Multi-objective Optimization Of Space Steel Grid Structure In EPC Mode

Spatial steel grid structure is widely used because of its many advantages.Structural optimization is the first problem to be solved in the application of space steel grid structure.Structural optimization is of great significance to reduce the project cost,shorten the construction period,improve the quality of the project and reduce the construction difficulty.At present,there are some problems in the optimization of the spatial steel grid structure,such as less design variables,less objective function,less constraint conditions,less consideration of the working conditions,and the single level of optimization,there is a certain gap with the actual situation.With the increasing competition in the domestic and international construction market,the construction project management mode is changing.The overall interests of general contracting mode of EPC project to project as a starting point,by the general contractor to design,procurement and construction of integrated management and whole process control,realize the design procurement and construction,fully coordinated,cross depth reasonable convergence,can reduce investment,shorten the construction period,improve the quality of EPC mode with its obvious as one of the main advantages of the development of engineering construction management in the developed countries.At present,China is vigorously promoting the implementation of EPC project general contracting model.This paper tries to discuss the influence of EPC model on the optimization of spatial steel grid structure,and establishes the general mathematical model of multi-objective optimization of spatial steel grid structure.In this paper,we try to improve the method based on the iterative uniform design method,and get the method of multi-objective optimization.The iterative uniform design method has the characteristics of simple operation and fast convergence,but it is not so efficient in solving multi-objective optimization problems.The goal of dimensional multiobjective optimization problems is often not the same,this paper based on the iterative method of uniform design,the goal of dimensionless treatment and then combined with the linear weighted method to construct the evaluation function,the multi-objective optimization problem is transformed into a single objective optimization problem,which is the improved iterative method of uniform Design.The improved iterative uniform design method is simple and easy to operate and has high efficiency,but its subjectivity is very strong.This paper attempts to multi-objective optimization by using the method of game analysis of EPC mode steel space grid structure,according to the similarity of the essence and the theory of multi-objective optimization,the game method based on Nash equilibrium strategy.This method is suitable for the optimization problem with nopreference.At the end of the paper,two methods are used to optimize the design of a single and double-layer reticulated shell under EPC mode,and the effectiveness of the two methods is illustrated.