SEMINAR ON STRESS RIBBON
BRIDGE
Shreya Thusoo10403EN006IDD Part IVDepartment of Civil EngineeringIIT (BHU), Varanasi
INTRODUCTION
Stress ribbon bridge: Modern analogy of ROPE 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
Stress Ribbon Bridge
STRUCTURE
Supports:
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
Stress Ribbon Bridge
Stress Ribbon Bridge
Simple support with constant section
Flexible saddle arrangement at support
Parabolic hunch arrangement at support
Stress ribbon supported by arch
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.
Stress Ribbon Bridge
Deck:Stress Ribbon Bridge
Lake Hodges Bridge, USA
FABRICATION
Stress Ribbon Bridge
Leviation Stage:
I. Cables are hanged from supportsII. Pre cast segments are slided over the bearing tendons to
desired positionIII. Segments are jointed by cast in-situ composite slabs
Stress Ribbon Bridge
Leviation Stage:
Typical precast segment on bearing cables
Stress Ribbon Bridge
Leviation Stage:
Shifting of precast segment on bearing cables
Stress Ribbon Bridge
Basic Stage:
I. Static analysis is done at this stage.II. After sufficient hardening of joints, post tensioning is done by
pre-stressing tendons.III. Effect of dead load, creep, shrinkage, temperature and pre-
stressing are determined.IV. Shape at this stage determines the final sag in the bridge.
Stress Ribbon Bridge
Service /Ultimate Stage:
Analysis of structure for all service loads is done
MULTI-SPANNED BRIDGES
Stress Ribbon Bridge
These can be of following types:
(1)
Concrete or steel columns as intermediate supports
Stress Ribbon Bridge
(2)
Concrete arch as intermediate supports
CONCLUDING NOTES
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:
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
Stress Ribbon Bridge
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%
Stress Ribbon Bridge
World's longest stress ribbon bridge in Cuenca, Spain
Some important bridges in this category:
Stress Ribbon Bridge
Name Country Main Span
Rio Colorado Bridge Costa Rica 146 m
Lake Hodges Bridge USA 100.9 m
East Golf Cart Bridge USA 86.9 m
Rogue River Pedestrian Bridge USA 84.73 m
Aaresteg Mülimatt Switzerland 78 m
Glacis Bridge Germany 76 m
Aaresteg Rupperswil Switzerland 74.05 m
Phyllis J. Tilley Memorial Bridge USA 49.5 m
Kent Messenger Millennium Bridge United Kingdom 48 m
Pùnt da Suransuns Switzerland 40 m
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
Stress Ribbon Bridge
Jiri Strasky
West Golf Cart Bridge
West Golf Cart Bridge
Sacramento River Trail Pedestrian Bridge
Rogue River Pedestrian Bridge
McLoughlin Boulevard Pedestrian
Bridge
Lake Hodges Bridge
Stress Ribbon Bridge
References:
1) Strasky,J.- Stress-ribbon pedestrian bridges supported or suspended on arches. Brijuni Islands, 10-14 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
THANK YOU
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