161 Maiden Lane has quite a tumultuous past. What was supposed to be luxury high-rise living in the Financial District of NYC, with a sweet view of the East River, turned into a financial fiasco and a construction blame game that put a halt to the potentially unfixable leaning tower that has been described as "banana-shaped."
In 2015 Fortis Property Group broke ground on One Seaport, which was supposed to be a US$272 million, 60-floor, glass-encased, luxury river-view project. Fortis expected to sell the 80 units for anywhere from $1.2 million to over $18 million for its penthouse listings.
When construction commenced, Fortis opted to take the easier, cheaper route of making a foundation for the 670-ft-tall (204-m) building to sit on, as it would save the company around 2.21% of the overall construction costs. And that's where this legend begins.
Skyscrapers in New York City's financial district generally use pile foundations. Construction starts by drilling steel pylons into the bedrock below ground – typically around 50 ft (15 m) deep in that area – before starting the above-ground floors. It has been this way since the late 1800s. Unfortunately for Fortis, its $64 million site was located on what is known as Colonial "infill." In the 1600s, the Dutch laid out Maiden Lane with whatever infill they could get their hands on: rocks, sand, trash – anything they could find to expand the footprint of the island for more real estate.
Fortis had hired geotechnical surveyors who found a 24-foot (7-m) layer of infill composed of everything from gravel and bricks to old docks and shipwrecks. Below that, a layer of former marshland, then sandy glacial deposits from thousands of years ago, some decomposed rocks ... and finally, about 155 ft (47 m) below the surface was bedrock, the stuff skyscrapers are ideally built on.
Instead of digging down 14 stories to install a pile foundation for this incredibly tall and skinny structure – 15:1, if you can believe it – Fortis elected to inject concrete into the soil to firm it up. "Soil improvement," the company called it, and it would shave $6 million off the top; a savings of 2.21%. An engineering consultant submitted a nearly 100-page report listing all the reasons why that would be a bad idea, citing reasons like "differential settlements," i.e., "it might lean." The report went unheeded, and construction commenced.
For more history on 161 Maiden Lane check out this article:
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