Sydney Harbour Bridge Analysis

This assignment delves into a detailed analysis of the Sydney Harbour Bridge's structural design. It examines critical elements such as the bridge's hydraulic system, which accommodates thermal expansion and contraction, and its hinge-type footing system designed to withstand steel expansion. The analysis also highlights the bridge's exceptional load capacity due to the generous use of materials and its vulnerability to corrosion, necessitating regular painting for longevity.

Harbour Bridge
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Structural analysis

Harbour Bridge
Contents
Introduction......................................................................................................................................3
Annotation.......................................................................................................................................4
Live Loads.......................................................................................................................................4
Principle Structure...........................................................................................................................4
Plan and elevation............................................................................................................................4
Principle structure............................................................................................................................5
Material Used...................................................................................................................................5
Bending, Tension and compression.................................................................................................6
Critical connection...........................................................................................................................6
Footing system.................................................................................................................................7
Serviceability...................................................................................................................................7
Bibliography....................................................................................................................................8
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Harbour Bridge
Introduction
This project will analyse the one of the remarkable man made structure, named as Harbour
Bridge situated in Sydney, Australia. People has gain much knowledge through research and
development, but this structure was made at that time when knowledge about making such
structure at an early stage. When behaviour of any made structure was merely predictable. The
thought about and safety is not a serious concern and factor of safety were taken as 2.5 times of
the capacity.
It is
not enough to say that there are very few bridges in world that has property similar to the
Harbour Bridge Sydney. Some of the important historical and important facts are as follows.
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Figure 1 Annotation diagram of Harbour Bridge

Harbour Bridge
Annotation
 It was planned about 100 year earlier than when it was started. This was proposed by Francis
Greenway, after 100 year his proposal was initiated by chief engineer John Bradfield in
1912. It was again halted due to World War I, and in November 1922, this was legalised to
make bridge by the parliament of New South Wales. This was made to connect central
business district to north shore of Sydney. But it is considered as a land mark of Sydney, this
is one of the visitor points in Sydney. The making arch type design is started by the roman,
but in this bridge, the arch is taken from upper side, this was done to keep in mind that the
ship and other small water vehicle can easily pass through this bridge. From calculation and
practical point of view the ship is completely balanced. All the permanent or load are
equally distributed in four bearing which is mounted with the pylon. Only steel in this bridge
and especially arch of this bridge is about 40000 tonnes heavy, and its total weight including
deck and rope is around 53000 tonnes. This was designed on the factor of safety of 2.5 at
that time. Each of the bearing can withstand the load of 200,000 KN of load. Except this
arch and bridge rest of weight is very less (university, 2014).
Live Loads
 The live load of this bridge consists of Tram, rail, four wheeler and pedestrian. The width of
this bridge is around 50 meter, As per Australian standard it has 13 lanes extreme four lanes
in one side is for tram and rail, rest for pedestrian and four wheeler. After adding the safety
factor about 140000 KN of given by live loads on this bridge, and after combining the dead
load it becomes 670000 KN of total load which still less that its rated capacity (Taratori,
2008).
Principle Structure
 This bridge is arch type hinged arc two points. The deck is placed in such a way that its
directly hags from the arch, made rigid with trusses across the spans, and this spans with
arch is hinged with pylon at the sides of the bank, according to an estimate about 60% of
steel work is done for dead load, 30 % for live load and 5 % for thermal and wind pressure
separately
Plan and elevation
This is the required figure, all the dead load passing through beams area going to bearing
the pylon
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Harbour Bridge
Principle structure
 Except pylon al the frame are open across the direction, the design of the deck is thin and its
lower side is also consists of frame of small beams, this design is appropriate for withstand
the wind load in particular that area. Since the land breeze and sea breeze are passing across
the frames, there no hindrance for air in bridge.
Material Used
 Two important material used in this construction is coke concrete and silicon steel. The use
of coke concrete is due to low in price and easily available within 25 km. The design of the
bridge provides compressive force to the bearing in this condition some low quality bu
acceptable concrete can be used.
 The second and most widely used material is Silicon steel, if we see the microstructure of
silicon steel then we will analyse that it has solid solution. It has 0.38% C steel, It
composition is 52% ferrite and 47% pearlite. Pearlite naturally stronger, harder and tougher
that pearlite, so it provide strength to the structure, whereas pearlite provide rigidity to the
structure.
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Harbour Bridge
Bending, Tension and compression.
 The design of this bridge is so simple that it can easily identified by any person about its
working system, The bending moment is taken by the arch, The tension part is covered by
the rope with which deck is attached and compression takes place at bearing section which is
provided in the phot
The diameter of the pin if the hinge is 398 mm and it is 4.2 m long
Critical connection
 The critical connection of the bridge is connection at the hinge; another critical connection is
its hydraulics system which is used to withstands the thermal extension and compression of
the bridge. In hot day the bridge can
expand up to 160 mm. to adjust this
expansion and contraction hydraulic
system is provide near thrust bearing, this
system allows the bridge to expand up to
400 mm. which is quite larger than its
normal expansion.
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Harbour Bridge
Footing system
 The footing system is providing is hinge type. The
used of hinge type footing system is due to its
material which steel, it is expansion can damage
the fix footing system, in order to nullify the
mending moment about the its end is necessary to
keep on hinge.
Serviceability
 One hidden point about this bridge is that this bridge can handle much more weight todays
bridge, this use due to the reason that lot of extra material is being used in building this
structure. In order to making the structure fool proof, the engineer were enforcing extra
material, because they are not sure that it will be stable or not
 Any steel bridge is vulnerable to corrosion, it this bridge is painted regularly it can service
quite long time. Except road bed, there is nothing in this bridge which can take wear and
tear. So it is useful for much longer time.
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Harbour Bridge
Bibliography
Andrew Pytel, J, K., 2001, Engineering Mechanics: Dynamics. 2nd ed. london: Thomson
Learning.
Banisch, S, 2016, Markov Chain Aggregation for Agent-based Models. 1 ed. Leipzig: Springer
Verlag.
BD-090, C, 2017. Australian Standard Bridge design: AS 5100.7:2017, Sydney: Standard
Australia.
Dunn, D, 2011, Complex Stress. MECHANICAL PROPERTIES OF MATERIALS, 1(3), pp. 1-22.
Gere, J, 2014, Mechanics of Materials, Brief Edition. 4th edition ed. Stamford: Cengage.
Hartog, J, P, D., 2012. Strength of Materials. 8th ed. New York: Dover Publication.
Hibbler, 2010. Engineering Mechanics: Combined Statics & Dynamics. 12th ed. London:
Prentice Hall.
J, L, Meriam, L. G. K., 2012. Engineering Mechanics: Dynamics. 7th ed. Denever: John Wiley.
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Harbour Bridge
Taratori, S, 2008. CRITICAL ANALYSIS OF THE DESIGN AND CONSTRUCTION. Bridge
Engineering 2, 1(1), pp. 1-10.
university, b., 2014. SydneyHarbour.html. [Online]
Available at: http://www.bristol.ac.uk/civilengineering/bridges/Pages/NotableBridges/
SydneyHarbour.html
[Accessed 15 10 2017].
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