Accounting for Multi-Axial Movement during the Lifting of a Long-Span Roof

The moveable roof sections of Miller Park (the Milwaukee Brewers baseball stadium) exhibit several idiosyncrasies that make them unique in the United States. The triangular moveable panels each span approximately 183 meters (600 feet) over the field, and are approximately 43 meters (140 feet) wide at the outfield end. The panels are supported at three points: a "pivot" point and two "bogies". The pivot bearings are designed to resist forces along, yet allow rotation about, all three principal axes. Hydraulic jacking forces were applied to the different portions of the roof structure during construction and while performing roof repairs in the early spring of both 2003 and 2004. The response of the structure to the jacking is a function of the jacking process. This paper will serve to discuss the different movements anticipated and observed while jacking the roof, and how these movements were accommodated by creative engineering solutions.