When motorists take to San Francisco’s new $1-billion Presidio Parkway in late 2013, they won’t see some of the massive foundation piles placed deep into ground below. But they will feel the support of some of the largest cast-in-drilled-hole piles currently in use.
“The biggest challenge on this job from the beginning was a requirement to use 12-ft-diameter piles and [insert them with] very limited vibration because of historic buildings in the Presidio,” says Peter Faust, project manager for San Francisco-based Malcolm Drilling Co. “This meant we couldn’t use a pile driver with an impact hammer.”