Levitated Mass at LACMA


Los Angeles, CA


Los Angeles County Museum of Art


Buro Happold, with Artist Michael Heizer

Construction Manager / Owner's Rep

Aurora Development


2012 | ACI Pankow Award, Innovative Uses of Concrete

In Levitated Mass, Heizer offers a unique and eye-opening experience of walking beneath a boulder that weighs roughly 680,000 pounds and stands over 20 feet tall. Walking down the slot provides a variety of perspectives one is extremely unlikely to encounter in nature, including the eerie sense that the boulder is actually hanging in space. To achieve this feat, the structure had to be strong enough to bear the enormous weight with minimal visible supports, and inconspicuous enough to remain outside the consciousness of the viewer.

Rendering unnoticeable a structure made from over 275,000 pounds of reinforcing steel and 1,400 cubic yards of reinforced concrete required forming continuous walls 456 feet long and up to 18 feet high with tight vertical joints and no horizontal joints at all. The team refrained from using any form ties during pouring and curing, which would have created noticeable scars in the concrete surface. They devised and cast handrails directly into the concrete as a continuous pocket within the walls, concealed drains and achieved very smooth surfaces and symmetrical slopes.

This complex concrete work was accomplished in the unusual site conditions found on LACMA’s grounds in Hancock Park. Construction encountered the area’s high water table, the top of which was shallower than the depth of the trench, and the presence of tar sands and liquid asphalt deposits. Precautions were taken to appropriately manage the unique combination of hazards sometimes found at this site, which can include priceless fossils, combustible methane and highly toxic hydrogen sulfide.

Photo Credit: Michael Heizer