| Large-span spatial hub structure is an important urban lifeline project.Once it is damaged under earthquake,it will cause immeasurable casualties and property losses.Different from the traditional large-span spatial structure,the hub structure has a lower structure with high stiffness besides the upper roof structure,and the overall structure form is complex.Therefore,it is of great significance to analyze the cooperative work of the large-span spatial hub structure and study the response law and mechanism of the overall structure under the earthquake action,so as to ensure the seismic safety of the hub structure and promote the national economic development.In this paper,taking the large-span spatial hub structure as the research object,the seismic response law and mechanism of the large-span spatial hub structure considering the cooperative work of substructure and the soil structure interaction are studied.The main work and research results of this paper are as follows:(1)The typical large-span space pipe truss hub structure and the large-span space truss hub structure are selected.The overall structure finite element model considering the substructure and the soil structure interaction are established by using ABAQUS.(2)The influence of substructure cooperation on the seismic response of largespan space truss hub structure and pipe truss hub structure is studied,and the plastic development law of large-span space truss hub structure under strong earthquake is further studied by using incremental dynamic analysis method.The results show that the natural frequency of the hub structure considering the substructure is significantly lower than that considering only the roof structure,and the maximum difference of the first ten natural frequencies is about 20.2%.Considering the effect of substructure,the dynamic response of the roof increases obviously.Compared with the roof structure,the three-dimensional acceleration response of the roof joint increases by15.8%～248.6%,the three-dimensional relative displacement response of the joint increases by 3.8%～453.1%,and the stress of the member increases by 0.1%～125.1%.Under the action of strong earthquake,the ratio of yield members of space truss hub structure and pipe truss hub structure increases approximately linearly with the increase of seismic acceleration peak value.(3)The influence of soil structure interaction on seismic response of large-span space truss and pipe truss structures is studied.The results show that the natural frequency of the hub structure decreases when considering the interaction between soil and structure,and the maximum difference of the first ten natural frequencies is about7.7%.Considering the soil structure interaction,the three-way acceleration response of the roof joint of the hub structure will be reduced by about 0.6%～39.9%,and the threeway displacement response of the roof joint will increase by about 0.7%～29.6%.The stress of the most key members with high stress in the roof of large-span spatial hub structure decreases by about 0.1%～41.8% after considering the soil structure interaction,and the stress distribution of the members is more uniform. |
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