Permanent Earth Retention at Comerica Park-PPT Presentation

PPT Presentation

Pdf Summary

The Comerica Park premium-section renovation required a permanent earth-retention system to support new climate-controlled seating, a bar and lounge, and elevator access. Work took place in a tight, low-headroom area, so the team arranged for demolition before mobilization and planned access through a freight elevator or truck ramp. Lessons from an earlier stadium project—including groundwater concerns—prompted additional hand probing and contingency planning.<br /><br />The baseball season delayed the start of construction, pushing mobilization from October 14 to October 24. To recover time, the crew worked night shifts.<br /><br />The retention system included 16 micropile soldier piles totaling 610 feet. Limited headroom required specialized equipment with a detachable power pack and removable mast extension. Drilling water was recirculated from the field, and the piles were grouted using tremie and pressure-grouting methods. Grout consumption averaged 144% of theoretical volume, with an artesian condition encountered at the first pile.<br /><br />Tieback drilling plans changed after sand backfill was discovered near the stadium’s “C line.” Four of the 15 anchors were drilled using temporary casing and water. All tiebacks were post-grouted, tested, and locked off at 100% of design load; performance and extended-creep tests were also conducted. The largest movements occurred in sandy areas.<br /><br />Lagging and walers required extensive field welding, coordinated closely with excavation sequencing. Waterproofing and the final gunite facing were subcontracted, as was automated monitoring of the existing structure and soldier-pile movements.<br /><br />Night work saved two schedule days during micropile installation and three during tieback work, helping the team manage the compressed schedule.

Keywords

Comerica Park

earth-retention system

micropile soldier piles

tieback anchors

limited headroom

groundwater concerns

tremie grouting

night shifts

gunite facing

automated monitoring