Precast Segmental Highway Viaducts, Hawaii

From the vicinity of Pearl Harbor, the freeway includes the North Halawa Viaducts, the Haiku Tunnels under the mountain range, and the Windward Viaducts on the north slope, where it will connect to the north end of H-3 already in service. The new Windward Viaducts consist of twin parallel prestressed concrete structures approximately 2 km long with 24 spans each. The maximum span length is 91.5 m and column height varies from 3.6 to 48.8 m. The width of each bridge varies from 12.8 to 17.4 m. The geometry of the viaducts includes reverse curves with radius varying between 470 and 753 m and cross slope between 5.5% on one side and 6.8% on the other side. The longitudinal slope of the structure is about 5%. The horizontal distance between the structures is constant on most of length at 21.3 m, but increases at one end where it connects to the two separate tunnels. Crosswise the elevation of the two parallel decks varies by as much as 4.6 m.