Ontario’s Ministry of Transportation has brought in the National Research Council of Canada to help determine the cause of last week’s major mechanical failure at the new Nipigon River Bridge.

The bridge was temporarily completely closed following the sudden bolt failure, which resulted in the western edge of the cable-stayed span rising by about 600mm at the expansion joint (link opens in new tab). The bridge was subsequently reopened to single-lane traffic after the deck was brought back into alignment.

The research and technology organisation will investigate the problems with the bridge, which is a key connection in the Trans-Canada highway. Specialists will analyse some of the damaged bolts and take them to Ottawa for further testing. Failure analysis will be carried out on the bolts used to hold together two sections of the cable-stay bridge. Work will begin with fracture surface evaluation as well as tests on the metallurgical composition and verification of mechanical properties to check conformity with ASTM standards.

“We are pleased to work with Ontario's Ministry of Transportation to analyse the conditions that led to the bolts' failure on the Nipigon River Bridge,” said Richard Tremblay, general manager of construction at the National Research Council of Canada. “The National Research Council is deploying its best industry-leading experts in materials analysis and critical infrastructure and advanced equipment to arrive at a timely, safe, and lasting solution for Canadians using this important trade corridor.”