Following the demolition of a former Walgreens that closed in 2014, the first major phase of construction is underway at the site of The John Buck Company's 151 North Franklin, a 35-storey office tower at the northeast corner of Franklin and Randolph in Chicago’s West Loop, featuring a design by John Ronan Architects and Adamson Associates. Following the demolition, the site was cleared of debris in February, allowing work to begin on the project's shoring phase.

Shoring at the site of 151 North Franklin, image by Forum contributor harryc

The ongoing shoring work will secure the soil around the perimeter of the site, safely allowing for excavation to proceed without the risk of cave-ins. Owing to the swampy soil conditions found below Chicago's Loop, it is likely that a caisson wall system is being implemented here, rather than the pile and lagging systems typically used for sites with lower water tables.

The process for creating the caisson wall involves inserting hollow steel casings deep into the earth to the bedrock below, then filled them with concrete to create vertical piles. The casings are then removed and the process is repeated around the perimeter of the site. After the completion of shoring work, excavation will commence.

Shoring at the site of 151 North Franklin, image by Forum contributor harryc

The completed development will add 820,000 rentable square feet to Chicago's West Loop, tenants of which will have access to an outdoor sky garden and second floor terrace. The development will also include a conference centre with a 250-person capacity, a café, restaurant, and convenience store. Construction is expected to be completed by the end of 2017.

Rendering of 151 North Franklin, image via John Buck Company

In the meantime, additional images and information about the project can be found in the Database file linked below. Want to get involved in the discussion or share your photos? Check out the associated Forum thread or leave a comment at the bottom of this page.