The 18.5-hour construction of the 13,478-cu-yd mat for the $1-billion Grand mixed-use development in Los Angeles ranks as the second largest continuous casting of a foundation in Los Angeles, after the Wilshire Grand’s, which, at 19.5 hours, set a Guinness World Record in 2014.
At 9:30 p.m. on Friday, June 28, at a rate of approximately 1,000 cu yds per hour, 140 workers from the Conco Cos. began the job, which required 1,348 truck trips to six batch plants, for the mat, which contains 13,478 cu yd of concrete. The mat will support a 39-story tower.
“Due to precise and complicated logistics, the mat’s coordination started four months prior to the actual pour,” says Barry Widen, vice president of design and construction for developer Related Cos.
The mat is 39,303 sq ft with a thickness that varies from 6 ft to 12 ft. The concrete truck fleet traveled eight times between the site and six batch plants. With seven of eight concrete truck pumps staged on streets, Related coordinated with Los Angeles City Council District 14, and the city’s Dept. of Transportation and Bureau of Engineering’s Major Transit and Transportation Construction Traffic Management Committee (TCTMC) to minimize the impact to traffic, which required complete closures of Olive Street and 2nd Street and directional closures on Grand Avenue and 1st Street.
In February, Related and partner CORE USA broke ground on the project, designed by Gehry Partners and located across the street from Gehry’s Disney Concert Hall. The project is expected to create 10,000 new jobs and $1.3 billion in one-time total economic output for Los Angeles County. The Grand will include 176,000 sq feet of retail and a hotel in 20-story second tower. Related expects the second mat will be cast this month.
AECOM is the Grand’s construction manager and DCI Engineers is the project’s structural engineer.
Editor's Note: This story has been updated to clarify that there were 1,348 truck trips required for this concrete placement. The project team has not specified the number of trucks utilized.