Multi Objective Optimization Model Of Prefabricated Building Construction Considering Learning Effect

Improving the construction efficiency of prefabricated buildings has always been the focus of research at home and abroad.With the vigorous promotion of prefabricated buildings by the state,only during the 14 th Five Year Plan period,the cumulative construction area of prefabricated buildings has reached 1.6 billion square meters,of which the proportion of newly built prefabricated buildings in 2021 has reached 20.5%.However,there is a lack of research on the theory and method of prefabricated building construction in China.The traditional construction theory and method can not adapt to the continuity and repeatability of prefabricated building construction,which has become an important reason restricting the development of prefabricated building.Therefore,improving the existing construction theory and method has adapted to the construction of prefabricated building,which will effectively improve the construction efficiency.Because the characteristics of prefabricated building construction have the basic conditions for the existence of learning effect,and the existing literature rarely studies the learning effect and its influencing factors in prefabricated building construction,the applicability of learning curve theory in prefabricated building is underestimated.Therefore,based on the demonstration of learning effect in prefabricated buildings,this paper will study the impact of learning effect on the construction of prefabricated buildings,and put forward the corresponding scheduling method and multi-objective optimization model considering learning effect.Firstly,by consulting the relevant literature,formulate the standard of data collection,select 8 assembly construction projects with construction and technical representation as the data acquisition object,and extract the data meeting the research requirements in combination with the existing literature and on-site expert opinions.Using the theory of learning effect,verify the objective existence and division of learning effect,analyze the construction characteristics affecting the learning effect of prefabricated buildings,propose a new learning curve improvement model based on the principle of learning curve,and verify the effectiveness of the new model through statistical methods and empirical analysis.The research conclusion shows that there is learning effect in the field of prefabricated building construction,and the learning efficiency of each work is between83%-93%;The three factors that actually affect the learning effect are vertical transportation time,work proficiency and assembly rate.Based on this,an improved learning curve model is proposed.The results show that compared with previous studies,the improved learning curve model is more in line with the expression of the learning effect of prefabricated buildings.Secondly,on the basis of referring to the existing RSM methods,through data analysis and comparison,this paper defines the impact of learning effect on the control process,and comes to the conclusion that the learning effect has a positive impact on the positive control process and a negative impact on the negative control process.Based on this,it integrates the similarities between the CPM control theory and the repetitive process,uses the learning curve model to predict the productivity,analyzes and puts forward the scheduling method suitable for the construction of prefabricated buildings.Finally,the construction period model considering the learning effect and the safety,quality and cost model with the construction period as the independent variable are constructed.Taking a prefabricated building in Guangzhou as an example,the genetic algorithm is used to solve it.It is further concluded that the learning effect has a positive impact on the construction cost,construction period and quality level of prefabricated building,but has a negative impact on the safety level.At the same time,the effectiveness of the model is verified,Combined with relevant evaluation methods,the integration of model optimization and evaluation decision-making is realized,which fully reflects the applicability of the model.The research conclusion of this paper is helpful for the project manager to formulate the construction plan,and improve the labor productivity from the learning curve effect by controlling the influencing factors of the construction stage.At the same time,this paper optimizes the scheduling method and multi-objective equilibrium decision-making model,takes the learning effect as the consideration factor,and improves the adaptability and practicability for the construction of prefabricated buildings.