Design of Gantry Girders (1).pptx

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1. Design of Gantry Girders

2. Crane Notations 2 11/4/2022

3. Components of an Overhead Crane 4 11/4/2022

4. Loads on Gantry Girder 5 11/4/2022

5. C C Gantry Girder Crane Girder Vertical Load Lateral Load Longitudinal Load Crab

6. Maximum Load Effects 9 11/4/2022

7. Limiting Deflection 10 11/4/2022

8. Profiles Used for Gantry Girders 11 11/4/2022

9. Impact Loads 14 11/4/2022

10. Design Step

11. Economic depth ≈ 1/12 th of the span. Width of flange ≈ 1/40 to 1/30 th of the span

12. Assume that the lateral load is resisted entirely by the top flange of the beam plus any reinforcing plates, channels etc. and the vertical load is resisted by the combined beam

13. under working loads

14. Case Study: Hoan Bridge (Milwaukee Harbor Bridge) 25 Fatigue Fractures in Center Girder E and outside Girder F. These girders collapsed on Dec. 23, 2000 after 26 years of Service 11/4/2022

15. Example Determine the max. Wheel load, shear force & bending moment for the manually operated gantry girder as per following data. Design the section & check for moment capacity of the section. Also check for fatigue strength of section of gantry girder Weight of crane girder- 150 kN , Crane capacity -180 kN , weight of crab and motor- 50 kN , Span of crane girder- 15m , minimum hook approach – 1.2 m, c/c distance between gantry column- 5m , weight of rail – 0.25 kN /m Crane operates- 225 days Working hours – 9 am to 5 pm. Max no of trip per hour – 03 Design life – 50 years . Wheel base = 2m

16. Design Step =180 kN =150 kN = 50 kN = 2m = 5m = 1.2 m = 15m

17. Crane Girder

18. 600 150 e = 0.15 + 0.3

19. Economic depth ≈ 1/12 th of the span. Width of flange ≈ 1/40 to 1/30 th of the span

20. 300 90 23.5 11.8 250 607.8 23.6 13.6

21. 250 607.8 h

22. Assume that the lateral load is resisted entirely by the top flange of the beam plus any reinforcing plates, channels etc. and the vertical load is resisted by the combined beam

23. under working loads

24. =156.09 N/mm2

25. =   =135.73 N/ mm2

26. < 135.73 N/ mm2

27.       =105.77 N/mm2

28. THANK YOU! 64 11/4/2022