Horizontal Seismic Peak Acceleration Propagation within Gorge and Mountain Site

The numerical dynamic model of a given gorge and valley site is established, and the depth and topographic effect of horizontal peak acceleration under some given seismic record is researched. Furthermore, the effect of various parameters of gorge site on propagation characteristics is analyzed. The numerical simulation results indicate that horizontal peak acceleration (HPA) falls with depth, smaller at slope toe than at model bottom; the HPA is amplified at mountain top, but smaller than practical seismic record. The attenuation effect rises with model depth and damping ratio, but decrease with slope ratio. The attenuation degree will increase if the predominant frequency of seismic input approaches the natural frequency of gorge and valley site.