## 5 Seismic Risk Assessment of Novel SCPC Frame  
### Overall Responses to Near-Fault Earthquakes  
Nonlinear time-history analysis is applied to the five-story four-span novel SCPC frame numerical model at the DBE and MCE earthquake levels using OpenSees software. The horizontal seismic influence coefficient of the prototype frame at the DBE and MCE levels are 0.117 and 0.234 calculated by the seismic intensity, site category, design earthquake grouping, the fundamental period and damping ratio according to Chinese Standard Code [29]. The gravity load of each story is evenly distributed at the central node of the core area of the beam-column connection. In order to calculate the residual deformations of the novel frame, 20 s last-time free vibration analysis of the structure continued after applying each near-fault ground motion action. From the aforementioned analysis results, the peak inter-story drift ratios and peak residual inter-story drift ratios are selected as the main evaluation index to define IO and RE limit state under the near-fault earthquake wave loadings. Figure 13 displays the top floor displacement time-history curves of the near-fault earthquake waves NO.10-LGP090, NO.13-H-E04230, NO.18-CPM090 respectively. The peak value of top floor displacements are 23.5 mm, 20.8 mm and 32.4 mm under the DBE level and the peak value of top floor displacements are 54.2 mm, 46.7 mm and 69.8 mm under MCE level, respectively. The peak value of top floor displacements occur about in 11 s, 7 s and 4 s for the above three waves, which indicates the displacement responses of the frame are relatively large at the beginning and the displacements reduce significantly because of the self-centering capability for the novel SCPC frame. Hence, the final residual displacements for the novel frame are minimal under each ground motion. The final residual top floor displacements for the precast frame are 0.23 mm, 0.15 mm and 0.41 mm for NO.10-LGP090, NO.13-H-E04230, NO.18-CPM090 under the MCE level, respectively. The maximum top floor displacements, the times the maximum response occurs and the residual top displacements under 21 earthquake waves are all listed on Table 2. The above analysis results present the novel SCPC frame has greater lateral stiffness and good self-centering capability, the top floor displacement responses are in a reasonable range under DEB and MCE levels. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Number**} & \multirow{2}{*}{**Ground Motion**} & \multicolumn{2}{c}{**Max Top Displacement**} & \multicolumn{2}{c}{**Max Top**} & \multirow{2}{*}{**Residual Top**} \\  & & **(DBE) (mm)** & & & **Displacement** & \\  & & **mm(mm)** & & **(MC) (mm)** & & **(mm)** \\ \hline  
L360 & 25.3 & 7.3 & 55.1 & 7.4 & 0.23 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Maximum top floor displacements under 21 ground motions. The peak inter-story drift ratios for each earthquake wave and for each story subjected to DBE and MCE levels under the near-fault ground motions are displayed in Figure 14. The maximum seismic  
Figure 13: Time-history curves of top floor displacement-time history curves under design basis earthquake (DBE) and maximum considered earthquake (MCE). responses for each floor, such as inter-story drift ratio, residual inter-story ratio, inter-story shear force and connection relative rotation, are the average values of the peak responses under 21 earthquake waves. The peak inter-story drift ratios of the novel frame are 0.72% and 2.03% corresponding for 21 near-fault earthquake waves at the DBE and MCE levels, respectively. The mean value of peak inter-story drift ratios of the frame for 21 earthquake waves are 0.34% and 0.81% subjected to the two levels, which are below the limiting requirements. The peak inter-story drift ratios for each story happen on the second story under the two seismic levels. The maximum responses from the third and the fifth story are equal to 0.29%, 0.22%, 0.15% at the DBE level and 0.68%, 0.51% and 0.29% at the MCE level, respectively.