Alternative Load Path Analysis of a Prototype Reinforced Concrete Frame Building: Fid-Bau Portal

Alternative Load Path Analysis of a Prototype Reinforced Concrete Frame Building

Bao, Yihai / Main, Joseph A. / Lew, H. S.

This paper presents alternative load path analysis of a 5-bay by 5-bay, 10-story prototype reinforced concrete moment frame building under column loss scenarios. This prototype building is used for example analysis problems in the Alternative Load Path Analysis Guidelines, which are being developed by the Disproportionate Collapse Technical Committee of the Structural Engineering Institute, and the analyses presented in this paper have been submitted for inclusion in these guidelines as part of the chapter on advanced numerical modeling. The prototype building was designed for seismic design category C, for a location in Atlanta, GA. Intermediate moment frames were selected as the lateral force-resisting system and were designed in accordance with the requirements of the American Concrete Institute 318 Building Code. A two-way concrete slab was used at each floor level, including the roof. Using a reduced-order finite-element modeling approach, full-building analyses are presented under three different first-story column loss scenarios, including a corner column, an edge column, and an interior column. Results from nonlinear dynamic analysis (i.e., sudden column removal) are compared with results from nonlinear static analysis (i.e., push-down analysis) using an energy-based procedure to account for the dynamic effects of sudden column loss. The robustness index for the building is also evaluated based on its ultimate capacity under the same set of sudden column loss scenarios.