Effects of Design Provisions on the Response of RC Frame Structures to Foundation Settlements

Differential settlements may occur due to a nearby excavation, consolidation, liquefaction, vibration, or other natural causes. In some cases, buildings are not designed for the conditions imposed by these settlements, which can lead to a structural damage. Certain components of the Canadian design provisions, such as seismicity requirements, could influence the performance of a structure under foundation settlements. Current seismic provisions contain ductility requirements that ensure the development of plastic hinges within the beams, thereby dissipating the seismic energy. Understanding the effects of such provisions on the performance of a building experiencing differential settlement is important in developing comprehensive structural assessments and enhancing current design standards. In this study, the performance of reinforced concrete-framed structures, designed considering different seismic categories, is assessed from strength and serviceability points of view. Three settlement cases are considered, namely prescribed settlement of a center-intermediate column, intermediate column, and edge column. The study provides a critical assessment of the effectiveness of seismic provisions in preventing the loss of structural functionality due to settlement.