Analysis And Calculation Of Integral Lifting Construction Process Of A Large Span Steel Structure

In recent years,with the gradual improvement of China’s economic level and the breakthrough of building technology,construction of various types of large-span and large volume steel structure is also in full swing.The construction of large-span roof needs to improve the complexity and fineness of the construction control of space steel structure due to the large span,the variety of bearing forms and the large plane size of buildings.Thus,higher requirements for analysis of construction process and renovation of construction technology are put forward.Therefore,the research and application of new installation technology of large-scale and long-span space steel structure has very important practical significance to speed up China’s socialist modernization drive.Taking the new hangar of Xi’an maintenance base of China Eastern Airlines as the research object,the key technology of integral lifting and installation of large-span steel structure is expounded in detail and the stress mechanism and field observation in integral lifting construction of large-span steel structure are discussed and studied.The main research work is as follows:(1)This paper introduces in detail several construction methods commonly used in the installation of large-span space steel structure,such as grid accumulation slip method,grid scaffold slip construction,high-altitude bulk installation method,integral lifting method.Some representative projects using various methods are listed,and the research status of integral lifting construction technology is summarized emphatically.(2)Taking new hangar project of Xi’an Xianyang International Airport China Eastern Airlines as the main research object,the finite element analysis software Midas/Gen 8.0 was used to establish the analysis model.The simulation analysis was carried out from three aspects: design state,fully synchronous overall lifting state and asynchronous lifting state considering displacement difference.The influence of temperature and wind load on the mechanical performance of roof structure during the whole lifting process is discussed.(3)The whole lifting scheme is introduced and analyzed in detail.The process of truss structure installation,grid structure installation,longitudinal expansion installation,integral lifting and high-altitude installation are described respectively,which provides detailed information for the construction technology of large-span steel roof.In order to ensure the safety of the construction process,the stress of the steel members,the stress of the lifting frame and the lifting members and the settlement of the concrete column during the lifting,closing and unloading of the steel structure are monitored.(4)The stress of long-span steel roof in the process of lifting is totally different from the design state,so the construction mechanics simulation of the lifting process must be carried out.In order to ensure the safety of the lifting process,the influence of asynchronism on the lifting mechanism should be considered.Through the deformation analysis of the above-mentioned most unfavorable lifting schemes and checking calculation according to the current specifications,it is found that the structural components under the condition of asynchronous lifting all meet the requirements of the specifications after replacing some of the members,and the whole lifting process is safe and reliable.