## 6 Conclusions  
In this paper, for continuous girder bridges vertically spanning a strike-slip fault, we take both the location and degree of fault misalignment as the starting point. Based on the quantified structural seismic response, the effect of lateral collision on bridges near/across faults is revealed. On this basis, parametric analyses of collision stiffness and initial clearance are carried out to rationally regulate the internal force and displacement responses of bridges spanning faults. The main conclusions are as follows:  
1. Compared with the near-fault bridge, the lateral collision has a greater effect on the cross-fault bridge. The amplification of the maximum bending moment of the middle pier and the limitation of the maximum displacement of the bearing are five times and two times that of the near-fault bridge, respectively. At the same time, the lateral collision also amplifies the torsional characteristics of the cross-fault bridge. Therefore, the risk of local failure of the middle pier of the cross-fault bridge under the action of lateral collision is much higher than that of the near-fault bridge. 2. With the increase in the average slip displacement of the fault from 40 cm to 80 cm, the existence of transverse collision leads to an increase of 94.5%, 61.9%, and 57.6% in the torque at the bottom of the pier, the bending moment at the bottom of the pier, \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Torque/(kN\(\cdot\)m)** & **Bending** & **Bearing** \\  & & **Moment/(kN\(\cdot\)m)** & **Displacement/(cm)** \\ \hline Condition C & 17,094 & 42,598 & 38 \\ Condition D & 19,886 & 75,472 & 14 \\ Condition E & 21,436 & 52,844 & 23 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of the seismic response of the middle pier of the bridge across the fault before and after parameter adjustment. and the displacement of the bearing. Its amplification effect on the bending moment at the bottom of the pier is 2.06 times that without collision. When the bridge is faced with large fault dislocation, the bending effect of the pier should be considered first to avoid bending failure caused by an excessive bending moment. Secondly, we should also pay attention to the residual torque of the pier after the earthquake to prevent the secondary torsion cracking of the pier. 3. The variation of parameters related to the collision effect shows that the influence of the transverse collision parameters on the pier bottom torque of the cross-fault bridge is not obvious, and it is only 3.3% affected by the collision stiffness. By properly reducing the collision stiffness and increasing the initial gap, the amplification effect of the transverse shear key on the bending moment of the pier bottom can be improved, and the bearing displacement also has high redundancy. Therefore, the selection of reasonable collision parameters can effectively control the seismic response of cross-fault bridges. In short, the change in fault dislocation position and dislocation degree will greatly affect the lateral collision effect of the bridge. The improvement effect of the shear key with conventional parameters on the seismic response of the fault-crossing bridge is polarized. It is necessary to select the relevant parameters reasonably to realize the equalization of the stress state of the bridge across the fault. However, this study simulates the restoring force model of the laminated rubber bearing in a linear form and does not consider the damage state of the shear key. Therefore, the further research focus is to consider the influence of the friction slip characteristics of the plate rubber bearing and the degradation of the mechanical properties of the transverse shear key on the transverse seismic response of the cross-fault bridge and put forward the reasonable parameters suitable for the design of the transverse shear key of the cross-fault bridge. Conceptualization, Y.H. ; methodology, L.F.; software, L.F.; writing--review and editing, L.F.; visualization, J.L. ; Funding acquisition, Y.H.