Grand Conceptor Award – HNTB Corporation, Kansas City

Firm Name: HNTB Corporation, Kansas City

Project: Iowa City Gateway – Park Road Bridge

Client: City of Iowa City

Dubuque Street and Park Road are key transportation links providing access to Iowa City’s business district.  The Park Road bridge provides a connection from Dubuque Street to the University of Iowa campus and the new Hancher Auditorium.  This area has a history of flooding that results in frequent road closures. This project is part of a master plan to address the impacts of regional flooding and provide enhancements to the transportation corridor.  Key goals included reducing closures due to flooding, improving user access, and providing a new aesthetic Iowa River crossing at Park Road. The selected structure type consists of a unique three-span, concrete, partial-through tied-arch bridge. This bridge is composed of a continuous post-tensioned tie girder supporting transverse post-tensioned floorbeams and a mildly reinforced concrete arch. Design of the aesthetic structure did not come without challenges.  The unique framing of the bridge caused some unexpected structural behavior due to thermal loading.  HNTB’s innovative solution was to impose a vertical load at the abutments during erection to help counteract the tension forces in the deck.