Two-Dimensional Seismic Response Analysis to Evaluate the Site Effects of the New Belvedere Bridge (L’Aquila, Central Italy)

To evaluate the importance of the site effects of large structures such as the new Belvedere Bridge (L’Aquila), which crosses a 25 m deep and 100 m valley in the city, one-dimensional and two-dimensional analyses were used to model the seismic response. The results indicate that the valley effects and the geometry of the bridge construction section have a significant influence on ground motions, especially at the points where the natural morphology has been altered by civil works carried out over time. In the presence of vertically propagating shear waves (SVs), the synthetic parameters of seismic motion, such as the maximum ground acceleration (PGA), the amplification factors (AFs), and the elastic acceleration response spectra (Ses), are crucial aspects to identify. The different motions generated between the anchorage points of the bridge foundations, even though they exhibit reduced proportions, and the site effects should be considered in bridge design.