Editing Big Dig (section)

=== Engineering methods and details ===
[[File:BigDigSupportsCentralArtery.agr.jpg|thumb|Temporary supports hold up the elevated Central Artery during construction.]]
Several unusual engineering challenges arose during the project, requiring unusual solutions and methods to address them. At the beginning of the project, engineers had to figure out the safest way to build the tunnel without endangering the existing elevated highway above. Eventually, they created horizontal braces as wide as the tunnel, then cut away the elevated highway's struts, and lowered it onto the new braces.<ref name="AP 122507">{{Cite news |url=https://news.yahoo.com/s/ap/20071225/ap_on_re_us/big_dig_the_end |archive-url=https://web.archive.org/web/20071228035119/http://news.yahoo.com/s/ap/20071225/ap_on_re_us/big_dig_the_end |archive-date=December 28, 2007 |title=Boston's $14.8B Big Dig finally complete |first=Steve |last=LeBlanc |agency=[[Associated Press]] |date=December 25, 2007}}</ref>

Three alternative construction methods were studied with their corresponding structural design to address existing conditions, safety measures, and constructability. In addition to codified loads, construction loads were computed to support final design and field execution.<ref>{{citation |author=Chalhoub Michel Soto |title=Construction Method and Supporting Structural Design for the Boston Area Central Artery Project |date=Aug 1999 |publisher=report#005081999 Integrated Services-CEM Eng Lib}}</ref>