Bridges

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1. BRIDGES TEAM 6 GuiDE : ASST. PROF. PREETI GHOSH DEEWAS KHARKA, 1111064 SUBHAM KUMAR RAY, 1111021 PENCHEN LEPCHA, 1111072 27 December 2013 1

2. INTRODUCTION Bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle without closing the gap below. Bridge building is not a new science. The sophistication in bridge building technology has been developing since the human civilization. 27 December 2013 2 F igure 1: a) Simplest bridge b) The Pamban Bridge

3. IMPORTANCE OF BRIDGES Connects Difficult Terrains Easy Trade and Transportation of Goods Reduces Travelling Time Military use Political and Economic importance Less Emission due to displacement 27 December 2013 3

4. COMPONENTS OF A BRIDGE 27 December 2013 4 Figure 2:

5. CLASSIFICATION OF BRIDGES According to the flexibility of superstructure According to the position of bridge floor According to the inter-span relations According to the form or type of superstructure 27 December 2013 5

6. LOADING ON BRIDGES Dead Load Live Load Buoyancy Pressure Centrifugal force Earth Pressure Seismic load Water pressure Wind load Thermal forces 27 December 2013 6 Figure 3: Live Load

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8. AESTHETICS OF BRIDGES External appearance Internal view Sequential View GUIDELINES: Beauty and Stability Bridge and Environment Integration Material Choice Moderate Lightings 27 December 2013 8 Figure 4: Aesthetics of a bridge

9. STEEL BRIDGE Steel is largely used in construction of bridge for short as well as long spans. Steel has been recognized as economic option for a range of bridges; for long span bridges, railway bridges, footbridges, and medium span highway bridges. The world’s first cast iron bridge was built at Telford , in 1779, by Abraham Darby . Steel bridges now have a proven life span extending to well over 100 years. 27 December 2013 9

10. Classification of steel bridges Steel bridges are classified according to: the type of traffic carried the type of main structural system the position of the carriage way relative to the main structural system 27 December 2013 10 Figure 5: Steel Bridge

11. REINFORCED CONCRETE BRIDGE RCC bridges are the earliest form of bridges. They are easy to construct. Arches are preferable where Bending moment is more and they are easy to design. Site Selection for RCC Bridge Straight reach of the stream Good foundation Well defined firm banks Minimum width of crossing Approaches 27 December 2013 11 Figure 6: RCC Bridge

12. Its not always possible to provide straight deck, when horizontal curves are to be provided the following design speed is to be considered: 27 December 2013 12

13. SUSPENSION BRIDGE A suspension bridge is a type of bridge in which the deck (the load-bearing portion) is hung below suspension cables on vertical suspenders. First Suspension bridge was built in 1433, in eastern Bhutan by Thangtong Gyalpo . Suspension bridge is generally preferred when the span is more than 200 m for roadway or 300 m for light traffic like motors. There are two types of suspension bridge: Un-stiffened deck type suspension bridge Stiffing girder type suspension bridge 27 December 2013 13

14. Components of a suspension bridge 27 December 2013 14 Figure 7: Components of a suspension Bridge

15. Comparison of RCC, Steel & Suspension bridges: Suspension Bridge Steel Bridge RCC Bridge Steel Cables, concrete or steel deck used as construction materials. Steel frames and concrete deck. Reinforced cement concrete Better to withstand earthquake movements than heavier and more rigid bridges. Steel can fully meet the structural requirement with even small sections. Arches are preferred where more bending moments occur. Maintenance cost is high as the cables needs to be changed Maintenance against the rusting of steel has to be done regularly which increases the cost of maintenance Their cost of maintenance is very small. Installation takes time. Quick Installation. Takes longest time for installation. 27 December 2013 15

16. BRIDGE FAILURE When a bridge collapses , many lives are put at risk. Bridge collapse is one of the most dangerous types of structural failure that can occur. Causes of Bridge failure Earthquake Fire Boat impact Flood Construction accidents Manufacturing defects Design defects Poor maintenance 27 December 2013 16 Figure 8: Bridge Failure

17. MAINTENANCE OF BRIDGES The bearings of girders should be coated with oil from time to time. The floor system of approaches and bridges should be properly maintained. The entire drainage system should be inspected for its proper functioning. The movement of foundations, if any, should be carefully inspected and all attempts should be made to stop such further movement. 27 December 2013 17

18. LANDMARK BRIDGES OF INDIA 1) The   Bandra–Worli Sea Link Official name: Rajiv Gandhi Sea Link Carries: 8 lanes of traffic Design: Cable-stayed   Length: 5.6 km Width: 40 m Opened: 30 June 2009 27 December 2013 18

19. 2) The Howrah Bridge Official name: Rabindra Setu Carries: 8 lanes of   road Design: Cantilever Length: 705  m Width: 21.6  m Opened: 3 Feb 1943 27 December 2013 19

20. 3) The Saraighat Bridge Official Name: Sarai ghat Carries: Rail cum Road Design: Truss Material: Steel Length: 1.49 km Width: 7.31 m Opened: 7 June 1963 27 December 2013 20

21. CONCLUSION Bridges connect destinations. Bridges are assets to mankind and have to last for generations as the construction of bridge influences the whole ecosystem and the change is permanent. So proper planning to adapt the bridge into the natural ecosystem has to be done. The scope of Bridge Engineering is ever booming and technology used in bridge building is also getting sophisticated. 27 December 2013 21

22. BIBLIOGRAPHY S. Ponnuswamy (Guest faculty IIT Madras )., “Bridge Engineering” Tata McGrwaw -Hill. 2 nd Edition, 2008 Prof. S.R Satish Kumar and Prof. A.R Santha Kumar (IIT Madras)., “ Design of steel structure Journal” , 2006. S.C Rangwala and K.S Rangwala ., “ Bridge Engineering” Charotar Publishing House. 14 th Edition ,2012. B.L Gupta and Amit Gupta., “Road, Railways, Bridges, Tunnels & Harbour Dock Engineering” Standard Publishers.7 th Edition, 2009. S. Ramamrutham ., “Design of RCC Structures”., Dhanpat Rai Publishing, 14 th Edition ,1989-1999 S.S. Bavikatti ., “Structure Analysis”., Vikas Publishing House. 14 th Edition, 2011. Madan Mohan Das, Bhargab Mohan Das and Mimi Das Saikia ., “Structure Analysis”., PHI Publication. 1 st Edition, 2011. Internet surfing www.wikipedia.com www.pbs.org www.design-technology.org www.britannica.com www.steelconstruction.info www.tatasteelconstruction.com 27 December 2013 22

23. THANKYOU 27 December 2013 23