Effects of near-fault pulse-type ground motions on high-speed railway simply supported bridge and pulse parameter analysis

Based on an innovative high-speed railway simply supported bridge (HSRSSB) model, the potential influence of near-fault pulse-type ground motions on HSRSSB is analyzed. Eighty-five original records of such ground motions are imposed on the simulation model. The dynamic responses of the bridge are calculated, including girder displacement, rail displacement, pier bending moment, bearing deformation, and residual displacement. Linear regression analysis reveals the relationship between the dynamic response and intensity measures (IMs). Moreover, six typical ground motions are chosen from these eighty-five records as prototypes in order to perform a pulse parameter analysis. Through an artificial ground motion synthesis, the effects of parameters, such as pulse amplitude, pulse period, and pulse number, on the behavior of HSRSSB are investigated and discussed. It is concluded that the response of HSRSSB depends on the acceleration-type IMs and presents a strong linear relationship with spectral IMs at the fundamental period of the structure. Regarding the pulse parameters, the HSRSSB dynamic response shows a positive correlation relationship with pulse amplitude, but a negative correlation with pulse period.