Firm earns ACEC award for work on Tanana River Bridge

Hanson Professional Services, Inc., earned a National Recognition Award for exemplary engineering achievement in the American Council of Engineering Companies' (ACEC) 49th annual Engineering Excellence Awards for the Tanana River Bridge in Salcha, Alaska.

Located in a remote area with potentially active seismic faults, the 20-span, 3,300-ft. long crossing is Alaska’s longest bridge and part of the Alaska Railroad Corp.’s Northern Rail Extension. Engineers had to account for a complex mix of site conditions, including wind, water pressure, river bed scour, sheet ice, flooding and driftwood jams, as well as temperature extremes from 90 degrees in the summer to wintertime lows of nearly 70 degrees below zero.

Extensive hydraulics modeling, including a 3-D physical model, helped the project team assess how these conditions might affect the structure and refined the design accordingly. The project also included construction of a levee to protect Salcha residents from the river’s annual floods.

The project is among 170 engineering projects throughout the nation and around the world recognized by ACEC as preeminent engineering achievements and eligible for one of the top 2015 Engineering Excellence Awards. Judging for the Engineering Excellence Awards took place in February and was conducted by a panel of more than 30 engineers, architects, government officials, media members and academics. Awards criteria include uniqueness and originality, technical innovation, social and economic value, complexity and success in meeting goals.

The Tanana River Bridge was completed last summer and features a bimodal deck that can accommodate both rail and road traffic. The project was also named a finalist for Bently Systems’ “Be Inspired” awards in the category “Innovation in Bridges.”