albert bridge presentation hyder consulting

© Hyder Consulting (UK) Limited

Albert Bridge

Phil Bailey and Adam Smith


Albert Bridge


Hyder Involvement

• Review of original assessment methodology

• Ascertain and confirm as built details

• Determine the likely construction sequence and

the impact this might have on built in stresses

• Carry out a 3D Non-Linear Analysis

• Carry out local checks of the deck elements

• Develop strengthening options to bring the bridge

up to 7.5T

• Identify essential maintenance requirements.


Albert Bridge Construction

• As new neighbourhoods evolved, desire to get to Battersea Park.

• Idea originated by Prince Albert – hence the Name. Albert Bridge Company formed in 1864.

• Mr R M Ordish prepared a design based on a similar award winning bridge over the river Moldan in Prague.

• Nothing happened for a few years, as opposition from the Chelsea Bridge operators as they feared they would loose toll revenue.

• A Captain Roberts subsequently came up with a new alternative design, which was light and cheap. This was initially accepted by the directors.

• The Bill proposed in 1870, but there were major shortcomings in Roberts design.

• Bill was finally accepted with the unusual procedure of naming Mr Ordish to be designer. The Bridge was completed in 1877.



• Unfortunately The directors had previously

purchased Rope for the Captain Roberts

design, which Ordish despite his objection had

to use.

• Furthermore – the rope was made of parallel

wires, and banded at 7ft centres, but not

wrapped – as ‘was an expensive operation’.


Franz Joseph Bridge - Prague


Temporary Works

being erected


Illustration of Temporary Works



• Consequently corrosion took place soon after construction, and in 1885 tenders were sought to replace the cable with chain links as Ordish had initially requested during the construction.

• Replacement of the wire rope with steel chain system was under the instruction of Sir Joseph Bazalgette


History

• From 1906 to 1970 various committees and reports suggested the Bridge suffered from excessive movement and further works were required.

• Restricted to 2 tonne vehicles since 1960’s.

• 1972 remedial works were undertaken includingthe addition of a central pier

• Only bridge in central London not to have beenreplaced


Albert Bridge Today


New Central Pier


Suspension Saddle Bearings

• The Saddle Bearings were designed to equalise stresses in the

catenary and radial bars either side of the towers.


Pre-Assessment Investigation

• Archive drawings discovered in the basement of

the ICE

• Publications and Engineering articles from the day

including sketches illustrating the temporary

works

• Historical records including previous inspection

and assessment reports

• Site Inspections and surveys


Comparisson of Historical As-Built

and Recent Survey


Rocker Bearing Restraints

• Rocker provides

negligible longitudinal

restraint.

• Horizontal forces in the

catenary chain are

resisted directly by the

longitudinal deck

girders.

• Live loading of the

central span results in

siginificant axial loads

in the deck.


3D Analysis Objectives

• Estimate the likely development of built in

stresses during construction sequence.

• Determine whether the structure was sensitive

to geometric non-linearities.

• Carry out sensitivity analysis on New Central

Pier.

• Investigate Transfer of forces through hybrid

suspension system.


MIDAS Model


Model Detail


Construction Loads

• Superstructure was fully supported on temporary props.

• Suspension bars were also supported in order to maintain a straight profile.

• Dead loads were released following connection of the suspension elements.

• The substantial radial bars provided a direct support to the deck.

• Deck deflections following the removal of the temporary props are kept to a minimum.


No Central Pier


Central Pier with Preload in Bearings


Typical Live Load


Saddle Bearings


Special Inspection


Typical Deck Section

Douglas Fir

Jarrah Boarding

Douglas Fir

Timber Decking


Deck Soffit


Buckling Analysis


Strengthening Requirements

• Corroded Cross Girder elements to be replaced in

order to restore adequate capacity


Strengthening Requirements

• Longitudinal Girders to receive localised

strengthening/ repairs where necessary in the form of

additional plates on the top and bottom flanges


Deck Timbers

• Footway Timbers to be strengthened with an additional support in order to resist Accidental Wheel Loading.


Refurbishment Works

• Rotting Deck Timbers to be replaced where necessary

• Waterproofing and Drainage System to be renovated and improved in order to prevent further deterioration of the under deck elements

• Repainting Structure

• Bearings deck supports to be renovated

• New Lighting System


Conclusion

• We have found during our analysis that due to the construction and form of the Albert Bridge it is not sensitive to geometric non linearities.

• A rigorous review and analysis has meant that strengthening requirements have been minimised and better placed.

• Refined analysis of the U-Frame behaviour was key in identifying residual capacity.

• We are presently finalising our analysis to identify areas that require strengthening.

• Contract to strengthen and refurbish the bridge to be let at the end of the year.

• Completion by Olympics 2012

albert bridge presentation hyder consulting

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