A new ground motion intensity measure IB

In this study, a new generalized ground motion intensity measure is proposed. The new intensity measure named IB is able to increase the efficiency in the prediction of nonlinear behavior and higher modes effects of structures subjected to earthquake ground motions with different characteristics. The intensity measure is based on a recently proposed proxy of the spectral shape named Np, which has been successfully used in ground motion record selection for nonlinear dynamic analysis. Although the Np parameter was proposed by using the spectral shape in term of pseudo-acceleration, it will be observed that Np can be defined through other types of spectral shapes such as those obtained with velocity, displacement, input energy, inelastic parameters and so on. In addition, it is illustrated that several ground motion intensity measures are particular cases of the new generalized ground motion intensity measure here proposed, which is able to predict both nonlinear structural demands and higher modes effects on buildings under earthquake ground motions.