Comparative Analysis And Research On The Prefabricated New And Old Concrete Structure Systems Of Multi-story And Large-span Buildings

With the increasing shortage of land for construction,new buildings are rapidly developing in the direction of multi-storey and high-rise buildings.Public and industrial buildings with multi-story and long-span structures can improve land use efficiency.On this basis,Academician Ma innovatively proposed a new structure system--reinforced concrete space grid box structure.The structure has the advantages of flexible space division,large lateral stiffness and significant economic benefits,and has a broad application prospect.Reinforced concrete space grid box structure is a new type of space grid structure system,which is composed of open-web sandwich floor and grid wall frame.In order to study the performance of box structure,its basic structure and analysis method are studied.The natural vibration characteristics and comfort degree of open-web sandwich floor are analyzed.The results show that the low order vibration modes of the open-web sandwich floor are mainly vertical vibration.The ratio of span height,the rate of hollow,the size of grid and the side length of dense column have great influence on the basic frequency of floor.The floor meets the comfort limit of frequency and acceleration.The comfort of open-web sandwich floor is better than that of primary and secondary beam floor.In order to investigate the superiority of the box structure,a multi-storey long-span industrial plant is compared and analyzed.The results show that the box structure is superior to the traditional frame structure in terms of lateral stiffness,inter-storey displacement,stress,isolation performance and economic and technical indicators.In order to improve the construction quality,accelerate the construction speed and reduce the construction cost,the assembly construction method of box structure was studied.The prefabricated elements are assembled by means of sleeve connection,and finally the connection is poured to form the structure.Assembly construction is beneficial to the popularization of the box structure.In summary,the prefabricated reinforced concrete space grid box structure has better mechanical properties and economic benefits,comprehensive performance is better than the traditional frame structure.It has a good prospect for development.