The Research On Greenness Improvement Of Prefabricated Buildings Based On System Dynamics

Green development is an important concept of social and economic development as determined "13th Five-Year Plan" of China.It is the trend of the construction industry to develop green buildings and improve the greenness of buildings.Prefabricated buildings are the main part of green buildings with the characteristics of "four energy conservation,one environmental protection".Based on the concept of sustainable development,it is imperative to develop prefabricated buildings.At present,there is no scientific and comprehensive guidance document about the relevant greening standards for green buildings and fabricated buildings;greenness is a measure of the degree to which green building products meet green characteristics,and is also a comprehensive expression of environmental friendliness;Improving greenness is an effective measure to reduce the output to the environment and increase the input to energy.It can meet the material and cultural needs of the current society without damaging the quality,cost,function and energy efficiency.It is of theoretical and practical value to carry out research on the greenness improvement of fabricated buildings.This thesis analyzes the literature on the factors affecting greenness of fabricated buildings and greenness improvement at home and abroad.The greenness influence elements are longitudinally combed in the order of the entire life cycle of the prefabricated building.Incorporating the expert interview method to screen the influencing factors,and finally combing and determining the final list of the factors affecting the greenness of the fabricated building.After classification,the nine categories of internal factors are obtained:environmental function level,economic function level,social function level,resource consumption level,environmental protection level,engineering production level,project management level,construction cost level,and maintenance cost level;external factors:social assembly building green values,policy and legal support.Finally,based on the system dynamics to solve the advantages of complex system problems,the system dynamics causality diagram is drawn according to the correlation and logical relationship between variables.The triangular fuzzy number method is used to assign weights to relevant parameters in the system model,and the flow chart of the dynamic model of the fabricated building green degree system is constructed.The diversified analysis method combining qualitative and quantitative is used to simulate the greenness model of the assembled building.The system dynamics software Vensim PLE is used to simulate the single element intervention simulation,and finally the critical loop of the positive cycle of the prefabricated building greenness improvement path and five key factors affecting the maximum degree of greenness of prefabricated buildings which including resource use efficiency,application level of new construction methods,mechanization,carbon emissions,industrial structure and transport development level are obtained.Therefore,countermeasures are proposed from five aspects,which provide reference for the government,investment department and relevant researchers to formulate reasonable intervention policies,and provide some scientific and theoretical basis for the improvement of the greenness of the prefabricated buildings and the development of related industries.