Constructed in 1924, Michie Stadium in West Point, New York -- the football stadium for the United States Military Academy -- is one of the most beloved structures of its kind. At the dawn of the new millennium, many construction projects were undertaken to meet the new demands on this old structure. These included renovations, a new athletic center and press box, the Hall of Army Sports, the 150,000-square-foot addition of a new strength and development center, an auditorium, and other amenities. These new structures were to be constructed outside and immediately adjacent to the existing stands. During the excavations for the new facilities, however, it was discovered that the footings of the columns and bearing walls of the stands were bearing on soils above the proposed bottom of excavation. This scenario caused great concern about the potential instability of the stadium structure. Underpinning of the footings was deemed the only option; however, there was also concern about significant impact to the construction schedule.

Working in concert with Schnabel Engineering, Structural Preservation Systems' GeoStructural Division provided a turnkey solution to this problem that included utilization of micropiles for underpinning the footings prior to the start of the excavations. The micropiles were conceived as self-drilling, self-grouting bars embedded five feet into the rock. For the column footings, Schnabel Engineering designed a reinforced concrete cap attached to the existing pedestal. The bars were provided with a top plate that was embedded in the pile cap concrete. Then, for the wall footing, a bracket was used to transfer the load from the wall to eccentric micropiles. This efficient design facilitated an accelerated micropile installation time with reduced or no impact to the project schedule. In fact, the entire underpinning system was in place in a mere week.