This is my design project . The main objective of our project to reduce the traffic in the best economic way.

1. DESIGN OF POST
TENSIONED
DECK SLAB FOR FLYOVER

2. TEAM MEMBERS:
V.AKILAN
M.P.MALAR RAJAN
D.MANI KANDAN
M.SWAMI NATHAN
PROJECT GUIDE :
MR.S.ANBU M.E., AMIE.,
Asst Professor
Department of Civil Engineering
Sri Sairam Engineering College

3. ABSTRACT
Our project deals with the Design of Fly over. The
location is at KALLAKURICHI, VILLUPURAM DIST
which is facing major traffic problems. We have done a
traffic survey and designed the slab deck for this Fly
over. It consists of
 deck slab
 longitudinal girders
 Cross girders

4. METHODOLOGY
• Slab is designed by working stress method as per
the recommendation of IRC: 21-2000, Clause
304.2.1.Deck slab is designed for maximum moment due
to deck action. The T beam designed as the IRC: 21-
2000. The deck beam is designed as a cantilever on a
pier. All the elements are designed by using M20 grade
concrete and Fe415grade steel.

5. • For calculating reaction factors courbons’s method is
adopted . It is the simplest and is application when the
following conditions are satisfied.
• The ratio of span to width of deck is
greater than 2 but less than 4.
• The cross girder extends to a depth
of at least 0.75 times depth of
longitudinal girders.
• The longitudinal girders are
interconnected by at least 5
symmetrically spaced cross girders.

6. OBJECTIVE
(i) Reduced traffic also resulting in land gains which can be
utilized to enhance the pedestrian space and increase pedestrian
amenity.
(ii) Improvement and increase in size of pedestrian sidewalks
and footpaths, as well as general urban design elements to create
an environment that is conducive to pedestrian activity.
(iii) Reduced traffic congestion, conflicts, and land gains
resulting in a safer and more efficient circulation of traffic.
(iv) Reduction of traffic, which is expected to reduce the
number of accidents and potential conflicts that occur within the
area, thus saving human life as well as the economy of the region.

7. DESIGN PROCEDURE
ASSUME SECTION
Effective span of Tee-beam = 30m.
Width of carriage way = 7.5m.
Thickness of wearing coat = 80mm.
M-20 grade concrete and Fe-415 grade
HSD bars
Live load = I.R.C class AA tracked vehicle

8. CROSS SECTION OF DECK
• Four main girders are provided at 2.5m centre
• Thickness of deck slab = 250mm
• Wearing coat = 80mm.
• Kerb 600mm wide by 300mm deep are provided.
• Cross girders are provided at every 5m intervals.

10. DESIGN OF INTERIOR SLAB PANELS
BENDING MOMENT
It is due to
Live load
Dead load
Live load is calculated from class AA tracked vehicle.
One wheel laced at the centre for max Bending
moment

11. Dead load is calculated by considering
Dead load of the slab
Dead load of wearing coat (80mm)
Dead load moment is calculated from class AA
tracked vehicle

12. SHEAR FORCE
For max shear , load is kept such that the whole
dispersion is in span. The load is kept at 1.51/2 = 0.755m
from the edge of the beam shown below.

13. DESIGN OF SLAB SECTION AND
REINFORCEMENT
Calculation of depth
Calculation of Ast

14. DESIGN OF LONGITUDINAL GIRDER
Reaction factor

15. DEAD LOAD FROM SLAB PER GIRDER
CONSIDERING
Parapet railing
Foot path and kerb
Deck slab

16. DEAD LOAD BENDING MOMENT AND
SHEAR FORCE

17. LIVE LOAD BENDING MOMENT

18. LIVE LOAD SHEAR IN GIRDER

19. BM DLBM LLBM TOTAL BM UNITS
OUTER
GIRDER
4261 2074 6335 kNm
INNER GIDER 4261 1596 5857 kNm
SF DLSF LLSF TOTAL SF UNITS
OUTER
GIRDER
561 297 858 kN
INNER
GIRDER
561 427 988 kN

20. PROPERTIES OF MAIN GIRDER
SECTION

21. PROPERTIES :
• Area= (73 × 104) mm2
• Yt = 750 mm
• yb = 1050 mm
• I = 2924 × 108 mm4
• Zt = (3.89 × 108) mm3
• Zt = (2.78 × 108) mm3

22. PRESTRESSING FORCE
Prestressing force is calculated as per IS
1343:1980 and the prestressing force calculated is
1459 kN

23. PERMISSIBLE TENDON ZONE
Five cables are arranged to follow a parabolic profile,
with the resultant force having an eccentricity of
180mm towards the soffit at the support section.

24. CHECK FOR STRESSES AT TRANSFER
CONDITION

25. CHECK FOR STRESSES AT SERVICE
CONDITION

26. SUPPLEMENTRY REINFORCEMENT
It is provided to safeguard against shrinkage cracking.

27. DESIGN OF END BLOCK
Solid end blocks are provided at the end
supports over a length of 1.5m typically equivalent
prism based on guyons method and the bursting
tension is calculated to be 336 kN

28. CONCLUSION
Design and analysis of a prestressed post tensioned
deck slab have been carried out manually. Manual design is well
enough to ensure the safety design of the bridge deck so we
designed and analyzed it manually . The bridge deck has been
designed keeping in mind the design of bridges considering the
heavy traffic potential across India and economic design of
elements of bridge . The analysis and design of prestressed
concrete structure where performed as per codal provision of
IS: 1343-1980. Our project was completed by proper designing
of structural elements satisfying the functional, economic
requirements.

29. REFERENCES
 IS 1343-1980 Code of practice for pre-stressed concrete
 IRC: 6Road bridges std. specification and code of practice
 IRC: 18 Design criteria for Prestressed concrete road bridges
 IRC: 21 Standard specification and code of practice for road
bridges
 Ramamirutham S “ Design of reinforced concrete structures ”
Dhanapat Rai Publications, New Delhi, 2010
 Krishna Raju N “ Prestressed concrete ” McGraw
education(India) private Limited, New Delhi