Lakefront bicycle trail 3 - the navy pier flyover

Aldridge was contracted by the City of Chicago to provide updated infrastructure for the new lakefront trail known as The Navy Pier Flyover. The Chicago Lakefront Trail is an 18.5-mile shared-use path for walking, jogging, skateboarding, and cycling, located along the western shore of Lake Michigan. The trail passes through and connects four major lakefront parks along with various beaches and recreational amenities. It also serves as a route for bicycles, skateboards, and personal transporter commuters. On busy summer days, 70,000 people use the trail.

The current and final phase of the project consists of building a new bike path over the Chicago River onto the east side of the existing Lake Shore Drive Bridge. The bike path is being built to go through both the northeast and southeast bridge towers. Due to the bike path being installed through levels of the bridge that contain the electrical components that power the bridge to allow it to operate, the bridge towers are receiving full electrical upgrades to the DC operating control system. During construction, Aldridge was responsible for operating the bridge weekly during the spring and fall boat seasons.

Aldridge digitally scanned the entire project and built all of the electrical conduits into a BIM Model to facilitate the building of all of the conduits in our prefabrication shop prior to site delivery. Some major scopes of the project include the installation of five submarine cables across the river between the bridge houses, a new DC Electric Control System, new traffic signals and gates, and lighting upgrades along the lakefront bicycle trail.

As a separate contract, Aldridge is working to complete the Lakefront (bicycle) Trail, with the final phase requiring a new bridge connecting to Lake Shore Drive over the Chicago River. The bridge support will come from an extension of the existing boathouses on either side of Lake Shore Drive. Aldridge’s scope includes drilling micro piles to support the new foundations of the buildings. Each bridge house has seven new foundations, and there is a single micropile to support the column just South of the river.

In order to provide protection from marine traffic colliding into the boathouses, Aldridge is driving a cluster of pipe piles at each location to create what is called a dolphin.  Each dolphin consists of 37 steel pipe piles 14 IN in diameter, driven 40 FT into the riverbed.  The cluster of piles will be filled with stone and concrete and topped with a steel shield plate that will give it a unique hexagonal look.  The dolphin extends 7' above water level.

A unique aspect of this project is that the work is being performed from a floating barge. The micropile scope requires a drill rig and support crane operating on the barge at the same time. The dolphin scope requires the crane supporting leads and a hammer to drive the pipe piles while on the barge. The crew was trained extensively in order to safely perform this work. Additional engineering was done for each equipment and material configuration to understand the storage limits in order to avoid the barge lifting while performing each operation.

This project was featured in Construction Tech Review Magazine, you can view the article here.