THE CONCRETE BRIDGE MAGAZINE

Spring 2019

ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.

Issue link: http://www.aspiremagazinebyengineers.com/i/1093138

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Built in 1940, the original Maine– New Hampshire Bridge spanning the Piscataqua River between Portsmouth, N.H., and Kittery, Me., served as the critical backup route between Maine and New Hampshire if traffic were disrupted on the Interstate 95 Bridge upstream. In 1987, the Maine–New Hampshire Bridge was renamed to honor Sarah Mildred Long, an employee of the Maine–New Hampshire Interstate Bridge Authority for 50 years. Three decades later, on March 30, 2018, a replacement bridge, also named for Long, opened. Its innovative design would have made her proud. The previous structure had five main truss spans, including the vertical lift span, along with 15 roadway spans on the Portsmouth side and seven on the Kittery side. The new Sarah Mildred Long Bridge has twin segmental- concrete approach spans in a stacked configuration leading to a single-deck hybrid movable span at its center. The new structure's design, which provides a unique concept for a segmental bridge, improves the skew angle and width of the navigation span as well as safety and efficiency for vehicles, rail lines, and maritime vessels. With the new bridge, maritime vessels can navigate the Piscataqua River while the upper segmental- approach superstructure carries U.S. Route 1A (Bypass) and the lower segmental superstructure connects Pan Am Railways, a railroad system for the Northeastern United States, to the Portsmouth Naval Shipyard. The movable hybrid span rises to allow passage of tall vessels and lowers to railroad-track level for trains to cross, remaining at the vehicle level in its resting position. The Portsmouth, Me., approach spans extend over Market Street and the Pan profile SARAH MILDRED LONG BRIDGE / PORTSMOUTH, NEW HAMPSHIRE, AND KITTERY, MAINE BRIDGE DESIGN ENGINEERS: FIGG Bridge Engineers, Tallahassee, Fla., and Hardesty & Hanover, New York, N.Y., a joint venture PRIME CONTRACTOR: Cianbro, Pittsfield, Me. POST-TENSIONING CONTRACTORS: GZA GeoEnvironmental, Boston, Mass.; Sebago Technics, Portland, Me. Sarah Mildred Long Bridge The movable midspan, elevated clearance, and reduced number of piers of this replacement bridge over the Piscataqua River improve marine navigation by Jeffrey S. Folsom, Maine Department of Transportation The new Sarah Mildred Long Bridge between Maine and New Hampshire over the Piscataqua River features twin segmental- concrete approach spans in a stacked configuration leading to a single-deck, hybrid movable span at the bridge's center. Photo: FIGG Engineering Group. 24 | ASPIRE Spring 2019 P R O J E C T

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