Research On Construction Safety Evaluation Of Prefabricated Buildings

China is developing prefabricated buildings vigorously.The prefabricated buildings have changed the problems of poor environment,slow construction progress and large labor demand in the construction site of the traditional construction mode.The characteristics of prefabricated buildings make their construction safety management special.The construction safety management and evaluation of prefabricated buildings are carried out,and the existing safety risks are predicted in time to control the occurrence of safety accidents in prefabricated buildings effectively.On basis of the related research,considering the design,component production and other 8 stages,the factors affecting the construction safety of prefabricated buildings are analyzed from five aspects: human,material,management,technology and environment,and the factors affecting the construction safety of prefabricated buildings are identified.Through the questionnaire survey to obtain the similarity between the various factors,using the similarity index to organize and merge the construction safety factors.The construction safety evaluation index system of prefabricated buildings is obtained,which includes 5 first-level indexes of human,material,management,technology and environment,and 42 second-level indexes.Considering the relative importance degree,correlation between indexes and difference among indexes,the AHP method and the improved CRITIC method are used to determine the weight of each index.In order to minimize the distance deviation between the index weights determined by the two methods,the basic idea of TOPSIS method is used to combine the index weights determined by the two methods.Considering the fuzziness and randomness in the process of construction safety evaluation of prefabricated buildings,it describes the safety index information of prefabricated building construction through three digital features: expected value,entropy and hyper entropy.The cloud model evaluation method of determining construction safety evaluation grade by comprehensive cloud closeness is constructed to evaluate the construction safety of prefabricated buildings.The construction safety evaluation model is applied to a prefabricated building project,and the construction safety evaluation grade of the whole project and each index is obtained.The research results show that the project as a whole is in a relatively safe state,but it still needs to pay attention to the technical operation level of prefabricated construction project personnel,temporary support of prefabricated components,deepening the design technology and other safety control.