By DANICA COTO

Associated Press

Bridge_No._122

SAN JUAN, Puer­to Rico — Puer­to Rico’s salty ocean air is cor­rod­ing dozens of bridges across the U.S. ter­ri­to­ry, con­tin­u­al­ly weak­en­ing the struc­tures and pos­ing a chal­lenge for offi­cials try­ing to pri­or­i­tize which ones to repair first.

The island has 31 bridges con­sid­ered frac­ture crit­i­cal and struc­tural­ly defi­cient, accord­ing to a review of fed­er­al data by The Asso­ci­at­ed Press. The frac­ture crit­i­cal des­ig­na­tion means those bridges have no redun­dant pro­tec­tion and could col­lapse if just one vital com­po­nent fails.

Javier Ramos, direc­tor of Puer­to Rico’s Road Author­i­ty, said that while offi­cials are plan­ning to fix all 31 bridges, they are still safe and that he would have closed them if they were not.

He said the major­i­ty of those bridges need to have their con­crete slabs replaced, as cor­rod­ing met­al rods are snap­ping and weak­en­ing their struc­tures.

“We live in a trop­i­cal island,” he said. “Regard­less of how close or far away we are from the ocean, that salty envi­ron­ment is present in any cor­ner of the island.”

The 31 bridges are part of some 7,795 bridges in the U.S. that are both frac­ture crit­i­cal and struc­tural­ly defi­cient, a com­bi­na­tion that experts say is espe­cial­ly prob­lem­at­ic.

The Asso­ci­at­ed Press ana­lyzed data involv­ing 607,380 bridges in the Nation­al Bridge Inven­to­ry, which are sub­ject to Nation­al Bridge Inspec­tion Stan­dards. On a nation­al basis, there are 65,605 struc­tural­ly defi­cient bridges and 20,808 frac­ture crit­i­cal bridges, accord­ing to the most recent­ly avail­able fed­er­al gov­ern­ment data.

“Puer­to Rico has rel­a­tive­ly few struc­tural­ly defi­cient high­way bridges as com­pared to some states,” said Pedro Pier­luisi, Puer­to Rico’s rep­re­sen­ta­tive in the U.S. Con­gress.

He said the Fed­er­al High­way Admin­is­tra­tion allo­cates $150 mil­lion a year to Puer­to Rico’s Depart­ment of Trans­porta­tion, which has the flex­i­bil­i­ty to decide what amount will be used to repair bridges.

Ramos said up to $30 mil­lion is allo­cat­ed a year to bridges, with crews repair­ing an aver­age of five to sev­en bridges annu­al­ly.

The 31 bridges in Puer­to Rico make up a mix of urban and rur­al struc­tures, and all are locat­ed near or above rivers or creeks in the island’s coastal and cen­tral regions.

Ramos said the biggest clus­ter of bridges in need of repair is in the cen­tral moun­tain town of Utu­a­do, in an area of heavy rain­fall.

Over­all, Puer­to Rico has 2,270 bridges that author­i­ties inspect every two years. As a result of the inspec­tions, offi­cials closed a bridge in the south­ern town of Guayanil­la last year after not­ing that its con­crete slabs were crum­bling fol­low­ing heavy rains. Some of Puer­to Rico’s old­est bridges, how­ev­er, are still being used. They include the his­toric Mav­il­la stone bridge in the cen­tral town of Corozal that was built in 1900.

Ramos said one of the first bridges that offi­cials plan to deal with is in the east­ern coastal town of Naguabo.

It’s a steel truss bridge that will be replaced, not repaired, he said. He added that author­i­ties already post­ed a sign warn­ing the bridge can hold only up to 5 tons of weight.

Ramos said part of the prob­lem is that most of Puer­to Rico’s bridges were designed some four decades ago and built to with­stand only up to 20 tons of weight. The weight of trucks car­ry­ing goods has since increased to some 55 tons, he said.

“We have bridges that have exceed­ed their lifes­pan,” he said.

Author­i­ties also are prepar­ing to fix anoth­er bridge in Naguabo start­ing next year, and two bridges in the south­ern town of Yau­co are already sched­uled for ren­o­va­tions. Ramos said that on those bridges crews will use geosyn­thet­ic rein­force­ment soil, a mate­r­i­al that is afford­able, easy to main­tain and allows projects to be built quick­ly.

“Any bridge that is on the list requires imme­di­ate or short-term atten­tion,” Ramos said. “It doesn’t mean it presents an immi­nent dan­ger. If that were the case, we would obvi­ous­ly take the deci­sion to close it.”