1. Seminar on STRESS RIBBON BRIDGE
Shreya Thusoo
10403EN006
IDD Part IV
Department of Civil Engineering
IIT (BHU), Varanasi

2. INTRODUCTION

3. Stress ribbon bridge: Modern analogy of ROPE BRIDGE

4. Stress Ribbon Bridge Features: Pedestrian bridges
Highly stressed freely suspended pre-stressed tendons
Precast or cast in situ deck slab
Characterized by successive and complementary smooth curves
Catenary shape or funicular shape

5. STRUCTURE

6. Stress Ribbon Bridge
Supports:

7. Stress Ribbon Bridge Supports:
Cables are pre-tensioned by anchoring into support structure, hence this region is highly stressed.
Performance may be improved by construction of:
i) flexible saddle
ii) parabolic haunch
iii) intermediate arch support

8. Stress Ribbon Bridge Simple support with constant section
Flexible saddle arrangement at support
Parabolic hunch arrangement at support
Stress ribbon supported by arch

9. Stress Ribbon Bridge Deck:
Might be pre-fabricated or cast in-situ
Stressed only by normal forces hence might be reduced by waffles
Integrated with end and intermediate supporting construction so as to work as a composite structure.

10. Stress Ribbon Bridge
Deck:
Lake Hodges Bridge, USA

11. FABRICATION

12. Segments are jointed by cast in-situ composite slabs
Stress Ribbon Bridge
Leviation Stage:
Cables are hanged from supports
Pre cast segments are slided over the bearing tendons to desired position
Segments are jointed by cast in-situ composite slabs

13. Typical precast segment on bearing cables
Stress Ribbon Bridge
Leviation Stage:
Typical precast segment on bearing cables

14. Shifting of precast segment on bearing cables
Stress Ribbon Bridge
Leviation Stage:
Shifting of precast segment on bearing cables

15. Shape at this stage determines the final sag in the bridge.
Stress Ribbon Bridge
Basic Stage:
Static analysis is done at this stage.
After sufficient hardening of joints, post tensioning is done by pre-stressing tendons.
Effect of dead load, creep, shrinkage, temperature and pre-stressing are determined.
Shape at this stage determines the final sag in the bridge.

16. Analysis of structure for all service loads is done
Stress Ribbon Bridge
Service /Ultimate Stage:
Analysis of structure for all service loads is done

17. Multi-spanned Bridges

18. Concrete or steel columns as intermediate supports
Stress Ribbon Bridge
These can be of following types:
(1)
Concrete or steel columns as intermediate supports

19. Concrete arch as intermediate supports
Stress Ribbon Bridge
(2)
Concrete arch as intermediate supports

20. Concluding notes

21. Stress Ribbon Bridge Advantages:
Minimal environmental and visual impact
Can be erected without falsework or shoring
Minimal long-term maintenance is required
Are highly desirable at place as shown below:

22. Stress Ribbon Bridge Disadvantages:
Large horizontal forces at the end and intermediate which determines economy of bridge.
Remedy- i) construction of flexible member close to supports
ii) widening of deck at the ends
iii) having an arch shaped intermediate support
Danger of overturning and oscillations due to high span to width ratio.
Remedy- i) increasing sag
ii) proper dynamic analysis

23. World's longest stress ribbon bridge in Cuenca, Spain
Recent advances:
Innovative design uses unidirectional
solid carbon fibre cables (TSC).
Unsupported spans were
significantly increased
Supporting structure was
reduced
Installation time and cost
were reduced by over 80%
World's longest stress ribbon bridge in Cuenca, Spain

24. Stress Ribbon Bridge Some important bridges in this category: Name
Country
Main Span
Rio Colorado Bridge
Costa Rica
146 m
Lake Hodges Bridge
USA
100.9 m
East Golf Cart Bridge
86.9 m
Rogue River Pedestrian Bridge 
84.73 m
Aaresteg Mülimatt
Switzerland
78 m
Glacis Bridge 
Germany
76 m
Aaresteg Rupperswil
74.05 m
Phyllis J. Tilley Memorial Bridge 
49.5 m
Kent Messenger Millennium Bridge
United Kingdom
48 m
Pùnt da Suransuns 
40 m 1) 2) 3) 4) 5) 6) 7) 8) 9)
10)

25. Stress Ribbon Bridge Jiri Strasky Rogue River Pedestrian Bridge
Lake Hodges Bridge
McLoughlin Boulevard Pedestrian Bridge
West Golf Cart Bridge
Jiri Strasky
Sacramento River Trail Pedestrian Bridge
West Golf Cart Bridge

26. Stress Ribbon Bridge References:
1) Strasky,J.- Stress-ribbon pedestrian bridges supported or suspended on arches. Brijuni Islands, July 2008.
2) Strasky,J.: Precast stress ribbon pedestrian bridges in Czechoslovakia. PCI JOURNAL, May-June 1987.
3) Strasky,J.: Stress-ribbon pedestrian bridges. International Bridge Conference. Pittsburgh 1999.
4) Nakazawa, Tsutsumi, Yokota- Experimental study on dynamic characteristics of Stress-Ribbon bridge. Ninth world Conference on Earthquake Engineering, JAPAN, Aug 2-9, 1988.
5) Strasky,J.: Stress ribbon and cable supported Pedestrian bridges

27. THANK YOU