Sunday, September 08, 2024

tall buildings, weak, sand/mud foundations

"saved" $6M on installing proper foundation down to bedrock... 

Why Nobody Can Fix This New York Skyscraper - YouTube

161 Maiden Lane - Wikipedia

161 Maiden Lane (also known as One Seaport, 1 Seaport, or Seaport Residences) is an incomplete 670 ft (205 m) tall residential skyscraper on Maiden Lane in the Financial District of ManhattanNew York City,

The building leans 3 inches (76 mm) to the north as a result of the method used to construct its foundation: instead of using the piling method like other neighboring skyscrapers, soil improvement methods were used where chemicals or other material are added to the soil to strengthen it. As of 2024, only half of the finishes, including windows, have been installed.[2]



One Seaport’s site sits upon East River landfill that dates to the turn of the eighteenth century. With rock situated at 132 to 166 feet below grade, initial evaluations of deep foundation systems such as drilled piles and caissons, common to high-rise structures, were performed. The difficulties associated with drilling elements to such depths resulted in extremely high foundation bids from a limited number of contractors. An alternate system, not commonly utilized to support high-rise structures, was proposed. The solution used a jet-grout soil improvement system, to depths of 55 feet below grade, into the sand layer.



another building with same/similar issue:

The Nightmare of San Francisco’s Sinking Tower, Explained - YouTube

Millennium Tower (San Francisco) - Wikipedia


After developers disclosed to authorities in 2015 that the building was sinking and tilting,[26]

the foundation of the main tower consists of a concrete slab built on 60-to-90-foot deep (18 to 27 m) concrete friction piles through the fill and young bay mud

The building is leaning toward the northwest,[30][31][32] and this has caused cracks in the building's basement and the pavement surrounding the tower.[33] As of 2018, the sinking had increased to 18 inches (46 cm) with a lean of 14 inches (36 cm).[34] Measurements in 2022 show the tilt increased to 28 inches (71 cm), as measured from the roof.[35]



A building is only as sound as its foundation.




No comments: