A new perspective on the effects of abrupt column removal

This manuscript presents the development of a perspective for the analysis and design of floor systems to survive abrupt and complete removal of a column. The subject is treated under the premise that an event leading to an abrupt column removal is, inherently, extremely difficult to foresee and quantify a priori. It is, therefore, suggested that the proposed design method for column removal is useful as a vehicle to ensure redundancy of a floor system but not as a predictive tool. In such context, this simple method should be preferable over a complex approach. It is proposed that, a floor system can be designed to survive the sudden removal of one of its supports by:(1) Proportioning the system by using the results from a conventional linear static analysis of a model that excludes the column to be removed and a load factor exceeding 1.5;(2) Providing adequate detailing to ensure that the system can reach deformations exceeding 1.5 times the deformation associated with the development of its full strength (“yield deformation”).Through seven examples this manuscript shows that the proposed formulation provides estimates that agree with results obtained from nonlinear dynamic analyses.