In the balanced-cantilevered construction of the Bridge Project, there are 10 50‑foot‑long roadway segments of the main span that extend in both directions from each tower, ultimately connecting with their respective approach structures and over the channel. Around the start of construction of the 6th segment, crews installed giant rust‑colored stabilizer columns at the halfway mark at both towers to keep the cable-supported main span from “weather-vaning” during high winds or swaying during a seismic event.
The story of the stabilizer columns represents an innovative approach to sustainability and reuse on the project. The 8-foot-in-diameter hollow steel columns were first used as shafts for drilling many of the more than 350 piles that support the 100-plus approach columns and two towers. As each shaft was filled with rebar and concrete that cured, these long encasings were shimmied back to ground level, leaving the deep pile underground.
When the construction team needed to install the stabilizer columns, pile construction was largely finished. Rather than scrapping the encasing shafts, crews repurposed them, saving the project a great deal of money.
Next week, crews will begin disassembling the stabilizer columns as the main span is now connected to the approach structures, and the threat of weather-vaning or seismic swaying is gone. The columns will be removed on the west tower segments of the main span first, followed by the ones on the east tower. In the photo above, you can see the columns at the east tower before they come down.