Dive Brief:

• On land reclaimed from San Francisco Bay early in the 20th century, construction crews are sinking piers to bedrock so an 800-foot-tall residential and commercial tower can rise above, and they are doing it one at a time.
• The site, known as 181 Fremont, is 140 feet square, and just storing materials for one shaft at a time and assembling rebar baskets is a challenge, with the piers averaging 255 feet and going into the ground at a rate of one every three days.
• The 55-story tower that will rest on the piers will have a steel megaframe exoskeleton through the 36th floor and a braced-frame core the rest of the way to handle both seismic and wind stresses.

Dive Insight:

Arup is the structural engineer for the project, which is scheduled to be done in mid-2016. The design, which is being peer reviewed, aims to reduce vibration for people who will be living on the uppermost 17 floors. It will be the second-tallest building in the City by the Bay until the 1,070-foot Transbay Tower eclipses it.