Abstract:
There is a lot to be excited about in Tiger Town if you’re a fan of Detroit’s Major Leage Baseball Team. While fans were cheering along as the team celebrated their first playoff appearance since 2014, the team at Comerica Park was planning a major upgrade to the fan experience. The Comerica Park Home Plate Club, a new premium seating option for Tigers fans, consists of semi-private loge boxes right behind home plate along with direct access to the new exclusive high-end dining and bar options.
To facilitate access to the new club level, two elevators were designed to accommodate both freight and guests. Located inside the existing ball park, a permanent earth retention system (ERS) was required to not undermine the existing foundations and other ballpack facilities that would remain in place. Nicholson Construction Company was contracted by Construction Manager Barton Malow Builders to construct the ERS.
A micropile and lagging wall with one row of tiebacks was constructed to make way for the two new elevator shafts. Nicholson’s scope also included waterproofing and a permanent shotcrete face. While the 1,500 sqft of shoring appears small in quantity, the project required creative thinking, close coordination, and attention to detail to deliver the schedule-critical scope on time.Â
The major challenge for the ERS construction was dealing with the limited access and headroom working inside the existing stadium. Extensive demolition and earthwork were required to provide access to get a drill rig up into the existing basement level, and even then, headroom was limited to as low as 12 feet for micropile construction. Micropiles were typically 40 feet long and were drilled with duplex drilling method to protect the existing structures and limit the mess being made inside the small work area. Bar tieback anchors were drilled to a length of 35 feet and were post-grouted. Unique details were required for the lagging connection and walers to not protrude past the outside face of the micropile casing necessitating meticulous welding work. Once the excavation progressed to the bottom of the shaft, a temporary scaffolding system was constructed to provide access for the permanent wall construction which was shot in using gunnite.
Despite the formidable physical obstacles standing in the way of the ERS construction, time was another major factor. The original construction season was limited between the end of 2024 season on September 29th 2024 and the always heavily anticipated Opening Day date of April 4th 2025. However, the team’s unlikely playoff run in 2024 pushed back the project start about two weeks. With the fixed 2025 Opening Day, Nicholson worked an accelerated schedule to keep the elevator work on track.
This presentation will dive into the measures taken to overcome access and headroom limitations, construction methods used to install the micropiles, tiebacks, and lagging, and discussion on close coordination used between the stakeholders to react to unforeseen challenges along the way.