Wrigley Field – The 1060 Project-Paper

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The 1060 Project was a privately funded, $750 million renovation and expansion of Chicago’s historic Wrigley Field, begun after the 2014 baseball season and planned for completion before the 2020 season. Work included stadium upgrades, replacement bleachers, a new underground clubhouse beneath an open-air plaza, and an adjacent office-retail tower and hotel. Construction had to fit within off-season windows of no more than 23 weeks while preserving baseball, concerts, seating capacity, and the fan experience.<br /><br />The site’s challenging subsurface conditions included shallow groundwater, beach sands and silts, soft lakebed clays, and deeper, stiff glacial deposits known as Chicago hardpan. Investigation included 54 borings, in-situ testing, rock coring, and groundwater monitoring.<br /><br />The century-old stadium had irregular framing, incomplete as-built records, and foundations bearing in sand. To support increased and temporary construction loads, engineers underpinned 27 major F-line columns and 48 additional locations using rock-socketed micropiles installed with low-clearance equipment. A staged jacking and load-transfer process connected the existing columns to the new supports.<br /><br />The deteriorated bleachers were replaced with a steel-frame structure on belled caissons. Pressuremeter testing enabled higher allowable bearing pressures than standard code values, making enlarged-base foundations economical. For the office tower’s deep basements, top-down construction and secant pile walls helped limit ground movement; the shallower clubhouse excavation used sheet piles with tiebacks, berms, and rakers.<br /><br />Finite-element analyses modeled staged excavation and time-dependent soil and structural behavior. Monitoring systems tracked movements in real time, with alarms set at specified thresholds. Wall deflections and stadium movements generally remained within design limits, though two locations reached the allowable movement limit.<br /><br />The project’s success depended on close coordination among designers and contractors to deliver technically complex work within tight seasonal schedules while preserving Wrigley Field’s historic character.
Keywords
Wrigley Field
1060 Project
Chicago stadium renovation
micropiles
secant pile walls
belled caissons
top-down construction
geotechnical engineering
underpinning
historic preservation