set of joints are supports restrained in all directions except global moment-z (MZ
).
Also, a spring having a spring constant of 4,000 kip/ft is provided in the global Y direction at these nodes.
The second set is similar to the former except for a different value of the spring constant.
LOADING 1 DEAD AND WIND LOAD COMBINED
Load case 1 is initiated followed by a title.
SELF Y -1.0
The selfweight of the structure is specified as acting in the global Y direction with a -1.0 factor.
Since global Y is vertically upwards, the -1.0 factor indicates that this load will act downwards.
JOINT LOAD
6 7 FX 5.0
Load 1 contains joint loads also. FX
indicates that the load is a force in the global X direction.
MEMBER LOAD
7 8 UNI GY -3.0
Load 1 contains member loads also. GY
indicates that the load acts in the global Y direction. The term UNI
stands for uniformly distributed load, and is applied on members 7 and 8, acting downwards.
PERFORM ANALYSIS
This command instructs the program to proceed with the analysis.
PRINT ANALYSIS RESULTS
The above PRINT
command instructs the program to print analysis results which include joint displacements, member forces and support reactions.
FINISH
This command terminates the STAAD run.
Input File
STAAD PLANE PORTAL ON FOOTING FOUNDATION
UNIT FT KIPS
JOINT COORDINATES
1 0.0 0.0 0.0 5 8.0 0.0 0.0
6 4.0 10.0 0.0 ; 7 4.0 20.0 0.0
8 24.0 20.0 0.0 ; 9 24.0 10.0 0.0
10 20.0 0.0 0.0 14 28.0 0.0 0.0
MEMBER INCIDENCES
1 1 2 4
5 3 6 ; 6 6 7
7 7 8 ; 8 6 9
9 8 9 ;10 9 12
11 10 11 14
MEMBER PROPERTIES AMERICAN
1 4 11 14 PRIS YD 1.0 ZD 8.0
2 3 12 13 PRIS YD 2.0 ZD 8.0
5 6 9 10 TA ST W10X33
7 8 TA ST W12X26
* E FOR STEEL IS 29,000 AND FOR CONCRETE 3000
UNIT INCHES
DEFINE MATERIAL START
ISOTROPIC STEEL
E 29000
POISSON 0.3
DENSITY 0.283e-003
ALPHA 6e-006
DAMP 0.03
TYPE STEEL
STRENGTH FY 36 FU 58 RY 1.5 RT 1.2
ISOTROPIC CONCRETE
E 3000
POISSON 0.17
DENSITY 8.68e-005
ALPHA 5e-006
DAMP 0.05
G 1346.15
TYPE CONCRETE
STRENGTH FCU 4
END DEFINE MATERIAL
CONSTANTS
MATERIAL STEEL MEMB 5 TO 10
MATERIAL CONCRETE MEMB 1 TO 4 11 TO 14
UNIT FT
SUPPORTS
2 TO 4 11 TO 13 FIXED BUT MZ KFY 4000.
1 5 10 14 FIXED BUT MZ KFY 2000.
LOADING 1 DEAD AND WIND LOAD COMBINED
SELF Y -1.0
JOINT LOAD
6 7 FX 5.0
MEMBER LOAD
7 8 UNI GY -3.0
PERFORM ANALYSIS
PRINT ANALYSIS RESULTS
FINISH
PAGE NO. 1
****************************************************
* *
* STAAD.Pro 2023 *
* Version 23.00.03.** *
* Proprietary Program of *
* Bentley Systems, Inc. *
* Date= JUL 4, 2024 *
* Time= 11:28:34 *
* *
* Licensed to: Bentley Systems Inc *
****************************************************
1. STAAD PLANE PORTAL ON FOOTING FOUNDATION
INPUT FILE: D:\Documentation\STAAD.Pro\_Automated_Py\output\2024-07-04\SPro_Output_Input_Files\Sample .. .STD
2. UNIT FT KIPS
3. JOINT COORDINATES
4. 1 0.0 0.0 0.0 5 8.0 0.0 0.0
5. 6 4.0 10.0 0.0 ; 7 4.0 20.0 0.0
6. 8 24.0 20.0 0.0 ; 9 24.0 10.0 0.0
7. 10 20.0 0.0 0.0 14 28.0 0.0 0.0
8. MEMBER INCIDENCES
9. 1 1 2 4
10. 5 3 6 ; 6 6 7
11. 7 7 8 ; 8 6 9
12. 9 8 9 ;10 9 12
13. 11 10 11 14
14. MEMBER PROPERTIES AMERICAN
15. 1 4 11 14 PRIS YD 1.0 ZD 8.0
16. 2 3 12 13 PRIS YD 2.0 ZD 8.0
17. 5 6 9 10 TA ST W10X33
18. 7 8 TA ST W12X26
19. * E FOR STEEL IS 29,000 AND FOR CONCRETE 3000
20. UNIT INCHES
21. DEFINE MATERIAL START
22. ISOTROPIC STEEL
23. E 29000
24. POISSON 0.3
25. DENSITY 0.283E-003
26. ALPHA 6E-006
27. DAMP 0.03
28. TYPE STEEL
29. STRENGTH FY 36 FU 58 RY 1.5 RT 1.2
30. ISOTROPIC CONCRETE
31. E 3000
32. POISSON 0.17
33. DENSITY 8.68E-005
34. ALPHA 5E-006
35. DAMP 0.05
36. G 1346.15
37. TYPE CONCRETE
38. STRENGTH FCU 4
PORTAL ON FOOTING FOUNDATION -- PAGE NO. 2
39. END DEFINE MATERIAL
40. CONSTANTS
41. MATERIAL STEEL MEMB 5 TO 10
42. MATERIAL CONCRETE MEMB 1 TO 4 11 TO 14
43. UNIT FT
44. SUPPORTS
45. 2 TO 4 11 TO 13 FIXED BUT MZ KFY 4000.
46. 1 5 10 14 FIXED BUT MZ KFY 2000.
47. LOADING 1 DEAD AND WIND LOAD COMBINED
48. SELF Y -1.0
49. JOINT LOAD
50. 6 7 FX 5.0
51. MEMBER LOAD
52. 7 8 UNI GY -3.0
53. PERFORM ANALYSIS
P R O B L E M S T A T I S T I C S
-----------------------------------
NUMBER OF JOINTS 14 NUMBER OF MEMBERS 14
NUMBER OF PLATES 0 NUMBER OF SOLIDS 0
NUMBER OF SURFACES 0 NUMBER OF SUPPORTS 10
Using 64-bit analysis engine.
SOLVER USED IS THE IN-CORE ADVANCED MATH SOLVER
TOTAL PRIMARY LOAD CASES = 1, TOTAL DEGREES OF FREEDOM = 32
TOTAL LOAD COMBINATION CASES = 0 SO FAR.
54. PRINT ANALYSIS RESULTS
ANALYSIS RESULTS
PORTAL ON FOOTING FOUNDATION -- PAGE NO. 3
JOINT DISPLACEMENT (INCH RADIANS) STRUCTURE TYPE = PLANE
------------------
JOINT LOAD X-TRANS Y-TRANS Z-TRANS X-ROTAN Y-ROTAN Z-ROTAN
1 1 0.00000 -0.04256 0.00000 0.00000 0.00000 -0.00028
2 1 0.00000 -0.04892 0.00000 0.00000 0.00000 -0.00023
3 1 0.00000 -0.05439 0.00000 0.00000 0.00000 -0.00020
4 1 0.00000 -0.05854 0.00000 0.00000 0.00000 -0.00017
5 1 0.00000 -0.06134 0.00000 0.00000 0.00000 -0.00010
6 1 0.32187 -0.07856 0.00000 0.00000 0.00000 -0.00483
7 1 0.64023 -0.09085 0.00000 0.00000 0.00000 -0.00669
8 1 0.62253 -0.10247 0.00000 0.00000 0.00000 0.00393
9 1 0.32940 -0.08883 0.00000 0.00000 0.00000 0.00014
10 1 0.00000 -0.03597 0.00000 0.00000 0.00000 -0.00055
11 1 0.00000 -0.04884 0.00000 0.00000 0.00000 -0.00051
12 1 0.00000 -0.06099 0.00000 0.00000 0.00000 -0.00049
13 1 0.00000 -0.07163 0.00000 0.00000 0.00000 -0.00043
14 1 0.00000 -0.08045 0.00000 0.00000 0.00000 -0.00035
PORTAL ON FOOTING FOUNDATION -- PAGE NO. 4
SUPPORT REACTIONS -UNIT KIPS FEET STRUCTURE TYPE = PLANE
-----------------
JOINT LOAD FORCE-X FORCE-Y FORCE-Z MOM-X MOM-Y MOM Z
2 1 0.00 16.31 0.00 0.00 0.00 0.00
3 1 -0.60 18.13 0.00 0.00 0.00 0.00
4 1 0.00 19.51 0.00 0.00 0.00 0.00
11 1 0.00 16.28 0.00 0.00 0.00 0.00
12 1 -9.40 20.33 0.00 0.00 0.00 0.00
13 1 0.00 23.88 0.00 0.00 0.00 0.00
1 1 0.00 7.09 0.00 0.00 0.00 0.00
5 1 0.00 10.22 0.00 0.00 0.00 0.00
10 1 0.00 5.99 0.00 0.00 0.00 0.00
14 1 0.00 13.41 0.00 0.00 0.00 0.00
PORTAL ON FOOTING FOUNDATION -- PAGE NO. 5
MEMBER END FORCES STRUCTURE TYPE = PLANE
-----------------
ALL UNITS ARE -- KIPS FEET (LOCAL )
MEMBER LOAD JT AXIAL SHEAR-Y SHEAR-Z TORSION MOM-Y MOM-Z
1 1 1 0.00 7.09 0.00 0.00 0.00 0.00
2 0.00 -4.69 0.00 0.00 0.00 11.79
2 1 2 0.00 21.00 0.00 0.00 0.00 -11.79
3 0.00 -16.20 0.00 0.00 0.00 48.99
3 1 3 0.00 -22.54 0.00 0.00 0.00 -67.92
4 0.00 27.34 0.00 0.00 0.00 18.05
4 1 4 0.00 -7.82 0.00 0.00 0.00 -18.05
5 0.00 10.22 0.00 0.00 0.00 0.00
5 1 3 56.87 0.60 0.00 0.00 0.00 18.93
6 -56.54 -0.60 0.00 0.00 0.00 -12.95
6 1 6 29.01 -11.36 0.00 0.00 0.00 -50.40
7 -28.68 11.36 0.00 0.00 0.00 -63.23
7 1 7 16.36 28.68 0.00 0.00 0.00 63.23
8 -16.36 31.84 0.00 0.00 0.00 -94.86
8 1 6 -6.96 27.53 0.00 0.00 0.00 63.35
9 6.96 32.99 0.00 0.00 0.00 -117.94
9 1 8 31.84 16.36 0.00 0.00 0.00 94.86
9 -32.17 -16.36 0.00 0.00 0.00 68.77
10 1 9 65.16 9.40 0.00 0.00 0.00 49.17
12 -65.49 -9.40 0.00 0.00 0.00 44.85
11 1 10 0.00 5.99 0.00 0.00 0.00 0.00
11 0.00 -3.59 0.00 0.00 0.00 9.59
12 1 11 0.00 19.87 0.00 0.00 0.00 -9.59
12 0.00 -15.07 0.00 0.00 0.00 44.54
13 1 12 0.00 -30.08 0.00 0.00 0.00 -89.39
13 0.00 34.88 0.00 0.00 0.00 24.42
14 1 13 0.00 -11.01 0.00 0.00 0.00 -24.42
14 0.00 13.41 0.00 0.00 0.00 0.00
PORTAL ON FOOTING FOUNDATION -- PAGE NO. 6
************** END OF LATEST ANALYSIS RESULT **************
55. FINISH
*********** END OF THE STAAD.Pro RUN ***********
**** DATE= JUL 4,2024 TIME= 11:28:35 ****
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