Falling temperatures during a major concrete pour are thought to have contributed to the collapse of a bridge under construction in Andorra on Saturday.
Five people died and six were injured in the accident which happened just before 12pm on Saturday morning during a 1,200m3 concrete pour.
Shortly before noon, when around 500m3 of concrete had been placed, either the formwork or falsework system gave way, tipping a 20m long formwork section and 11 workers onto the valley floor 5m below.
Nine of the workers were from Portuguese contractor Ambicepol and two were from concrete supplier Uniform.
“The weather got colder while the concrete was being poured.”
Jolyon Gill, independent bridge consultant
Temperatures in the mountain state on the French-Spanish border dropped rapidly during Saturday, a factor which engineers said might have contributed to the failure.
“The weather got colder while the concrete was being poured,” said independent bridge consultant Jolyon Gill.
“The beams could have pulled back from the bearings. It looks like the supporting trestles either moved through temperature or subsidence. The weight of the concrete was the last straw.” There were around 35 workers on site at the time of the collapse.
They were employed by the numerous companies involved in the bridge construction. This includes Spanish contractors Dragados and Dragasa, Paj, Mou Land, Support, CD-Casado Carlos Fernandez, Payma Pyrenees and Gaén. RMD provided the falsework and formwork.
The bridge links with the Dos Valires tunnel project which will link the towns of Encamp and La Massana. Work is due to finish next year. The structure comprises a cable stayed main bridge exiting from the west entrance of the tunnel feeding onto an elevated roundabout. It was part of this roundabout structure which collapsed during the pour.
The project is being carried out by the central Government of Andorra’s interior ministry. “The police and the government have started their investigations,” said an Andorra government spokesman.