Evaluation of response reduction factor by pushover analysis

Estimation of seismic forces plays a vital role in the design of the structure and generally these forces are computed using the linear static method with aid of response reduction factor. Response reduction/modification factor (R) incorporates the nonlinear response of any structure during a seismic event, allowing the designer for a linear force based design while reckoning the nonlinear behaviour and deformation limits of the structure. This research focuses on estimation of the response modification factor for realistic RC moment frame buildings laid out as per norms mentioned in the Indian standard. The importance is given to computation of R at a rather component-wise level with the effects and consideration included by various analyses. The result shows that the value suggested by IS1893 focuses upon a general consideration for the value of R which actually shall vary with a storey height of the structure, thus the value of R being either underestimated or overestimated.