The four-year project involved transporting a 21-foot-diameter, 340-ton boulder from a Riverside quarry to LACMA, where it spans a 456-foot-long subterranean pedestrian ramp next to the La Brea Tar Pits. Victor Langhaar was the Lead Geotechnical Engineer from project design through construction. Completed in 2012, Levitated Mass drew national attention and was the subject of a documentary feature film focusing on the boulder’s 11-day trip to LACMA.
The project faced several unique and interesting geotechnical engineering challenges. Characterizing the rock mass and intact properties of the boulder were central to engineering the transport and “levitation”. Due to the project’s artistic nature, the design of the supporting slot structure required an unusually low tolerance for settlement or deflection. Also, several temporary excavation and gantry crane options were necessary for the final setting of the boulder due to transport variables and logistics.