The US Army Corps of Engineers operates the Chicago Harbor Lock, located at North Pier, adjacent to Navy Pier. This lock separates Lake Michigan from the Chicago River and is one of two entrances to the Illinois Waterway System. It is the fourth busiest lock in the nation for commercial use and second busiest for recreational use. This $7 million reconstruction project widens the pier and provides stability to the lock, which was originally constructed in the 1930s.
Project Fast Facts
Owner: US Army Corps of Engineers
Location: Chicago, IL
Work Performed: Drove 600 SF of new sheet pile, 50-ft deep, and tie-rods anchored across 70 ft to an existing whaler and sheet pile wall system. 28,476 SF of new sheet pile wall; 100, 70-ft anchored tie rods; 600 LF of C 12X25 Whaler; 14,600 CY of Clear Drive Line; 1,200 CY of Structural Concrete
Project Scheduled: 1 year and 4 months
Completion Date: Anticipated completion in September 2021
The Work
The original North Pier sheet pile wall on the river side was supported by tie rods that were corroding and tied to a failing tunnel structure. Superior Construction was hired by Integrated Environmental Services to complete the project. In the first phase, we stabilized the crib structure. The team used a specialized excavator equipped with a modified dipper arm on a sectional barge to clear the drive line in front of the existing sheet pile wall and make way for the new sheet pile wall. Crews drove 600 SF of new sheet pile, 50-ft deep into Lake Michigan. We then connected a whaler from the top of the new sheets to the existing riverside sheet pile and anchored it with new 70 ft long tie rods.
For phase two, Superior is demolishing the existing utility tunnel — originally built in 1938 and with limited load capacity — in order to pour a new promenade concrete slab on top. We will also widen the pier from 35 to 70 ft.
The Result
In summer of 2020, Lake Michigan experienced record-high water levels. Because of experience with marine work and Lake Michigan specifically, the team was able to complete phase one, even though it meant working two feet underwater. Superior also successfully navigated the challenge of working with the restricted tunnel load. The success of the project protects the safety and stability of the lock, which prevents Lake Michigan from flooding the Chicago River. In addition, because of the widened pier and increased load capacity, lock workers and emergency personnel will be able to drive out to the lock in the event of an emergency. The overall work on the pier and lock helps to clean up and beautify the prominent Navy Pier area of the Chicago skyline.