Evaluating A New Proxy For Spectral Shape To Be Used As An Intensity Measure

The possibility to use a new vector‐valued ground motion intensity measure (IM) is analyzed; it is based on the spectral acceleration at first mode (Sa) and a parameter proxy for the spectral shape, namely Np. The potential of the vector 〈Sa,Np〉 is explored by efficiency comparison with other IMs. It will be illustrated how the form of the vector 〈Sa,Np may represent an improvement in predicting the seismic response in terms of ductility, dissipated hysteretic energy and Park and Ang damage index for nonlinear single degree of freedom (SDOF) structures subjected to ordinary, narrow‐band and near‐source pulse‐like records.