Design of flyover elements
- 1. ANALYSIS AND DESIGN OF FLYOVER ELEMENTS WITH ELASTOMERS Presented by, Guided by, 1. R.V.Subbulakshmi S. Alarmelumangai, M.E 2. E.Yasodai Assistant Professor 3. S.P.Bavithra Department of CE 4. A.Parkavi A.V.C College of Engineering
- 2. OBJECTIVE • To develop the simple method of seismic resistant in flyover • To analyze and design the flyover elements.
- 3. ABSTRACT • The aim of this investigation is provision of rubber bearing isolators in flyover to withstand earthquake induced stress as economically as possible. • Flyover is high level road bridge. • There is a necessity to construct a road over bridge in ongoing bypass project connecting Vallam to Thiruvaiyar, since the bypass alignment crosses railway line in between Alakudi and Tanjore.
- 4. FLYOVER • A grade separated structure connects road at different levels for the purpose of reducing vehicle congestion. • To make road easily accessible for day to day traffic.
- 5. FLYOVER ELEMENTS SUPER-STRUCTURE: 1. Deck slab, Approach slab, 2. Girder, Bearing, 3. Parapet wall and Hand rail. SUB-STRUCTURE: 1. Abutment, Pier, Wing-wall. 2. Foundation.
- 6. NECESSITY OF PROJECT • At railway crossing there is a high traffic congestion in terms of train passing by or traffic on the road. • In such a case flyover is indispensable. • Furthermore earthquake causes failure of structures leads to several loss. Structure has to withstand the earthquake force. • So in our project we designed flyover elements with earthquake resistant technique.
- 7. BASE ISOLATION SYSTEM • It is one of the most popular earthquake resistant technique which isolates substructure and super structure during earthquake. • Here elastomeric bearing is used. It is ductility incorporated technology which consist of a layer of neoprene bonded to steel laminates.
- 8. CONTD.., • Elastomers is placed between deck slab and pier.
- 9. LITERATURE REVIEW • ANALYSIS OF T BEAM BRIDGE DECK USING FINITE ELEMENT METHOD: T Beam Bridge decks are one of the principle types of cast-in place concrete decks. It is suitable when span is 10-25m. A simple span T beam bridge was analyzed by using IRC CLASS AA loadings as a one dimensional structure. Girder is analyzed as per Courbon’s method. IRC class AA loading consist of either tracked vehicle of 70 tons or wheeled vehicle of 40 tons. Courbon’s method is suitable for deck having span to width ratio greater than 2 but less than 4.
- 10. EARTHQUAKE- A CASE STUDY • A devastating 7.8 R earthquake struck northern Nepal on April 25, 2015 injuring over 22,000 people in addition to causing significant infrastructure damage. • Bhuj earthquake of magnitude 7.7 R occurred on January 26, 2001 had devastated many human lives nearly 18,000 peoples are died • So it is necessary to control seismic potential on structure in order to access a protection towards human race and structures.
- 11. ALSO WE LOSS OUR PRIDE IDENTITY (NEPAL)
- 12. METHODOLOGY Site Selection Data collection Traffic Survey Analysis Design of Structural Components
- 13. SITE SELECTED • We are proposing our flyover project in lieu of existing railway level crossing at Alakudi near Tanjore in Vallam to Thiruvaiyaru Bypass (on going).
- 14. SITE DETAILS 1. Type of road: State highway(SH 100) 2. Name of the road: Tanjore-Vallam road 3. Distance between level crossing (boom to boom): 30m 4. Type of rail gauge: Broad gauge 5. TVU (train vehicle unit): 55 units/ day 6. Seismic zone: II
- 15. Prop. Bye Pass Total Length : 14.265 Km Lane Configuration Km 0/0 - 1/6 Four Lane, Km 1/6 – 14/265 Two Lane Proposed ROB CH 5706 PROPOSED LOCATION
- 16. TRAFFIC SURVEY DETAILS • MANUAL METHOD OF COUNTING
- 17. TRAFFIC DENSITY VEHICLE TYPE TRAFFIC DENSITY (veh/km) Two wheeler 523 Auto 258 Buses 44 Car 50 Truck 22 Other vehicles (tractor, cycle ) 68 (app) Location: Tanjore (Time: 9.30-10.30 A.M)
- 18. ANALYSIS • IRC CLASS AA LOADING is considered for design of flyover elements. It consist of either tracked vehicle (700 kN) or wheeled vehicle (400 kN). • Example: combat tank used by army.
- 19. DESIGN OF STRUCTURAL ELEMENTS Type of bridge deck : T-Beam cum slab Loading : IRC 6 (Class AA loading considered) Bridge deck : Working stress method Bearing : IRC 83-part II(WSM) Pier : IRC 78 & SP 16 Design Aids (LSM) No of piers : 14 No of abutment : 2 Number of lane : 2 Overall width : 8m Gradient : 1 in 30m Length : 440m 1. Longitudinal girder 2. Cross girder : : 3 no’s 5 no’s
- 20. DESIGN OF DECK SLAB
- 21. CONTD… Kerb 600x300mm Wearing coat 80mm Thick of deck slab 250mm Area of reinforcement for shorter span 16 mm ϕ bars at 150 mm c/c Area of reinforcement for longer span 10 mm ϕ bars at 150 mm c/c
- 23. DESIGN OF LONGITUDINAL GIRDER • Analysis is done using COURBON’S THEORY Width of main girder =300mm Depth of main girder =1600mm Area of reinforcement 20 no’s of 32 mm ϕ rods in 4 rows Stirrups 10 mm ϕ bars – four legged stirrups at 200 mm c/c
- 24. DESIGN OF CROSS GIRDER • Analysis is done using COURBON’S THEORY Width of cross girder =300mm Depth of cross girder =1600mm Area of reinforcement 4 no’s of 20 mm ϕ rods Stirrups 10 mm ϕ bars – four legged stirrups at 150 mm c/c
- 26. DESIGN OF ELASTOMERIC BEARING • This design conforms IRC 83 PART-II. • Provide 3nos of 400 X 250 X 50 mm laminated elastomeric bearing between concrete pedestals of 650 X 450 X 120 mm. • It offers flexibility between pier and deck slab during earthquake as per shown.
- 28. DESIGN OF SUB-STRUCTURE • DESIGN OF PIER CAP: This conforms IRC 78-2000. Length of pier cap 10.6 m Width of pier cap 1.2 m Effective depth(d1) 1.8 m Tension reinforcement 20 no’s of 32 mm ϕ rods Compression reinforcement 36 no’s of 32 mm ϕ rods Side-face reinforcement 8 no’s of 20 mm ϕ rods in 2 rows Shear reinforcement 22 mm ϕ rods – four legged stirrups at 500mm c/c
- 29. DESIGN OF PIER Length of pier 5.6 m Width of pier 1.2 m Height of pier 5.2 m Tension reinforcement 68 no’s of 32 mm ϕ rods Curtailment 34 no’s of 32 mm ϕ rods Shear reinforcement 12 mm ϕ rods – four legged stirrups at 250mm c/c
- 32. CONCLUSION • Road traffic jams continue to remain a major problem in most cities around the world especially in developing regions resulting in massive delays, increased fuel wastage and monetary losses. Hence grade separated structures offers a free flow of traffic. • In this project we designed a road over bridge elements in order to avoid traffic congestion in our proposed project site. Furthermore earthquake causes major disasters and leads to failure of structures. • So in our project we are introducing an elastomeric base bearing in the bridge which protect the structure during earthquake. All elements are designed manually.
- 33. REFERENCE • Ponnuswamy.S, “Bridge Engineering” publisher, Tata MeGraw-Hill, New Delhi. • Krishna Raju. N, “Advanced reinforced concrete design”, CBS publishers and distributors Delhi, 2006. • IS 456-2000 Indian standards - Plain and Reinforced concrete – code of practice. • IRC 6-2000 Specification for Road bridges-Section-2-Code of practice.