The presentation is about cantilever bridge construction and its techniques and a case study in the end.

1. CANTILEVER BRIDGE CONSTRUCTION
PREPARED BY
KUNDAN SAHADEV SANAP
SEAT NO. 202030016
VJTI, MATUNGA

2. TABLE OF CONTENT
• Introduction about Bridge
• Types of Bridges
• Cantilever Bridge
• History of Cantilever Bridge
• Types of Cantilever Bridge
• Method of Bridge Construction
• Advantages of Cantilever Bridge
• Disadvantages of Cantilever Bridge
• Case study- Wilson Creek Bridge, South west Virginia
• Form Traveller System

3. INTRODUCTION
• A bridge is a structure built across an obstacle such as a body of water, valley
or road for the purpose of providing a passage over the obstacles.
• Design of the bridge varies depending on the function of the bridge and the
nature of the terrain where the bridge is to be created.

4. TYPES OF BRIDGES
• Arch Bridge
• Beam Bridge
• Cable stayed Bridge
• Truss Bridge
• Suspension Bridge
• Cantilever Bridge

5. CANTILEVER BRIDGE
• A bridge built using cantilever structures that projects horizontally into space,
supported on only one end.
• There are some special conditions where the number of supports cannot be
given, in that case, Cantilever Bridges are suitable
• For small footbridges, the cantilevers may be simple beams; however large
cantilevers bridges are designed using trusses.
• Cantilever bridges should be able to resist tensile stresses in the upper
support and the compressive stresses in the lower support.

6. CANTILEVER BRIDGE (CONTD.)
• In some cases the length between two supports where Bridge has to be
constructed it is very long which cannot be spanned by one cantilever on
each side.
• In such a situation, the special Beam Bridge or truss Bridge is placed between
the arms of two cantilever which connects them into one Bridge. The type of
bridge is known as Suspended Span Bridge.

7. HISTORY OF CANTILEVER BRIDGE
• First cantilever bridge appeared in 19th century when there was a need for
longer bridges.
• To solve the problem of length, engineers of that time found out that many
supports would distribute the loads among them and help to achieve length.
• The one to be the first to invent and patent a cantilever bridge was Heinrich
Gerber which did it in 1866.
• Hassfurt Bridge over the Main River in Germany.

8. TYPES OF CANTILEVER BRIDGES
On the basis of method of construction
• Balanced Cantilever Bridges
• Continuous Cantilever Bridges

9. TYPES OF CANTILEVER BRIDGES (CONTD.)
• Balanced Cantilever Bridges
• most efficient methods of building bridges
• It does not require false work for construction.
• This method has great advantages as compared
to other forms of construction in urban areas,
• where temporary shoring will disrupt traffic and
services
• In the deep valleys below and on waterways
where false work are not only costly but also a
hazard.

10. TYPES OF CANTILEVER BRIDGES (CONTD.)
• Balanced Cantilever Bridges
• Construction begins at the permanent piers
and proceeds mid-term in a balanced
manner as shown in fig.
• The structure is hence self-supporting at all
stages.
• The construction may either be cast-in-situ
or can be precast.

11. TYPES OF CANTILEVER BRIDGES (CONTD.)
• Continuous Cantilever Bridges
• The bridge was constructed using
two gantries from the opposite end
(abutments) which met in the center
to complete the structure.
• In order to compensate for the
absence of balance cantilever,
abutments are made extra heavy.

12. METHOD OF CONSTRUCTION
• Cast-in-Situ Method
• Suitable for Short bridges
• Time consuming
• Types-
• Incremental launching method
• Balanced cantilever method
• Cast-in-Situ Post tensioned method

13. METHOD OF CONSTRUCTION
• Cast-in-Situ Method
 Steps
• Construction of lower infrastructure of the bridge i.e. abutment, piers, etc
• Erection of ground supported staging
• Casting the segments
• Dismantling of staging

14. METHOD OF CONSTRUCTION
• Precast Segmental Method
• Suitable for Long bridges
• Economical for multiple nos. of span
 Steps
• Casting of Precast Segments in casting yard
• Transporting the precast segments at the site
• Erection of Precast segments using launcher or crane
• External Pre-stressing
• Grouting

15. ADVANTAGES OF CANTILEVER BRIDGE
• False-work is not required
• Suitable for longer span
• Support is required only on one side of its cantilever.
• As due to the absence or less no’s of piers in between the abutments, a wide
passage gets available.

16. DISADVANTAGES OF CANTILEVER BRIDGE
• Cantilever bridges have to take care of its stability by balancing between
compressive as well as tensile forces acting on it.
• Cantilever bridges are heavy, so it required larger and stronger support.
• Not suitable for Earthquake Prone Area
• Construction and the Maintenance of the Cantilever bridges are complex.

17. CASE STUDY
• Wilson Creek Bridge- Southwest Virginia, US
Construction Phase
After Completion

18. CASE STUDY
• Wilson Creek Bridge- Southwest Virginia
Side - Elevation of Wilson Creek Bridge
• Total length- 605m (Divided in Five spans) and Width- 12m
• Three center spans-144m & two side spans of 86.5m each.
Abutment B
Pier 1 Pier 2 Pier 3 Pier 4
Abutment A
86.50 m
144.00 m
144.00 m
Wilson
Creek
Wilson Creek Bridge
86.50 m 144.00 m
Ellet Road

19. BRIDGE & ITS FEATURES
• Wilson Creek Bridge- Southwest Virginia, US
• Location- It is in Montgomery County which is located in Salem District,
which comprises twelve counties in the southwestern part of Virginia.
• The bridge will be crossing Wilson Creek and Ellet Road (Route 723) in Ellet
Valley.
• It’s a cast-in-place Segmental Balanced Cantilever bridge.
• The bridge superstructure consists of a single box girder with cantilevering
flanges. It has a varying depth that reaches its maximum at the piers.
• Piers are hollow cast-in-place shafts with a vertical taper.
• Both abutments rest on footings that are 4.05 m long, 12.00 m wide, and on
average 1.30 m deep.

20. PARTIES INVOLVED
• Owner- Commonwealth of Virginia Department of Transportation (VDOT).
• Design for bidding purposes- Figg Engineers, Inc. of Tallahassee, FL.
• Preparation of Drawings- Janssen & Spaans Engg, Inc. of Indianapolis, IN
• Consultant- PCL Civil Constructors, Inc. of Coral Springs, FL (PCL).

21. CONSTRUCTION SEQUENCE
• Site preparation- Cleared the trees and shrubs and completed grubbing.
• Foundation Construction, Drainage & Earthwork
I. Excavation- Drilling & Blasting
II. Foundation
III. Earthwork filling up to 1 m
• Substructure Construction- By traditional method
I. Abutments
II. Pier shafts

22. ERECTION SEQUENCE
• Actual order- From higher level to lower level
Pier 2 - Pier 3 - Pier 4 - Pier 1
Dimensions Pier 1 Pier 2 Pier 3 Pier 4
Height (from footing top to girder
bottom)
24.524 m 41.314 m 38.514 m 25.943 m
Top width 6.000 m
Top depth 3.750 m
Bottom width 6.982 m 7.654 m 7.542 m 7.040 m
Bottom depth 4.978 m 5.818 m 5.678 m 5.050 m

23. ERECTION SEQUENCE
Construction Phase 1
Erection of segments by means
of Form Traveler on BHS of
Pier 2
Construction Phase 2
Erection of segments by means
of Form Traveler on BHS of
Pier 3

24. ERECTION SEQUENCE
Construction Phase 3
Erection of segments by means
of Form Traveler on BHS of
Pier 4
Construction Phase 4
Erection of segments by means
of Form Traveler on BHS of
Pier 1

25. FORM TRAVELER
• Modern Technique for Bridge Construction.
• It is a formwork that builds a bridge by moving on the bridge itself.
• Long span bridges like cable stay and Long cantilever Bridges are
constructed most efficiently by balanced cantilever method by using FORM
TRAVELLERS.

26. THE END !!!