Research On Safety Risk Assessment Of Hoisting Operation In Prefabricated Buildings

Prefabricated buildings have the characteristics of shortening the on-site construction cycle,reducing the waste of resources,reducing manual work and on-site wet work,reducing environmental pollution,and so on,which get strongly advocated by the national policy and become the primary goal of green low-carbon development.Since China’s prefabricated buildings started late,the relevant technical specifications and management standards are premature,the construction process is risky,the risk of lifting operations step up,the prefabricated components are not standardized,and the quality is not high.In addition,these factors make the lifting construction process of prefabricated buildings prone to safety accidents,especially in high-rise and super high-rise prefabricated buildings,which will cause enormous personal safety losses and economic losses once a safety accident occurs,and so on.Therefore to reduce safety accidents during the hoisting construction phase,a double prevention mechanism is established to avoid unnecessary risks and accurately identify risk sources.It requires a comprehensive and scientific safety risk index system and has significant research to evaluate the hoisting construction safety risks of prefabricated buildings.This paper initiates a safety risk evaluation study on the hoisting construction of prefabricated concrete structure high-rise residences based on a double prevention mechanism.This paper first identifies the "risk sources" by combining the accident causation theory and collects relevant literature to sort out the list of risk factors affecting hoisting construction safety of prefabricated concrete structure high-rise residences.Among them,the initial evaluation index system is constructed from five key dimensions: human factors,physical factors,management factors,environmental factors,and technical factors,respectively.In addition,this paper also designed a questionnaire to be distributed to experts from different relevant sectors to analyze the reliability of the collected data and use it to determine indicators such as importance index and dispersion and to eliminate unreasonable metrics.Based on this,this paper constructs a hoisting construction safety risk evaluation index system for high-rise houses with assembled concrete structures.In this paper,we address the situation that the overly fixed pattern of constant weights causes the results of the evaluated objects to be biased toward safety or danger and combine the theory of variable weights to make dynamic corrections to the permanent weight.At the same time,considering the ambiguity and randomness among the influencing factors of hoisting construction,it is improved based on the object element topologically method.The specific steps are to determine the indicator combination constant weights using the G1-entropy weight method and to determine the variable weight by introducing the theory of variable weight and making dynamic corrections to the optimal permanent weight of the combination.Based on the matter-element extension model,the maximum affiliation criterion was replaced by the closeness criterion to construct the evaluation model for the hoisting construction safety risk of prefabricated concrete structure high-rise residences.Finally,the "evaluation and grading" of hoisting construction safety risk was verified by the example,and the study found that the hoisting construction safety risk level of the project was a lower risk,the overall risk level was good,and the project risk level trend was still in lower risk.However,the risk level of human factors and management elements is medium risk in the first indicator,which is higher than the overall project risk level.Based on the evaluation results,we propose control measures and do double "prevention" work to avoid risks at the source.This paper provides a new method for risk evaluation in the hoisting construction phase of future prefabricated concrete structure high-rise residential projects and is of reference value for the safety management of similar prefabricated concrete structure high-rise residential projects.