R-Factor for 10 Storey IMRF Building with Shear Wall

Abstract

In the earthquake resistant design of a structure the term response reduction factor R plays a critical role as it reduces the design elastic seismic demand of the structure. This response reduction factor R incorporates the reserve strength of the structure and its ductility. As per the philosophy of earthquake resistant design the behavior of the structure is governed by its ability to deform in the inelastic zone. This inelastic deformation ability of the structure is indirectly taken into account with the help of this response reduction factor in various seismic codes and guidelines. The value of R given by various existing guide lines is based upon observed structural behavior in the previous earthquakes. In the research presented here focuses on estimating the value of response reduction factor R analytically for10 IMRF (Intermediate moment resisting frame) building with shear walls designed and detailed as per IS 456 (2000), IS 1893 (2016) and IS 13920 (2016) Draft report. In this study a 10 story building with shear wall founded on hard rock in seismic zone 3 is considered with detailing in accordance with IS13920:2016 Draft report. For the correct estimation of strength and behavior of the structure from the nonlinear pushover analysis confinement modeling of the structure is required. In this work, Mander's confinement model is used for concrete within ties/stirrups in order to provide an accurate estimation of the structure's behavior. Two different load patterns i.e. fundamental loading and IS load distribution is used for comparative study. The R-factor calculated for the examined frame building was found to be close to the R-factor calculated during the design.