| With the wide development of various sports,conferences,performing arts and other activities in China,the large-span spatial structure has ushered in unprecedented opportunities for development.Through rigid,flexible or combined spatial structure can create beautiful and rich artistic expression of the long-span space building.The novel and complex structure forms also put forward higher requirements for construction technology and construction safety.Integral lifting method has been widely used in the construction of long-span steel structures because of its advantages such as high installation accuracy,good economic benefit and fewer temporary components.Therefore,the research on the integral lifting method and related problems of construction monitoring can not only meet the development needs of China’s construction technology and the safety needs of structural installation,but also promote the development of China’s overall construction industry has a very important significance.Based on the construction process of steel truss installation of Jiangbei Civic Center in Nanjing,this paper mainly studies the following aspects:(1)By summarizing the analysis methods of construction mechanics,the life-and-death element method is determined as the main analysis method in this paper,and the MIDAS/ Gen finite element software based on this method is used as the analysis tool.In comparison with the three construction methods selected,the mixed installation method of overall lifting and scattering is selected,and the installation process and overall lifting scheme of the main steel structure are described in detail.(2)The key technologies in the process of multi-point synchronous lifting were studied,including 12 lifting points,16 lifting points and 24 lifting points were obtained by combining different lifting points for mechanical analysis,and the optimal number and location of lifting points were finally determined.Hydraulic synchronous lifting system and control method;Safety control measures in the process of lifting;The high precision monitoring technology of the static level of the lower lifting point and the control method of the hydraulic hoist cluster are introduced to realize the synchronous lifting control.(3)Midas /Gen software was used to model and analyze the whole construction process,focusing on the structural stage lifting and the overall lifting process.After analyzing the typical conditions of single point and adjacent two points lifting out of sync,the limit of lifting out of sync displacement difference was determined.Random simulation of out of sync of lifting points in two hoisting stages is carried out within the limit.The strength and stiffness of lifting sphanger,limiting device and lifting support structure in the process of lifting are checked and analyzed.Finally,eight representative construction processes are selected for numerical simulation,and the stress and deformation simulation results provide a basis for the formulation of subsequent monitoring programs.(4)Based on finite element analysis summary of the results of the monitoring principle,make the whole process of construction steel truss structure stress and displacement monitoring scheme,monitoring results and finite element simulation of the value,the results show that the stress value of the monitoring and deformation value can satisfy the requirements of specification structure,finite element analysis results are slightly larger than the measured values,but values consistent with the trend of the development of the construction process,The change accords with the actual situation.At the end of the paper,the conclusions of the study are summarized and some problems to be solved in the construction monitoring are prospected.The research work of this paper has accumulated engineering experience for exploring the overall lifting and construction monitoring of multi-lifting point superlarge tonnage,complex and irregular space,rigid and flexible combined steel truss structure. |
PDF Full Text Request