# Seismic Effectiveness of Multiple Seismic Measures on a Continuous Gider Bridge
## 5 Calculation Analysis and Discussion
### Energy Dissipation
For the laminated rubber bearing, its maximum displacement--10.07 cm--is slightly higher than its allowable shear deformation--9.1 cm--under the action of the large earthquake. Piers #1 and #5 have increasing displacement at their tops and an increasing bending moment at their bottoms, while #2, #3, and #4 piers have decreasing displacement at their tops and a decreasing bending moment at their bottoms. However, all the piers have a similar seismic response after seismic measures are taken. Under the action of the large earthquake, the maximum displacement of the pier tops is 5.57 cm, which is 7.14 times larger than that in Case 1, but the displacement of the pier tops does not exceed the allowable displacement of the piers. The maximum bending moment at the bottom of the piers is 32,803 kN\(\cdot\)m, which is 6.43 times larger than that in Case 1, and slightly more than the ultimate bending moment of the piers. This means that the seismic measures can effectively restrain the relative displacement of the substructure and superstructure of the bridge and reduce the probability of the bounding, unseating and failure damages of the bridge structure under the action of an earthquake. Meanwhile, the seismic measures can dissipate the seismic energy, increase the overall stiffness of the bridge structure, and uniformly distribute the seismic load on the piers. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Earthquakes** & **Positions** & \begin{tabular}{c} **Displacement of** \\ **Grider (cm)** \\ \end{tabular} & \begin{tabular}{c} **Case/Case1** \\ **(\%)** \\ \end{tabular} & \begin{tabular}{c} **Displacement of Pier** \\ **Top (cm)** \\ \end{tabular} & \begin{tabular}{c} **Case/Case1** \\ **(\%)** \\ \end{tabular} & \begin{tabular}{c} **Bearing** \\ **DispleElement (cm)** \\ \end{tabular} & \begin{tabular}{c} **Case \#/Case 1** \\ **(\%)** \\ \end{tabular} & \
\begin{tabular}{c} **Bending Moment of** \\ **Pier Bottom (\&N m)** \\ \end{tabular} &
\begin{tabular}{c} **Case \#/Case 1** \\ **1 (\%)** \\ \end{tabular} \\ \hline Small Earthquake & \multicolumn{2}{c}{Side pier} & 3.83 & 0.98 & 0.21 & 1.00 & 3.62 & 0.98 & 1377 & 1.00 \\ \cline{2-9}  & \multicolumn{2}{c}{middle pier} & 3.83 & 0.98 & 0.89 & 0.98 & 2.93 & 0.97 & 5298 & 0.99 \\ \hline Moderate & \multicolumn{2}{c}{Side pier} & 10.03 & 0.67 & 2.04 & 3.46 & 7.97 & 0.55 & 12,363 & 3.20 \\ \cline{2-9}  & \multicolumn{2}{c}{middle pier} & 10.03 & 0.67 & 2.38 & 0.73 & 7.64 & 0.65 & 14,232 & 0.74 \\ \hline Large Earthquake & \multicolumn{2}{c}{Side pier} & 13.75 & 0.72 & 5.57 & 7.14 & 8.18 & 0.45 & 32,003 & 6.43 \\ \cline{2-9}  & \multicolumn{2}{c}{middle pier} & 13.57 & 0.71 & 3.5 & 0.82 & 10.07 & 0.68 & 20,783 & 0.82 \\ \hline Northridge & \multicolumn{2}{c}{Side pier} & 12.05 & 0.48 & 3.98 & 3.49 & 8.07 & 0.34 & 23,924 & 3.16 \\ \cline{2-9}  & \multicolumn{2}{c}{middle pier} & 12.05 & 0.48 & 2.96 & 0.53 & 9.09 & 0.47 & 17,592 & 0.54 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Seismic responses of bridge under different earthquakes.