| Land resources is the core and foundation of the national economy sustainable development,the reasonable development and utilization of land resources is a vital event.With the acceleration of industrialization and urbanization,the contradiction between the increasing social demand of land and the limitation of land resources and the irreversible land use is increasingly significant.The development of multilayer long-span public and industrial buildings,improve the utilization of land resources.the development of new structure system is the key initiatives.This paper presents a new type of structure system,which is suitable for the multilayer long-span public and industrial buildings,namely multilayer long-span orthogonal and ortho-laid steel grid box structure.This new type of structural system has good mechanical performance and wide application space,especially in the public and industrial buildings,saving materials,providing greater using space,but also to solve the current problems of land use,and has been applied to more than a dozen practical projects.The engineering practice shows that assembly units of this new structure are processed in the factory,transported to the site,and connected by high strength bolts.So it can improves the construction progress and the degree of civilization construction,reduced the cost of construction,and the high precision of the processing level of the project also provides a reliable guarantee for the quality of the project.Based on the method of combining the experimental research and theoretical analysis,the static analysis,seismic analysis,modal and comfort analysis and progressive collapse analysis of the multilayer long-span orthogonal and ortho-laid steel grid box structure are conducted.The main research of the thesis includes:(1)The main structure characteristics of the steel concrete composite open web sandwich plate are introduced in detail,and equivalent sandwich plate method is used to make the continuous derivation of the sandwich plate.By comparing with the results of finite element analysis,the results show that the method has higher precision.A simplified method for calculating the open web sandwich plate is presented.Through the contrastive analysis,it is proved that the method is efficient,safe and widely used.(2)The main structural characteristics of the steel grid frame wall are introduced in detail.Based on the mechanism of the frame,the lateral stiffness of the steel grid frame wall is obviously better than that of the conventional frame structure.The inflection-point method and energy variation method are used to derive the lateral displacement calculation formula of the steel grid frame wall,and the finite element comparative analysis shows that the derivation process has higher accuracy.(3)The simulation model hysteresis test of a steel grid frame wall in practical engineering shows that the failure mode of the steel grid frame wall is the local damage caused by the external buckling of the T beam at the top of the wall.The test results of the steel grid frame wall's hysteretic curve,skeleton curve and ductility coefficient show that it has good bearing capacity,energy dissipation capacity and deformation capacity,and the seismic behavior is good.By means of parametric finite element analysis,it is showed that the section stiffness increase of the two top T beams and columns can improve the ultimate bearing capacity and ductility of the steel grid frame wall effectively,and the section stiffness of columns is more obvious.The section stiffness of the two layer H type interlayer beam has little contribution to the bearing capacity and ductility of the wall frame.(4)The comparative analysis of earthquake resistance between box structure and conventional frame structure of Nanjing multifunctional office was conducted.The analysis results of cantilever mode response spectrum,elastic time history analysis and elastic-plastic time history analysis show that the box structure in the premise of steel to reduce the amount of 15.070%compared with the conventional frame structure has better seismic performance.(5)The Guizhou Province Museum 5D hall mode testing show that the fundamental frequency of the orthogonal and ortho-laid open web sandwich plate is lower,natural frequency is relatively dense,and the open web sandwich plate is a type of mode intensive structure.The parametric analysis shows that the span-depth ratio and hollow ratio has obvious influence on fundamental frequency.Based on the fundamental frequency regression analysis,the expression between the fundamental frequency and span-depth ratio and hollow ratio was deduced.It provides great convenience for the use of the orthogonal and ortho-laid open web sandwich plate in practical engineering.(6)The comfort testing of Guizhou Province Museum 5D Hall is conducted.By summarizing a large number of single and multi person walking incentive condition test results,the most adverse conditions are found,and a series of preventive measures and strengthening for engineering application are proposed.The finite element analysis results are in good agreement with the experimental data,and the acceleration peak of all conditions meet the requirements of the ISO standard and Technical specification for concrete structures of tall building in China.It shows that the overall stiffness of the floor is large,at the same time also shows that the proposed method of floor comfort has very good practical value.(7)By using dismantling component method,the comparative analysis of progressive collapse analysis between box structure and frame structure of Nanjing multifunctional office was conducted.From the change of axial force of the bottom left frame column and the maximum vertical displacement of the failure point,it is proved that box structure with a 15.07%reduction in the amount of steel has a stronger ability to resist progressive collapse than conventional frame structure. |
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