0410_Paddington-Brunel LoBEG-Oct04-Presentation_Javad_Akhtar

© Hyder Consulting

Paddington LTVA Bridge Project

- Discovering Brunel

Javad Akhtar

Jo’ Kenward

Bal Chana

22 October 2004

© Hyder Consulting

Isambard Kingdom Brunel – The Man

• 1806 – 1859

• Born in Portsmouth

• Son of Sir Marc Brunel

© Hyder Consulting

Brunel – Career Snapshot

• 1826 – Thames Tunnel

• 1831 – Clifton Bridge

• 1833 – Engineer to Great Western Railway

• 1837 – PS Great Western Launched

• 1847 – Atmospheric railway opens Exeter - Teignmouth

• 1854 – Paddington New Station opens

• 1859 – Died aged 53. Chains from Hungerford Bridge

used on Clifton suspension bridge in his memory.

© Hyder Consulting

• 1838-39 Paddington canal Bridge

• 1841-5 Hungerford pedestrian.

• 1846 Usk Viaduct Newport

• 1850-52 Wye Rail

• 1854-8 Royal Albert, Saltash

• 1864 Clifton Suspension

Brunel – Iron Bridges

© Hyder Consulting

Paddington LTVA - London

• New Bridge over 15 rail

tracks and canal

• Replacement for existing

with increased capacity

• Hyder involvement since

1998

© Hyder Consulting

Paddington LTVA – Options

• Bridge Closure

• Bridge Form

• Construction

methodology

• Procurement options

© Hyder Consulting

Paddington Programme

• 1998 – 2000 Design options and strategy

• 2000 – 2001 Procurement and scheme development

• 2002 Advance Works, tendering & design

• 2003 Design and service diversions

• August 2003 start of main works not requiring closure

• Bridge Closure 11th January 2004

• Early January 2004 programme modified to accommodate

careful dismantling of Brunel Bridge

• Completion of main bridge replacement – spring 2006

© Hyder Consulting

Layout of existing structures before work commences

1

SOUTH

ABUTMENT

BOWSTRING ARCH

PIER 10/11 LUL

NORTH

ABUT.MASONRY ARCHES CANAL

Stage

© Hyder Consulting

1. Raise the existing bowstring arch bridge by

approximately 10m in to the air

2. Construct the support structures for the canal

bridge including a reinforced earth abutment and

piled foundations with concrete supports

5Stage

2

22

1

© Hyder Consulting

1. Construct the rail bridge deck phase 2

2. Install a restraining system at the rear of the rail bridge to

stop the bridge from sliding forward when launched

10Stage

1

2

© Hyder Consulting

1. Complete road construction

2. Open road

15Stage

© Hyder Consulting

Brunel Bridge

• Mid 2003-Construction programme planned to demolish existing

bridges along including Canal Bridge

• Dr.Steve Brindle from English Heritage researching material for

Paddington station uncovered Brunel’s note book, sketches for

canal bridge.

• Site visits revealed that the bridge Brunel referred to was the

Canal Bridge at Paddington.

© Hyder Consulting

Brunel Bridge

• English Heritage commissioned trial pits to be dug on site in

August 2003 to verify the Brunel notes.

• Records show that it probably the first iron bridge built by Brunel.

• The bridge is a two span structure of 10.7m (35ft) and a side

span of 4.9m (16ft).

• The girders are of unusual x-section, lower flange a heavy bulb

tee, a thick web and a solid bulb for upper flange. Each 35ft

beam weighed 20 tons.

• The trial pits confirmed that the Canal Bridge was indeed the first

cast iron bridge designed and constructed by Brunel in 1838-39

© Hyder Consulting

Brunel Bridge

© Hyder Consulting

Brunel Bridge

• Unique design; use of cast iron possibly due to tight headroom

requirement and large span. Wrought iron has greater tensile

strength but may require deeper beams.

• Brick arch would have added too much height leading to a

steeper gradient to Harrow Road

• Brunel load tested 35’ beams to 20,25, & 30 tons; the 16’ girders

tested to 30 tons

• Items fitted like a jigsaw; no bolted connections; shaped ends

and wedges used to hold beams together.

© Hyder Consulting

Brunel Bridge

• Load assessment carried out in august 1998. No drawings

available. Information obtained from trial pits and site surveys.

• Not withstanding the shallow arch shape, actual structural

behaviour was as simply supported beam.

• Load restriction imposed in 1999 as bridge assessed capable of

only 7.5 tonnes capacity.

• Brunel’s simple beam test results demonstrated a higher capacity

than the modern assessment. Exact details of the testing are not

known.

0410_Paddington-Brunel LoBEG-Oct04-Presentation_Javad_Akhtar

Documents

Transcript of 0410_Paddington-Brunel LoBEG-Oct04-Presentation_Javad_Akhtar