# Effect Mechanism of Connection Joints in Fabricated Station Structures
## 7 Conclusions  
The dynamic response characteristics of a fabricated station structure with different ground motion characteristics, seismic intensities, and seismic conditions were compared and analyzed. The results showed that the fabricated station structure as a new subway station structure had obvious differences in the structural characteristics compared with the cast-in-place station structure. However, the seismic response of the fabricated station structure was universal under different earthquake actions. The following conclusions were obtained from the numerical results:  
(1) The maximum impact rates of the vault or bottom plate joints on structural failure, interlayer relative deformation, and internal force were 3.2%, 0.7%, and 6.83%, respectively, under the action of different seismic characteristics. The maximum impact rates of the fully prefabricated vault or bottom plate on structural failure, maximum interlayer relative deformation, and internal force of section were 3.05%, 0.17%, and 4.62%, respectively, under different seismic conditions. The maximum influence rates of the fully prefabricated vault or bottom plate on structural failure, maximum interlayer relative deformation, and internal force were 11.26%, 0.92%, and 5.23%, respectively, under the action of different earthquake intensities. The influence of the connection joints in the vault or bottom plate on the seismic response of the fabricated station structure could be ignored. Under the action of an earthquake, the underground structure deformed under the constraint of the surrounding soil. The most serious damage to the prefabricated structure lay in the B-C joints. The joints of the vault and the bottom plate were always in the extrusion state, as  
Figure 19: Compression damage and strength degradation time history of the D–CR joints.  
Figure 20: Compression damage and strength degradation time history of the E–CL joints.  
in the cast-in-place structure. It is recommended that the assembly scheme with fewer prefabricated components is used to improve the construction efficiency under the premise of meeting the requirements of the work site and mechanical capacity.  
(2) The joint damage assessment method proposed in this study quantified the damage degree of dry-type connection joints and visually reflected the seismic response of fabricated station structures. The vertical seismic component significantly influenced the seismic response of the fabricated structures, especially the B-C joint. The vertical seismic component increased the joints' maximum compression damage index by 19% and reduced the residual strength index by 83%. The vertical seismic component increased the axial compression ratio of the sidewalls, which made the damage of the B-C joints more severe. The vertical seismic component should be considered in the seismic design of prefabricated station structures. At the same time, the B-C joints should also be reinforced.  
Although the seismic response of a fabricated station structure with different joint distribution forms was studied and the effect mechanism of connecting joints was clarified in this study, for the optimization of joint distribution, only seismic loads were considered, and the transportation conditions, field production, and mechanical equipment were not taken into account. Comprehensive optimization of the joints not only involves the performance of the joints but also needs to consider the problems of design, construction, and other professional factors, as well as firefighting, waterproofing, and other issues.  
Not applicable.  
The authors declare no conflict of interest.