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/532296
PROJECT Honolulu Rail Transit Project (Segments 1 and 2) Improving the quality of life in a highly congested urban area By Jose Rodriquez, FIGG The Honolulu Rail Transit Project is a 20-mile elevated rail line on the island of O’ahu that will connect west O’ahu with Down town Honolulu and the Ala Moana Center via the Honolulu International Airport. The system features state-of the-art, electric, steel-wheel trains that will travel the entire route through 21 stations in 42 minutes. Trains will travel on steel rails and will be powered by a third rail. The $5.16 billion project will provide approximately 10,000 direct and indirect jobs per year. Honolulu Authority for Rapid Transportation (HART) developed the project to improve mobility, enhance reliability, and address the island’s increasing congestion. By 2030, the rail system will handle approximately 120,000 trips per weekday, reducing roadway traffic by about 40,000 vehicles. This will reduce overall commuting times and costs and enhance the quality of life for the residents of O’ahu. The western-most 10 miles of the project’s guideway system are being completed through two design-build contracts. Project Alignment O’ahu’s mountainous landscape and congested roadway system in this project segment make it difficult to build a new guideway. The project requires erection of the guideway on the shoulder or in the limited-width median of the existing 2- or 3-lane roadway for 7.5 miles. The route includes intersecting roads and left-turn pocket lanes in the median. The guideway alignment consists of various straight and curved sections with a minimum radius of 1100 ft for precast concrete sections and 800 ft for cast-in-place concrete sections. The maximum vertical profile grade is 5.5%. The contractor is using a plinth less design for the rail support, connecting the rails directly to the top of the guideway deck with fasteners and requiring super elevation in curved alignments. Structural Solutions To solve the challenges of material delivery, mobility, and erection of the structure that are posed by the project’s congested, urban location, the guideway was designed to be built from above using precast concrete box girder segments. The contractor is precasting the segments at a site approximately 5 miles away while also building the substructure elements on site. The project consists of 438 total spans, 430 of which are made of precast concrete and range in length from 68 to 151 ft. The remaining eight are made of cast-in-place concrete with span lengths ranging from 204 to 342 ft. PROFILE HONOLULU RAIL TRANSIT PROJECT / HONOLULU, HAWAII BRIDGE DESIGN ENGINEERS: Segmental Superstructure: FIGG Bridge Engineers, Tallahassee, Fla., and Substructure: HNTB, Lake Mary, Fla. PRIME CONTRACTOR: Kiewit Infrastructure West Co., Vancouver, Wash. POST-TENSIONING SUPPLIER: Schwager Davis Co., San Jose, Calif. OTHER MATERIAL SUPPLIERS: Formwork: EFCO Corp., Des Moines, Iowa, and Bearings: D.S. Brown Company, North Baltimore, Ohio PRECASTER: Kiewit Infrastructure West Co., Vancouver, Wash. CONSTRUCTION DRAWING PREPARATION: FIGG Bridge Engineers, Tallahassee, Fla.