The Leonard P. Zakim Bunker Hill Memorial Bridge in Boston connects the underground city highway with Interstate 93 and U.S. Highway 1 The building was built as part of the Big Dig major urban development project in the years 1997 to 2002. The bridge spans a total of ten lanes of the Charles River and is 56 m, the widest cable-stayed bridge in the world. The structural system of the striking due to building a new cable guide was created with the advice of the Swiss Professor Christian Menn. The bridge is named after the Boston civil rights activist Leonard P. Zakim and the Battle of Bunker Hill.
The main bridge has five openings with spans of 39.6 m and 34.1 m in the southern side panels, 227 m from the main field and 76.2 m and 51.8 m in the northern side openings. The length between the joints on both sides is 430 m.
The pylons of the cable-stayed bridge zweihüftigen have a λ-shape and are arranged concentrically about the eight lanes of the I 93rd Two additional side lane of a ramp located on one side, east next to the pylons which are Total 98.4 meters high and made of reinforced concrete.
The bridge has an unusual rope guide in the fan system. Due to the eccentric arrangement comprises two lanes cable layers are present in the primary port, which are anchored at the edge of the bridge girder in a wire spacing of 6.0 m. In contrast, only one anchored in the middle rope bridge support level is present in the two marginal fields. In addition, the ropes are anchored not only in the vertical pylon top, but also in the oblique pylon supports.
The track beam is perpendicularly arranged in the main field as a light construction with steel ropes to anchor the longitudinal members and to form 3.0 meter high steel cross-members at a distance of 6.0 m. The deck is made of reinforced concrete. However, the side panels have a heavy reinforced concrete superstructure.