As part of a joint venture, Traylor Bros., Inc. is constructing the Honolulu Authority for Rapid Transportation’s (HART) Airport Guideway and Stations Design-Build Contract. The approximately $875 million contract is to design and build the project. The new 5.2-mile elevated guideway will extend from Aloha Stadium to the Middle Street Transit Center Station in Honolulu, Hawaii and includes four stations. This is the third in a series of projects to design and build the Honolulu Rail Transit Project, a 20-mile grade separated fixed guideway transit system with 21 stations.
The job required casting 2,703 segments at an off-site precast yard and transporting them 5 to 10 miles to the urban job sites. The segments are more than 30 feet wide and weigh between 45 and 65 tons. When production was at its peak, the yard produced 36 segments each week. The larger pier segments were produced at the rate of one per weekend, with six typical segments and one pier segment each weekday. In addition to casting more than 2,700 segments, the yard also produced the 5,400 permanent sound walls that will be placed along the entire alignment.
The project team made deep foundation construction history in June 2020 when they successfully installed the largest diameter and deepest single-cased caisson in the world. The rail column drilled shaft caisson was 10 feet in diameter with a casing length of 357 feet to a bottom of pile elevation of negative 332 feet.
A few challenges arose when developing the track plinths, primarily with the concrete. While testing mix resistance, it was found that locally sourced aggregates have a high porosity, acting like a freeway to pass an electrical charge. Through continued research and development with the local suppliers, the team was able to meet the lower mix resistance to an acceptable value.