A few of the first H-piles at 1326 South Michigan.

If you’re out searching for caisson work, don’t waste your time at 1326 South Michigan. The 46-story, 500-unit tower from Murphy Development Group and CIM Group won’t have them. Instead, the SCB-designed tower will sit atop H-piles, which Stalworth Underground is on site attending to now. According to Stalworth, the South Loop soil simply isn’t made for caisson work, so H-piles will be driven about 90 feet down into the bedrock.

How many H-piles does it take to support a 47-story building? 360, again according to the folks at Stalworth. Each pile is capable of supporting 350 tons, so that’s 252 million pounds of concrete and steel and glass and sofas and appliances that can be supported. Oh, and 190 cars. That’s a decent amount of weight there, too.

Stalworth started driving piles at 1326 South Michigan last week.