Experimental Study and Comparative Analysis of Shake Table Tests on Metro Stations with or Without Columns in Soil-Rock Combination Strata

As a new type of station structure, the seismic research of long-span column-free metro station is relatively weak compared with the traditional column station, and the seismic characteristics and failure phenomena of these two types of structures are quite different. Therefore, it is necessary to compare the seismic performance of the two structures. In this paper, a large-scale shaking table test was carried out on the large-span column-free metro station structure and the two-layer island subway structure for the typical soil-rock combination stratum in Jinan, and the parameters such as soil-structure acceleration, soil pressure distribution and strain were obtained by numerical simulation. The results show that the maximum acceleration difference between the two types of structures at the middle plate is 13.8%, and the maximum tensile stress at the connection between the bottom plate and the side wall is 11.6%. Under the same geological conditions and seismic waves, the difference of soil-structure seismic response is related to the overall stiffness of the structure. The columns station is more affected by high-frequency seismic waves, while the column-free station is the opposite. Both types of structures meet the general seismic response law, but the column station shows stress concentration at the column-plate connection, which has a better inhibitory effect on the lateral displacement of the surrounding soil. In general, the seismic performance of the column station is about 1/10 stronger than that of the column-free station, but the column-free station can also meet the basic seismic requirements. A model test was designed for the soil-rock-underground structure interaction system.The interaction characteristics of underground structures in soil-rock strata are studied.The seismic response characteristics of subway stations with different structural types in soil and rock strata are compared.