The new Levi’s Stadium in Santa Clara opened for the 2014 NFL season after a very aggressive construction schedule beginning in 2012. This enormous project had a very demanding schedule that required engineers and contractors to employ many methods to speed construction to open for the 2014 season. Which it did successfully… six weeks early.
The open air football stadium includes thousands of stepped/pre-cast concrete panels that serve as the foundation for the fan seating areas. These pre-cast structures are steel reinforced and were manufactured off site to reduce the forming cost/time on site and increase consistency of the ‘skin on the bones’ of the steel structure. The stair stepped panels were installed in late 2012 after a record breaking steel erection timeframe of the super structure. As part of the overall seating and viewing area plan, hundreds of flat platforms were included in the design to accommodate ADA ramps, wheelchairs, TV cameras and various other uses. Engineers with HNTB, one of the world’s foremost firms specified the use of Expanded Polystyrene (EPS) Geofoam to constitute the structural void fill to support the ramps and platforms. EPS Geofoam was used due to its’ extreme low density and high bearing capacity to support the concrete topping slabs. By using an ultra-lightweight soil replacing fill material, EPS Geofoam significantly reduced dead and lateral loads on the pre-cast panels by adding elevation and slope without a lot of weight.
Conco Company of Concord, CA worked as a sub-contractor to Turner– Devcon Construction, the prime contractors furnished and installed the Geofoam as part of their large concrete package. Conco workers installed 3,500 cubic feet of EPS39 and 25,000 cubic feet of EPS15 for various ramps and platforms throughout the new stadium. The lightweight fill was provided by the local Insulfoam facility in Dixon, CA along with electrical hot wire tool kits which allowed workers to cleanly and easily fabricate the blocks on the jobsite.
The single largest benefit to concrete contractors when using Geofoam is the ability of the material to constitute half of the form and the fill simultaneously which completely eliminates the concept of a two pour operation.
EPS geofoam is approximately 1% the weight of soil and less than 10% the weight of other lightweight fill alternatives. As a lightweight fill, EPS geofoam reduces the loads imposed on adjacent and underlying soils and structures. Utilizing EPS geofoam benefits construction schedules and lowers the overall cost of construction due to its ease of handling during construction…. often without the need for special equipment, and is unaffected by occurring weather conditions. EPS geofoam can be easily cut and shaped on a project site, which further reduces jobsite challenges.
Levi’s Stadium Project Team
Engineer/Architect: HITB Corporation
Concrete Contractor: Conco Company