RESEARCH ON SEISMIC RESPONSE CHARACTERISTICS OF HUB STRUCTURES

The hub station structure is generally composed of a large-span roof structure and a lower concrete frame structure, and it also contains non-structural components such as piping system. It is of great significance to study the seismic response characteristics of the complex hub station structure under the influence of multiple factors to ensure its seismic safety. 4 typical hub station structures are selected and the finite element method is used to analyze their seismic response characteristics. The results show that the hub station structures are characterized by 'upper flexibility and lower rigidity'. The seismic responses of the hub station structure are amplified twice from the bases to the tops of the roof structures. The roof structures are vertical earthquake sensitive, and the distribution pattern of inter-story displacement of the lower frame structures is different from that of the common frames. After considering the soil-structure interaction, the self-oscillation frequency of the hub structure is reduced, the deformation of the hub roof structure is increased, and the stress distribution of the bars tends to be uniform. For different hub station structures, the focal mechanisms of the most unfavorable ground motions are different. The adverse effect of seismic traveling wave effect shall be considered for lower frame structures, and the traveling wave effect may not be considered for the roof structures. The seismic response of the pipeline system has undergone three amplifications from the base of the hub station structure to the pipeline system. The seismic performance analysis of the pipeline system in the hub station must consider the amplification of the seismic response of the pipeline system by the main structure.