Steel Moment Frame Connection Performance Limits for Disproportionate Collapse

Disproportionate collapse is an extreme loading event requiring consideration of all available load paths within a structure. Current criteria quantify acceptable performance limits through the use of seismic documentation. For steel moment frame structures, specifically, ASCE Standard 41-06 is used to quantify a loss of moment resisting capacity in the beam-column connections. This currently serves as the performance limit for the disproportionate collapse analysis of steel moment frame structures. A case study is presented featuring the disproportionate collapse analysis of an existing 33-story steel moment frame building using the nonlinear dynamic finite element program, LS-DYNA. The limitations encountered using ASCE 41-06 performance limits for disproportionate collapse analysis are discussed and finite element modeling considerations are enumerated. Furthermore, recent research on the collapse performance of seismic steel moment frame connections supporting this case study's conclusions regarding the limitations of ASCE 41-06 for disproportionate collapse analysis is discussed and recommendations for further research are proposed.