Week 8 Challenge
Aim: To calculate centrifugal loads as per given data and analyse the given bridge in Staad Pro
Introduction : The given bridge is of Composite steel girder bridge. It has 4 girders,
- The span of the bridge is 12 m.
- Width of carriage way is 7 m.
- The bridge is subjected to a live load of Class 70R tracked vehicle.
- The design speed of the vehicles is 75 km/hr.
- The radius of curvature in the bridge is 3 m.
Procedure:
Step 1 - Calculation of centrifugal loads
CF=WV^2/127R
W=70kN (As per IRC 6, 35tx2)
V = 75km/hr
R=3m
CF = 1033.5kN
Step 2 - Create Staad Model
In Staad Pro main window click on geometry tab in left side, create 1st node at coordinate 0,0,0 and then for pier height create node at height 10m 0,10,0, then create a beam between these two nodes.
Copy this member by ctrl c and paste it at a distance of 12m (span length) by ctrl v by X=12m.
Create fixed support from support tab and assign it to the bottom of both the piers. Create property by selecting circle of 1.5m dia concrete material and assign it to both the pier.
Copy paste both the piers in Z=7m as carriage way width is 7m
Create a member connecting top of both the pier by selecting add member from point to point from geometry tab in Z direction.
Divide this beams in 3 parts by selecting them and right click to insert node in 2 points, Then connect all the nodes in X direction and assign them property of girder
Longitudinal direction girder property
Transverse direction girder property
Assign centrifugal Load
Run model for analysis
Results:
Deflection diagram
Shear force diagram
Max Shear in girder
Bending moment diagram
Max Mz in girder
Report:
1. STAAD SPACE
INPUT FILE: C:\Users\Muthulakshmi\Downloads\Old Laptop data of 1st week\Challenge Staad\Challenge 8.STD
2. START JOB INFORMATION
3. ENGINEER DATE 19-JUL-22
4. END JOB INFORMATION
5. INPUT WIDTH 79
6. UNIT METER KN
7. JOINT COORDINATES
8. 1 0 0 0; 2 0 10 0; 3 0 0 7.00001; 4 0 10 7.00001; 5 12 0 0; 6 12 10 0
9. 7 12 0 7.00001; 8 12 10 7.00001; 9 0 10 2.33334; 10 0 10 4.66668
10. 11 12 10 2.33334; 12 12 10 4.66668
11. MEMBER INCIDENCES
12. 11 1 2; 12 3 4; 13 5 6; 14 7 8; 15 2 6; 16 4 8; 17 2 9; 18 6 11; 19 9 10
13. 20 10 4; 21 11 12; 22 12 8; 23 9 11; 24 10 12
14. UNIT INCHES KIP
15. DEFINE MATERIAL START
16. ISOTROPIC CONCRETE
17. E 3150
18. POISSON 0.17
19. DENSITY 8.68E-05
20. ALPHA 5.5E-06
21. DAMP 0.05
22. G 1346.15
23. TYPE CONCRETE
24. STRENGTH FCU 4
25. ISOTROPIC STEEL
26. E 29000
27. POISSON 0.3
28. DENSITY 0.000283
29. ALPHA 6.5E-06
30. DAMP 0.03
31. G 11200
32. TYPE STEEL
33. STRENGTH RY 1.5 RT 1.2
34. END DEFINE MATERIAL
35. UNIT METER KN
36. MEMBER PROPERTY
37. 11 TO 14 PRIS YD 1.5
38. 15 16 23 24 TAPERED 1 0.015 1 0.015 0.15 0.5 0.015
STAAD SPACE -- PAGE NO. 2
39. 17 TO 22 TAPERED 1.5 0.015 1.5 0.5 0.015 0.5 0.015
40. UNIT INCHES KIP
41. CONSTANTS
42. MATERIAL STEEL MEMB 15 TO 24
43. MATERIAL CONCRETE MEMB 11 TO 14
44. SUPPORTS
45. 1 3 5 7 FIXED
46. UNIT METER KN
47. DEFINE MOVING LOAD
48. TYPE 1 LOAD 440 440
49. DIST 3.6
50. LOAD 1 LOADTYPE LIVE TITLE CENTRIFUGAL LOAD
51. LOAD GENERATION 20 ADD LOAD 1
52. TYPE 1 0 10 3.5 XINC 1
53. PERFORM ANALYSIS
P R O B L E M S T A T I S T I C S
-----------------------------------
NUMBER OF JOINTS 12 NUMBER OF MEMBERS 14
NUMBER OF PLATES 0 NUMBER OF SOLIDS 0
NUMBER OF SURFACES 0 NUMBER OF SUPPORTS 4
Using 64-bit analysis engine.
SOLVER USED IS THE IN-CORE ADVANCED MATH SOLVER
TOTAL PRIMARY LOAD CASES = 21, TOTAL DEGREES OF FREEDOM = 48
TOTAL LOAD COMBINATION CASES = 0 SO FAR.
STAAD SPACE -- PAGE NO. 3
54. FINISH