A tragic scene has no doubt unfolded?ÿwith the collapse of a major arterial viaduct in Genoa, Italy.?ÿ First I want to offer my personal prayers for the victims, their friends and families.
I was first drawn to a news article with a headline reading "Heavy Storm Causes Bridge Collapse".?ÿ?ÿ Of course once I began ejucatin' myself with the available data it became apparent a storm probably had little to do with the collapse in a direct sense, unless the pier system was compromised by flood waters.
Second I was surprised to see the bridge?ÿappeared to be a (modern design) pretty typical reinforced concrete structure as opposed to steel truss.?ÿ And I did read the bridge was undergoing some level of repairs while still under traffic.?ÿ One photo of the resultant debris looked as if almost every vehicle was a tractor-trailer.?ÿ I wonder if slowed traffic due to the storm and/or construction created uneven or critical loading.
I guess we'll eventual get to read more details.?ÿ Even though this is half a world?ÿaway it could be a lot closer to home but by the Grace of God.?ÿ?ÿThe aging infrastructure in the U.S. is apparent to those of us that find ourselves under some of these bridges.?ÿ The view from underneath is far more revealing than a trip over the bridge deck at 60 mph.?ÿ
I've talked with my brother, another?ÿ engineer, who saw a news reporter where a first hand witness saw lightning strike a tower and the first section collapse. Because of the linking of bridge sections, other parts have since collapsed. The bridge is mainly over an industrial area but there was a street of residential buildings under one collapsed section. I wondered why the bridge was so high above the surrounding terrain, but saw on Google Earth that is approached by tunnels from both directions. What I wonder about most is if remaining sections have to be demoed before reconstruction can begin. The majority of the span is over rail yards and industries.
Fatality count is high. Bridge is 50 years old and was undergoing repairs. Most likely a 50 year design life span. I would not doubt it was not designed for the truck loads it has been seeing.
Paul in PA, PE, PLS
