Situation
As West Oahu continues to develop, so does the need for more housing and amenities. The Ho‘opili master-planned community includes seven community and recreation centers, more than 200 acres of commercial farms and community gardens, and three million square feet of shopping and dining options. Additionally, Kohina and Ho’opili is West Oahu’s very first transit-oriented development. Cultivating a community that revolves around the future rail system is not only a new concept to Hawaii but especially West Oahu. Kohina has approximately 276 multi-family homes and commercial spaces.
Solution
The project began with the mass excavation of 110,000 CY of material from a retention basin expansion including a scraper haul that was more than two miles long, completed over the course of three months with the help of Cat 627 scrapers. Field crews were tasked with keeping the haul routes secure during long shifts so scrapers could make the long haul without any issues. The scrapers were also used to “box out” some of the deeper and wider trenches for the sewer line, as well as a large reinforced concrete drain pipe. In addition to accelerating an aggressive utility schedule, this also provided the fill material needed to complete the project’s mass grading. The utility and grading work required constant coordination with several farmers, other heavy-civil contractors, and several inspectors assigned to monitor the project. Despite these challenges, our earthwork crews completed the site mass grading and our utility crews installed 4,933 LF of sewer lines, 8,464 LF of waterlines, and 7,553 LF of drain lines.
Notable
A unique feature of the project is its connection to Kualakai Parkway which involved a quadruple box culvert with utilities and concrete paving installed above it. This 100-foot-long by 66-foot-wide cast-in-place quadruple barrel box culvert is the foundation for the main roadway into Ho‘opili Phase 2 and Parcels 20 and 25. In addition, the main water source for the Ho‘opili development is within the roadway, and GBI had to expedite all work tied to the waterline.
Crews worked 12-plus hour shifts seven days a week to finish the box culvert and waterline. In addition to the challenge of having crews work through the rainy season at the invert of the areas’ main drainage channel, the box culvert and roadway also run directly through the rail station construction site. GBI managed to expedite the construction of the box culvert and the majority of the adjacent wing walls, all while sharing access with the rail station’s main crane on the jobsite.
