The Research On Multi-objectives Optimization Of Precast Concrete Members Temporary Storage Area Layout Planning On Construction Site

Construction site layout planning is an important part of the preliminary design of projects.However,in actual projects,construction managers often make it through experience,which greatly reduce the construction efficiency,or cause unnecessary safety risks and cost waste.With the development of modern information technology,it is the choice of researchers to arrange construction sites by means of automation.Most of the construction site layout planning by considering the transport distance or cost,safety and other factors to establish a model for the site temporary facilities layout.Nowadays,with the rapid development of industrial construction,prefab buildings require less labor,have a fast construction speed and low production cost.However,the construction process and material characteristics of prefabricated building construction projects are quite different from those of general buildings,so the layout of precast concrete components on the construction site cannot fully apply the model and method of general layout of building site.This paper through the literature analysis method from the construction layout of important influencing factors,and the factors associated with precast unit yard screening and classification,and then summarized according to the factors affecting the classification yard layout optimization goal,precast concrete components,respectively,for horizontal transport time,Length of horizontal lifting path for member,hazards risk value.Based on this,this paper establishes a multi-objective optimization model of temporary storage yard planning of precast concrete components.Firstly,the size and area of the storage yard in each construction stage are estimated by the surrounding box technology and related specifications,and then the assumptions,related parameters,optimization objectives and constraints are set up according to the mathematical model method.Finally,the effectiveness of the model was verified in an assembly-type project in Chongqing,and the multi-objective genetic algorithm NSGA-Ⅱ was selected for simulation.Finally,the optimization result of yard layout of the example was obtained.The research results of this paper show that the precast concrete component yard is different from other temporary facilities in that it should be arranged according to the real-time schedule and production logistics plan due to its dynamic and variability in the construction process.The multi-objective optimization model established in this paper is fully combined with the characteristics of assembly-type projects,and the factors affecting the construction layout are considered comprehensively.Finally,the simulation is carried out in a real assembly-type project case,and the experimental results show that the optimization scheme is optimized by 10%-20% compared with the original layout objectives,and the effectiveness of the model is verified from the aspects of efficiency and safety.