Research On Selection Design And Construction Scheme Optimization Of Long Span Steel Grid Structure

Large-span spatial structure is an important symbol to measure the development of national building science and technology level.The grid structure has become one of the fastest-growing forms of space structure due to its beautiful shape,strong bearing capacity,high safety,and economical rationality.It is widely used in public infrastructure buildings such as stadiums,airport terminals,exhibition centers,grand theaters and so on.With the development of space truss structure,various problems have been brought to the structural design and construction due to the increasingly complex form,larger span and scale.In order to more scientifically and rationally determine the structural form,optimize the best construction plan,and provide a systematic and feasible method for the management of the grid structure from design to construction process,this paper combining with various technical means such as spatial steel structure design software,building information modeling(BIM)technology,non dominated sorting genetic algorithm-Ⅱ(NSGA-Ⅱ)for long-span space truss structure type selection,design and construction scheme optimization is studied.The specific contents include:(1)Extensively consult relevant literature,sort out the development and application of large-span grid structure,analyze the research status of large-span grid structure in design and construction,and clarify the basic theory and method of grid structure selection design and construction scheme optimization in this paper.(2)Based on the comprehensive evaluation method,a comprehensive evaluation model for the selection of large-span steel grid structure is constructed.Firstly,on the basis of analyzing the influencing factors of grid structure selection and the original data obtained by 3D3 S spatial steel structure design software modeling,analytic hierarchy process is used to construct the selection evaluation index system of long-span steel grid structure,determine the weight value of each index.Then use the grey evaluation method to calculate the correlation value of each scheme,and determine the optimal grid structure form.(3)Based on the grid structure form determined by design and selection,BIM technology is used to establish three-dimensional information model diagram.Summarize the common construction methods of large-span grid structure,draft alternative construction methods according to the characteristics of the project.Through virtual simulation of construction scheme and analysis with Work Breakdown Structure(WBS)technology,basic data information was obtained,and then quantitative analysis was carried out to establish the multi-objective optimization mathematical model of long-span steel grid structure.NSGA-Ⅱ algorithm was used to solve the model and Pareto solution set was obtained.Finally,the Pareto solution set was optimized based on grey correlation analysis to determine the best construction scheme for grid structure installation.(4)Taking the reconstruction and expansion project of an airport terminal as the research object,the feasibility and effectiveness of the comprehensive evaluation model of space truss structure selection and the optimization model of construction scheme are verified,which provides a method support for scientifically and reasonably determining the form and installation scheme of long-span steel space truss structure.