Research On Seismic Performance Of Modular Structural System Based On Mega-frame

Prefabricated modular buildings have the advantages of rapid construction,green environmental protection and high recycling rate,and it is the future development direction of the construction industry.With the increasing number of the population and the increasing demand of urban construction land,buildings must develop toward high-rise and super-high-rise buildings.However,the seismic performance of modular structures in high-rise buildings is still unclear,and there is a lack of relevant research.Mega-frame structure is a super high-rise building system with high stiffness,clear transmission of its force and good seismic performance.The main-structure and sub-structure of the mega-frame structure can adopt two independent structural forms.In this paper,the mega-frame structure with excellent seismic performance is used as the carrier and the prefabricated modular structure is used as the sub-structure to form the Modular Structure System Based on Mega-frame.The finite element software Perform-3D is used to analyze the elastic-plastic time history of the structure under rare earthquakes.The seismic performance of the structure is evaluated comprehensively through the macro-parameters such as base shear,inter-story displacement angle,inter-story lateral displacement and material damage,and get the structural optimization of main-structure and sub-structure based on large earthquake damage control.The work carried out in this paper includes the following aspects.(1)Seismic performance analysis of the Modular Structure Based on Mega-frame is carried out.Based on the experimental research of reinforced concrete mega-frame structure,the Modular Structure Based on Mega-frame model is established after reasonable design.The non-linear time-history analysis of the structure is carried out under large earthquakes.The seismic performance of the structure is comprehensively evaluated through inter-story displacement angle,base shear,lateral displacement and material damage.The results show that the macroscopic indexes of Modular Structure Based on Mega-frame Structure meet the requirements of the code under rare earthquakes.In terms of material damage,serious damage will occur at the joint between the modular in the bottom of the sub-structure,and at the bottom of the main-structure and the intersection of the mega-beam.(2)Damage control of substructures of Modular Structures Based on Mega-Frames is studied.The damage of sub-structures is decreased by Increasing the Bearing Capacity of Joints According to the actual structure,and adding spring devices and metal dampers to the lateral joints between the main-structure and the sub-structure.By comparing the vertex displacement time history,the absolute vertex acceleration time history,the base shear force time history of the main-structure,and vertex displacement,absolute vertex acceleration,base shear force,material damage of the sub-structure,structures of these three are studied and analyzed.The results show that the number of damaged joints can be reduced by 45% by increasing the bearing capacity of the joints;the number of damaged joints can be reduced by 43% by installing metal dampers;the interlayer displacement angle,lateral displacement and base shear force of the whole structure with spring devices have little change,and the number of damaged joints between modules can be reduced by 62% around 104 k N/m in spring stiffness.Adding spring device can reduce the damage most effectively.(3)Damage control of the main-structure of Modular Structure Based on Mega-frame is studied.The truss column is used to replace the traditional reinforced concrete core tube column,and the elastic-plastic time history analysis is carried out under the large earthquakes.The seismic performance of the truss column is analyzed by macroscopic indexes such as vertex displacement,vertex absolute acceleration,maximum base shear force and material damage.The results show that the changes of the vertex displacement and absolute acceleration have little changes,but the structure with truss column is 40% lower than the reinforced concrete structure in the base shear force.And the material damage of members of structure with truss column is much less than that of traditional reinforced concrete mega-frame structure.The superiority of seismic performance of mega-frame structure with truss column is proved.