## 9 Conclusions  
Based on the semi-active control theory, this paper designs a semi-active control system for a three-span PC continuous girder bridge with CSWs, a semi-active control system program of the composite structure is written using MATLAB to study its damping performance, and the following conclusions are obtained. The parameters of vibration absorption effect of active control system of PC continuous girder bridge with CSWs are studied, and the weight matrix coefficient \(\alpha\) is reasonably determined. The use of this coefficient gives the composite girder bridge active control system better vibration absorption effect and economy. The semi-active control system of PC continuous girder bridge with CSWs is established, and its vibration absorption effect is studied. The results show that the dampers' energy consumption in the semi-active control system of the composite bridge is the minimum under the semi-active control algorithm of boundary Hrovat. In terms of peak vibration absorption effect of structure, the vibration absorption effect of the semi-active control algorithm of boundary Hrovat is closest to that of an active control algorithm, and the semi-active control algorithm of boundary Hrovat can effectively control the structural vibration response of the PC continuous girder bridge with CSWs. Under the action of El Centro waves, the semi-active control system of the PC continuous girder bridge with CSWs can effectively reduce the structural response of composite girder. The research shows that the average vibration rate absorption of the girder displacement is 71%, while the average vibration reduction rate of the girder acceleration is 20%. Under the action of El Centro waves, the semi-active control system of PC continuous girder bridge with CSWs can effectively reduce the structural response of internal forces at the bottom of composite girder piers. The results show that the average vibration rate  
Figure 7: Time history curve of pier internal force under El Centro seismic wave: (**a**) #2 pier bottom bending moment time-history curve; (**b**) #2 pier bottom shear time–history curve; (**c**) #3 pier bottom bending moment time–history curve; (**d**) #3 pier bottom shear force time–history curve. absorption of bending moment and shear force at the bottom of pier #2 is 70%, while that of pier #3 is between 42% and 48%. The establishment of a semi-active control system for PC continuous girder bridges with CSWs and the study of its seismic control performance provide some reference for the design of seismic isolation for the composite structure bridge with CSWs. In this paper, only El Centro wave excitation is used to study the vibration absorption performance of the semi-active control system of PC continuous beam bridge with CSWs. Next, the vibration absorption performance of the semi-active control system of the composite bridge with CSWs under seismic wave excitation with different spectral characteristics will be studied. Moreover, the nonlinear response of the composite bridge under seismic action will be further considered to further verify the applicability of semi-active control system of PC continuous girder bridge with CSWs to vibration absorption effect. Conceptualization, S.Z. and M.Z. ; data curation, Q.S. ; formal analysis, C.G. ; funding acquisition, S.Z. and M.Z. ; software, H.Z. ; validation, Q.S. and H.C.; writing--original draft, M.Z. ; writing--review and editing, C.G. and H.C. All authors have read and agreed to the published version of the manuscript. This research was funded by the National Natural Science Foundation of China, grants No. 52068025 and No. 51968024, and partially by the Project of Post-graduate Innovation Fund of Jiangxi Province, grant number No. YC2021-S438. Not applicable for this in vitro study. Not applicable. Data Availability StatementData available on request from the authors.