SoFi Stadium, Inglewood, CA

Construction is finished for the highly anticipated SoFi Stadium in LA. The estimated $5 billion project, located at the former Hollywood Park racetrack, now serves as the home for the LA Rams and LA Chargers and seats over 70,000 NFL fans. To make way for this massive structure, a substantial amount of ground preparation, excavation and improvements were made to the existing site. More than 120,000 cubic yards of lightweight cellular concrete (also known as LCC or foamed concrete) was placed during the construction of SoFi Stadium.

Due to the numerous benefits and versatility that lightweight cellular concrete offers, we placed LCC for different applications on this single job: pipeline abandonment, a quarter-mile trench, canyon retaining wall backfills and pile cap fill.

One of the applications needed was to abandon an existing sewer line. The flowable nature of cellular concrete (also known as foamed concrete) allows it to easily be pumped into a pipeline. One of the risks with abandoning a pipe is the potential of damage to the structure, but with LCC the material can be pumped at lower pressures minimizing the risk of damage to the pipe.

The project’s proposed improvements called for an increase in cover of over 10′ from existing grade elevation. This would exceed the maximum vertical allowable load cover on an existing 87″ RCP pipeline. 1400′ of trench was excavated to be backfilled with Class II cellular concrete over the existing pipe. Class II cellular concrete is about 1/4 the weight of traditional fill and was placed above the RCP pipeline in lieu of the existing fill to reduce/equal the existing vertical load while raising grade to proposed elevation; no additional load is being applied to the existing RCP pipeline after increasing the fill cover depth by over 10′. The pour took place in sections of 100′ (L) x 11′ (W) x 11′ (H) and was completed in one lift; each section took only a few hours to complete.

LCC was placed at the East, West, and North canyon walls of the stadium. Cellular concrete (also referred to as foamed concrete) backfill was required for canyon retaining walls with a design height greater than or equal to 12’. LCC provides a static weight reduction of up to 75%, the result of this significant weight reduction is much lower consolidation settlements and reduced inertial loads and dynamic compression during earthquakes.

To improve seismic performance of the roof structure, columns connected to butterfly caps were placed around the footprint of the stadium. In the design of the stadium, extra measures were taken to support the stadiums roof that is vulnerable to earthquakes. Lightweight cellular concrete (foamed cellular concrete) was poured around the pile caps to allow for movement and serve as a crushable material during seismic activity.