I-495 Bridge Replacement

Siefert Associates continues to provide SPS New England design services for the I-495 Bridge Replacement over the Merrimack River in Haverhill, MA. The stage 2 girder erection requires two temporary structures to support the proposed girders during erection, a North tower and a South tower. Siefert Associates designed the structures to resist the weight of the girders, and lateral loads including wind, water and ice. The structures are braced into the main trestle to increase the stiffness of the system. The image below depicts a section of the stage 2 South temporary support, members and relevant dimensions are called out.