The bridge is being built from the riverbed up. More than 1,000 steel piles were driven deep under the riverbed to form a base. Ideally, these cement-filled pipes should sit on bedrock. But in some areas, that solid layer of underground rock was too deep to reach. In such areas, the piles are supported by friction. The clay, silt, and other sediment under the riverbed rub against the surface of each pile. The resulting resistant force is strong enough to steady the piles so they can support much of the bridge’s weight.
Once the piles were in place, barges carried pre-made 122 meter (400 foot)-long steel sections of the two roadways from a construction site upriver. A floating “supercrane” lifts the sections into place. When construction finishes in 2018, the piles and cables will support two roadways with four general-use lanes each, emergency access, and room for future mass transit.