2. The objective of this study is to find out the different
problems arising while and after construction.
Moreover, We have also found remedial solutions to it.
Our objective is to give fundamental knowledge
regarding construction and maintenance of Flyover
Bridge and how to minimize the problems related with
all the functions of Flyover Bridge..
To make the roads easily accessible for day to day
traffic.
OBJECTIVE
3. Definition
A bridge is a structure providing
passage over an obstacle without
closing the way beneath. The required
passage may be for a road, a railway,
pedestrians, a canal or a pipeline. The
obstacle to be crossed may by a river, a
road, railway or a valley.
4. Components of a Bridge
The main parts of a bridge structure are
as below:
Decking, consisting of slab, girders, trusses,
etc…
Bearings for the decking.
Abutments and piers.
Foundations for the abutments and piers.
5. River training works, like revetment for
slopes at abutment, aprons at bed level, etc.
Approaches to the bridge to connect the
bridge proper to the roads on either side;
Handrails, guard stones, etc…
6. Importance of bridge
To reduce the travel time.
To minimize the congestion on roads.
To reduce the accidents arising day by day.
When the widening of road cannot be done a 3rd
dimension is to be used by constructing a flyover.
8. Reason behind going for a
flyover
As the traffic on the road goes on
increasing and we don’t have any space
left in both the dimensions, then the only
option left will be to go to the third
dimension and that is done through
flyover construction.
9. Flyover
It is a bridge that carries one road or
railway line above another either
with or without subsidiary roads, for
communication between the two.
11. At railway crossing where there is high traffic
congestion in terms of the frequency of trains
passing by or the traffic on the road, in both the
cases the flyover should be provided along the
road. Here the flyover becomes indispensable.
Railway Crossing
12. Simple Flyovers
In this case, the main road is used for fast traffic,
which is made to pass at a high level by a bridge,
providing ramps on both the approaches; and the
slow traffic is made to pass underneath. Thus the
traffics pass at two different levels, and leave no
chance for an accident.
Road Crossing
13. It requires a very large area of land. All
conflicting streams of traffic are avoided, and
so traffic can move at its own speed. This is
more advantageous than a roundabout, as there
is no necessity for weaving and slowing down
of traffic.
Cloverleaf Junction
15. Problems Arise In Different
Aspect Of Flyover
Earth work
Surplus excavated earth not leveled and neatly
dressed at the disposal place.
Less sand filling done under floors.
Proper compaction of earth under floors not done.
Compaction of earth work in filling not done as
stipulated in the contract.
Lead chart for disposal of surplus earth not
maintained.
Excavation of foundation less than specified in
drawing.
16. Concrete work.
i) Oversize/ disintegrated/soft aggregate used.
ii) Sand with more silt content used.
iii) Honey combed concrete.
iv) Concrete found bulged and not in plumb.
v) Less thickness of PCC.
vi) Proper overlaps in reinforcement not provided.
vii) Reinforcement found exposed.
viii) Lesser diameter binding wire used.
ix) Expansion joint not properly located/ provided.
x) Improper curing and compaction
xi) Timber form work used through contract provides for
steel form work.
xii) Clear cover to reinforcement not as per drawing.
17. Steel Work
i) Non-standard steel sections used
ii) Priming coat either not done or poor quality
priming coat done on steel works
iii) Tack welding done instead of continuous welding
iv) Extra slag of welding not removed
v) Thickness of sheets in rolling shutter found less
vi) Inferior quality hinges and fittings provided
vii) Steel hinges in M.S. frames not fixed by cutting
slots.
viii) Flash butt welding not done in steel windows
18. Major Problems With Bearing
Failure
Excessive Loads
Overheating
Normal Fatigue Failure
Reversal Load
Contamination
Lubricant Failure
Misalignment
Corrosion
Loose Fit
Tight Fits
20. Solutions
Excessive Loads
The solution is to reduce the load or redesign using a
bearing with greater capacity.
Normal Fatigue Failure
The remedy is to replace the bearing or consider
redesigning to use a bearing having a greater
calculated fatigue life.
Contamination
Clean work areas, tools, fixtures, and hands help
reduce contamination failures. Keep grinding
operations away from bearing assembly areas and
keep bearings in their original packaging until you are
ready to install them
21. Corrosion
Correct by diverting corrosive fluids away from
bearing areas and use integrally sealed bearings
whenever possible.
Misalignment
Inspecting shafts and housings for run out of
shoulders and bearing seats; use of single point-turned
or ground threads on non hardened shafts and ground
threads only on hardened shafts; and using precision
grade locknuts.
Tight Fits
Corrective action includes a decrease in total
interference.
23. Prevention Methods
1) Keep concrete always dry, so that there is no H2O
to form rust. Also aggressive agents cannot easily
diffuse into dry concrete. If concrete is always
wet, then there is no oxygen to form rust.
2) Stainless steel or cladded stainless steel is used in
lieu of conventional black bars.
3) A portion of the chloride ions diffusing through
the concrete can be sequestered in the concrete by
combining them with the tricalcium aluminate to
form a calcium chloro-aluminate (Friedel’s salt).
It can have a significant effect in reducing the
amount of available chlorides thereby reducing
corrosion.
24. 4) Electrochemical injection of the organic base
corrosion inhibitors, ethanolamine and guanidine, into
carbonated concrete.
5) The rougher the steel surface, the better it adheres
to concrete. oxidation treatment (by water immersion
and ozone exposure) of rebar increases the bond
strength between steel and cement paste to a value
higher than that attained by clean rebars. In addition,
surface deformations on the rebar (such as ribs)
enhance the bond due to mechanical interlocking
between rebar and concrete.
25. Literature Review
1. Jinghui Wang (et.al.2011) Presented Problems and
solutions in the protection of historical urban areas
2. S.K. Mahajan (et.al.2013) Presented New Concept of
Traffic Rotary Design at Road Intersections
3. D.M. Siringoringo (et.al.2011) Presented Vibration
Characteristics of an Overpass Bridge During Full-
Scale Destructive Testing
4. R. K. Gupta (et.al.2013) Presented Closed Form
Solution for Deflection of Flexible Composite Bridges
5. Sarfaraz Hashemkhani Zolfani (et.al.2013) Presented
Selecting the Best Design Scenario of the Smart
Structure of Bridges for Probably Future Earthquakes
6. Tehmina Ayub (et.al.2014) Presented Effect of
overloaded vehicles on the performance of highway
bridge girder: A case study
