Margaret Hunt Hill Bridge in Dallas, Texas by Santiago Calatrava

Article source: Santiago Calatrava

The Margaret Hunt Hill Bridge is a very special project for me. Not only is it a signature component of the City of Dallas’ urban revitalization efforts, but it is also the first vehicular bridge I have built in the United States.

After I was commissioned to design the bridge, I toured Dallas and noticed that the Trinity River basin was littered with industrial buildings, electrical lines and proposed new toll roads. I saw this as a lost opportunity for the City, since the river basin had the potential to be of defining importance to Dallas’ future development. The image below of my initial Master plan model dates to my first involvement with the City’s rejuvenation project in 1999. My concept of linking the City’s two river banks by a series of dramatic bridges and boardwalks across a flooded lakeside environment, sought to revitalize this under-used resource in the heart of the city, and create a recreational facility as important to Dallas as Central Park is to New York City.

Images Courtesy Dana Driensky

• Architect and Engineer: Santiago Calatrava
• Name of Project: Margaret Hunt Hill Bridge
• Location: Located in downtown Dallas, between Continental Avenue and Union Pacific Railroad Bridges the structure will cross the Trinity River Corridor linking West Dallas/North Oak Cliff with the downtown area.
• Client: City of Dallas
• Program: In January 2002 Dallas City Council awarded a design contract to Santiago Calatrava for the creation of a “signature bridge” across the Trinity River.
• Photographer: Dana Driensky

Images Courtesy Dana Driensky

• Start of Construction: 2007
• Inauguration: March 2-4, 2011
• Type of structure: Cable stay steel bridge with pylon
• Materials:
  • Structure of pylon: Steel
  • Structure of deck: Central steel box girder with steel ribs and concrete deck
  • Bents: Reinforced concrete columns on piled foundations
• Dimensions:
  • Length of bridge: 367.6 m (1,206 ft.)
  • Max Span: 183.8 m (603 ft)
  • Width of bridge: 36.7 m (120.5 ft.)
  • Height of pylon: 136 m (446 ft.)
  • Dist. bet. ribs: 6.1 m (20 ft.)
• Steel Tonnage:
  • Pylon: 1,390 metric tons (3,064,000 lbs)
  • Deck: 3,875 metric tons (8,542,200 lbs)
  • Cables: Total = 58 – longest 195.6m (642 ft), shortest 118.9m (390 ft), 31 at 165mm dia. (6.5 in.), 12 at 127mm dia. (5 in.)
• Principal Design: This elegant bridge carries 6 lanes of traffic across the Trinity
• Features:
  • River Corridor:-  The central pylon supports the deck via cable-stays enabling the use of a light, efficient deck system.   The array of cables effectively distributes the forces over the pylon and the symmetry of permanent loads helps maintain a slender, balanced arch pylon.   The arch pylon is a closed steel box with internal diaphragms, stiffeners and anchorages for the cables.
  • The central box girder acts as a spine and contributes greatly to the torsional rigidity of the system which allows the cables to anchor along the centre-line of the bridge.   The regularly-spaced ribs and edge box girders help provide a frame which is stiff in-plane.

Images Courtesy Dana Driensky

The opening of the Margaret Hunt Hill Bridge marks a mighty leap towards realizing this goal. The bridge is an aesthetically stunning structure that serves as a new icon for the city’s skyline. Since the arched pylon rose out of the ground in 2010, the bridge has become a landmark for Dallas. The symbolic nature of the bridge focuses attention onto the river and its environs, and will act to spur further development of the basin. The large clear span bridge will stand center-stage reflected in the man-made lake of the flooded river basin below.

Images Courtesy Dana Driensky

The bridge is a “cable stayed” typology, reinvented by introducing an arched pylon from which cables are dynamically arrayed to support the steel framed highway deck below. The Arch is constructed from precision-engineered steel tube sections stacked one on top of the other and welded in place.

The Margaret Hunt Hill Bridge is the first of a series of bridges designed by my office to span the Trinity River in downtown Dallas, Texas. Work continues on the design of a new sister bridge further along the Basin as part of the scheme for replacement of the Interstate Highway (IH) 30.

Images Courtesy Dana Driensky

Tags: Dallas, Texas

Category: Bridge

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