Col­lapse points to is­sues with aging bridges

The Western Star - - OBITUARIES/WORLD -

The bridge that col­lapsed in the Ital­ian port city of Genoa was con­sid­ered a feat of engi­neer­ing in­no­va­tion when it was built five decades ago, but it came to re­quire con­stant main­te­nance over the years. Its de­sign is now be­ing in­ves­ti­gated as a pos­si­ble con­trib­u­tor to its stun­ning col­lapse.

The Mo­randi Bridge was sev­ered in its mid­sec­tion dur­ing a heavy down­pour Tues­day, killing at least 39 peo­ple.

Ital­ian pros­e­cu­tors fo­cused their in­ves­ti­ga­tion into pos­si­ble de­sign flaws or in­ad­e­quate main­te­nance of the 1967 bridge.

Engi­neer­ing ex­perts said the disas­ter points to the chal­lenges of main­tain­ing any aging bridge, re­gard­less of its de­sign.

“What the gen­eral pub­lic does not com­pre­hend is that bridges have been tra­di­tion­ally de­signed in the past for a life span of 50 years,” said Neil Hawkins, a pro­fes­sor emer­i­tus of engi­neer­ing at the Univer­sity of Illi­nois, who spe­cial­izes in re­in­forced and pre­stressed con­crete de­sign.

“The en­vi­ron­ment in which the bridge ex­ists can have a ma­jor ef­fect on how much it can last be­yond that 50-year de­sign life span.”

The struc­ture is a ca­ble stayed bridge de­signed by Ital­ian en­gi­neer Ric­cardo Mo­randi, who died in 1989. Among its un­usual fea­tures were its con­crete-en­cased stay ca­bles, which Mo­randi used in sev­eral of his bridge de­signs in­stead of the more com­mon steel ca­bles. There are two sim­i­lar bridges in the world, in Libya and Venezuela.

Ex­perts have said a num­ber of fac­tors could have con­trib­uted to the col­lapse, in­clud­ing wear and tear from weather and traf­fic that sur­passed what the bridge was orig­i­nally built to sus­tain.

“Genoa is a port city so that there can be ma­rine ef­fects and also it is a ma­jor in­dus­trial cen­tre so that there can be air pol­lu­tion that im­pairs the con­crete,” Hawkins said in an email.

“Whether any of th­ese ef­fects, or other ma­jor de­fi­cien­cies in the foun­da­tions, were present I have no knowl­edge. But all can con­trib­ute to a bridge fail­ure.”

An­to­nio Bren­cich, a pro­fes­sor of con­struc­tion at the Univer­sity of Genoa, said the de­sign lent it­self to swift cor­ro­sion and the bridge was in con­stant need of main­te­nance.

AP PHOTO

Res­i­dents are helped by fire­fight­ers as they get their be­long­ings from their evac­u­ated homes in Genoa, Italy, Thurs­day.

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