Shaking table test of the effect of an enclosure structure on the seismic performance of a prefabricated subway station

Abstract

The enclosure structure is an indispensable part of the construction system of the prefabricated subway station structure (PSSS), and has a significant impact on the overall mechanics and deformation performance, soil-structure interaction, seismic performance and damage characteristics of the PSSS. In order to study the effect of the enclosure structure on the seismic response of the PSSS, a series of large-scale shaking table tests of a PSSS with and without an enclosure structure were carried out to study in detail the seismic response characteristics of the model system, such as macroscopic phenomena, acceleration, strain, and joint deformation. Then the mechanism of the enclosure structure in strengthening the seismic performance of the PSSS was revealed. Finally, the seismic damage evolution mechanism of the PSSS with the enclosure structure was explained systematically. The results showed that the PSSS with the enclosure structure had good seismic performance, and the collaborative seismic design of the enclosure structure and PSSS should be paid attention to. The acceleration response of the foundation soil and PSSS increased due to the existence of the enclosure structure, but the enclosure structure effectively improved the deformation resistance and joint stiffness of the PSSS and reduced the local stress concentration of the structure. The enclosure structure and the prefabricated structure together constituted a complete structural system to resist earthquake action, and could effectively reduce the seismic damage to the PSSS. Under an extreme earthquake, the PSSS degenerated into a three-hinged arch structure, and still had a certain self-balancing performance, which made it less prone to serious damage such as overall collapse. The research conclusions could provide a scientific reference for the design and construction of PSSS.