Analysis on Dynamic Interaction of Subway Station-soil-aboveground Frame Structure Under Inclined Incidence of SV Wave

Dynamic interaction between subway station structure and adjacent building under the action of earthquake has been given much attention. However, the analysis of interaction under oblique incident seismic wave is still lacking, and the relevant laws are not clear. In this paper, based on viscoelastic artificial boundary, finite element model of the whole dynamic system of subway station-soil-aboveground frame structure is established, free field seismic response analysis method by means of the frequency domain stiffness matrix is adopted to obtain the seismic input under the action of oblique incident SV wave at any angle, and dynamic response law of the subway station-soil-aboveground frame structure system is analyzed by taking the incidence angle, the space between the aboveground and underground structures, the site category into account. It is found that: (1) The existence of aboveground structure will significantly increase the axial force amplitude of central column of station structure, when the aboveground frame structure is close to the station structure, axial force amplitude of the central column can be increased by up to 7.3 times, and this increase effect will change the variation law of the axial force amplitude with the incident angle, generally, the axial force of central column of the station has a considerable amplitude when SV wave is vertically incident and when it is about 10° higher than the critical angle. (2) The influence of the aboveground frame structure on the story drift ratio of subway station is closely related to the site conditions, in hard site (class Ⅱ site), the story drift ratio of station is amplified by 74% at the highest, and in soft site (class Ⅳ site), the story drift ratio of station is reduced by 30% at the lowest. (3) The existence of subway station structure can amplify the story drift ratio of aboveground frame structure, generally, the closer the subway station is to the aboveground building, the more obvious the amplification effect is, and the story drift ratio of aboveground frame structure can be amplified by 52% at most. It is suggested that cases of 0° incidence and the supercritical angle incidence, which is about 10° higher than the critical angle, should be considered as the unfavorable condition for seismic response analysis of aboveground or underground structures.