The football expansion in the mid 1990s added a new upper concourse and outer ring of risers increasing seating capacity by more than 21,000 to 80,795. While the “Old Bowl”, the original structure was constructed of cast-in-place concrete, the “New Bowl” was constructed primarily of precast concrete components. For lateral stability, the concourses were designed to act as structural diaphragms, distributing lateral loads from the seating risers to radially and circumferentially oriented precast shear walls. Shortly after construction of the expansion, RRJ investigated areas exhibiting concrete deterioration and structurally evaluated and tested the Old and New bowl structures and components. Repair designs were developed, implemented, and monitored to resolve construction-related issues and provide structural strengthening throughout the complex.
RRJ was retained by the University to investigate concrete distress that had been observed at a number of precast beam/column connections as well as rail post bases. The investigation ultimately included:
- Structural evaluation of the New Bowl
Review and analysis of the New Bowl’s overall and component structural designs; a visual examination of all primary structural members and connections; a crack and delamination survey of all topping slabs; and core sampling of topping slab areas to check thickness, bond, and reinforcement location.
- Examination of all grout-embedded rail posts
Documentation of distress conditions such as rust stains, failed sealants, and concrete cracking and spalling; a review of project plans and specifications and railing material and shop drawing submittals; and laboratory testing of field-retrieved grout samples and comparison with samples made from new
- An evaluation of the Old Bowl concrete structure
Review of the original Old Bowl structural plans; an examination of all portions of the cast-in-place concrete support structure and seating risers; a sounding delamination survey of the seating riser top surfaces; sampling and laboratory testing of existing concrete and patching materials; and monitoring concrete moisture levels at various locations within the seating area.
