Seismic Performance Study on Rc Wall Buildings From Pushover Analysis

Abstract

Buildings built completely with RC walls without frame elements are fast gaining popularity especially in urban areas. Advance in formwork technologies have made RC wall buildings an obvious choice for mass constructions because of their economy and speed of construction. Seismic performance of RC walled buildings is of primary concern in the analysis and design of such structures. Modeling of RC walls using layered shell elements has made it possible to accurately model the reinforcement configurations in RC walls and to capture the nonlinear behavior of walls efficiently. With the help of suitable nonlinear material models for concrete and reinforcing steel, pushover analysis can be conveniently adopted to assess the seismic performance RC walled buildings. In the present study, RC walls are modeled and analyzed using SAP 2000's pushover analysis capability on layered shell elements. Various parameters such as aspect ratio of walls, reinforcement detailing aspects and presence of openings are chosen to study the seismic performance of RC walled buildings. Results of analysis have revealed that incorporation of ductile detailing in the form of boundary element significantly improves the seismic performance of RC walls specially the displacement ductility of the wall and the effects are more pronounced when the bottom storeys are strengthened with boundary elements. Presence of openings in RC walls significantly reduces base shear carrying capacity in the presence of boundary elements while it reduces both base shear capacity and ductility in the absence of boundary elements. Decrease in the aspect ratio of the wall reduces the base shear capacity of the wall while deformation capacities remain unaffected.