Transcript Point Pleasant Bridge Disaster Group 19.ppt

Point Pleasant Bridge Disaster
Group 19
Events and consequences
5PM December 1967
46 people killed, 9 injured
Only major connection between West
Virginia and Ohio
Background
Ohio river
US highway 35
Point Pleasant, West Virginia, Kanauga,
Ohio
Two lane, 670m
American Society of Civil Engineers
Technical Background
First of its kind
Eye bars linked in pairs like a chain
Pin passed through eye
Heat treated carbon steel
Load of 4 million kg
Ultimate strength of 725MPa
Elastic limit of 520MPa
Max working stress of 350Mpa
….continued
Bedrock foundation too costly
Reinforced concrete trough 60m long and
10.2 m wide supported by piles
Shifting loads and temp. variations
40 m high pinned rocker towers
Technical factors contributing to collapse
Cleavage fracture of an eye
Minute crack when casting
Stress corrosion and corrosion fatigue
Ductile fracture near pin
South chain then snapped
Human and managerial factors
Lack of knowledge in 1927
Vindicates designer?
Not accessible for visual inspection
Bridge seemed to be performing well for
40 years
….continued
Average weight of motor car
Should have been addressed
Lessons learnt
Secretary for transport
Critical flaw sizes in bridge building
materials
New inspection equipment
Techniques for protection, repair and
salvage
Periodic inspection of all nation’s bridges