Proposed Bridge over the Preston River in East Bunbury, Western Australia
Kyawt Yamin Thwin -700020607 Khant Htut Lwin -700020600
Toe Myint Naing -700020605 Anthony Mak Chao Jun -700014760
Project Background
A new bridge is required to replace an existing bridge which crosses
over the Preston River in Bunbury, Western Australia. The prosed
bridge types is cable-stayed bridge.
Key objective and client’s intent
• to optimize between the bridge aesthetics and the
construction cost and time.
• Minimis environmental impact
Relevant Standards and Design Specification
• AS 3600_2018: Austria Standard Concrete Structure
• AS 5100.1_2017: Austria Standard: Bridge Design: Scope
and General Principles
• AS 5100.2_2017: Austria Standard: Bridge Design: Design
Loads
• AS 5100.5_2017: Austria Standard: Bridge Design: Concrete
Construction method
Preliminary Drawing
Site preparation
1. Demolition
2. Removing asbestos
3. Site Clearing
4. Site surveying and set out
5. Earthwork
Substructure
1. Initiate the caisson system
2. Pump out water
3. Drive piles into the ground according to design
4. Assemble footing according to design.
5. Erect piers to designated level.
Superstructure
1. Erect pylons and girder simultaneously fixing it to the piers.
2. Initiate balanced free cantilevering system using derrick cranes
3.
Install stay cables stressing it to relieve the bending moments in
the girders
4. Install final stay cables
Item Detail Justification
Bride span 66 meters • Estimated from Google Maps.
Bridge type Cable-stayed Bridge • Less steel cable, faster to build n incorporate more precast concrete section
• Higher stiffness and display smaller deflections than suspension bridges
Pylon 12 m • Optimal Height of pylon that can comply with 0.25 𝑙
• The higher the tower above the road level, the lower the cable forces and the
required quantity of cable steel.
2 number • A single tower design cost more and the height of tower need to be higher than that
of twin tower. Single tower height of pylon must comply with 1.8 𝑙
20 m from left edge • The side span of the cable stayed bridge shell be about 0.42 time that of the main
span.
• Pylon was in the between of the main span 46m and the side span 20m.
Cable Semi-harp shape cable configuration • The structure’s aesthetics is really pleasing
3 numbers at each tower • to reduce the bending moments of the beam
• decrease the individual cable forces to be anchored.
15m c/c on deck • By adjusting the angle of the stay (α) nearer to the pylon, the required stay cables
size will decrease, and the height of pylon will increase
1 m c/c on tower • To develop semi-harp shape arrangement of cables
• Easy to maintain
Footing Pile footing • Drilled pile footing
• Pile cap
Preliminary design
Cable Cable Force (P) No. of stands
Cable 1 3153.55 kN 67 nos
Cable 2 5256.02 kN 111 nos
Cable 3 6713.74 kN 142 nos
Construction cost
Specifications Total cost Cost per Area Price Index
2020
Cost per Area
(Proposed Bridge)
Total Cost 2020
ANZAC Bridge
(Pyrmontm,
New South
Wales,
Australia)
Width: 32m
Length: 805m
Longest Span: 345m
Year of Complete: 1995
AUD 170 million AUD 6,599.38 260% AUD 17,142.16 AUD 18.1 million
Eleanor
Schonell Bridge
(Dutton Park,
Queensland,
Australia)
Width: 20m
Length: 390m
Longest Span: 183m
Year of Complete: 2006
AUD 56 million AUD 7,179.49 142% AUD 10,195.10 AUD 10.8 million
Reference:
“Design and Analysis of Cable Stayed Bridge” 2017 -Murkute U.T.
“Cable Stayed Bridges With Prestressed Concrete”- Fritz Leonhardt
Project Timeline