Construction Risk Assessment Of Semi-submersible Lifting And Dismantling Platform

With the continuous expansion of the international dismantling market,the demand for semi-submersible lifting and dismantling platform,a highly competitive special ship,is increasing.In order to improve the construction efficiency,reduce the construction cost and ensure the high quality completion of the platform,it is necessary to carry out the risk assessment of the platform construction process.Therefore,it is of great significance to carry out the research on the construction risk assessment of semi-submersible lifting and dismantling platform.The purpose of this study is to propose an overall risk assessment model.Taking a semi-submersible lifting and dismantling platform construction project as the object,the platform construction risk assessment research is carried out,which mainly involves the following work :(1)The structural characteristics and main dimensions of the platform are briefly introduced,and it is divided according to the system and segmentation.Secondly,the risk management system including construction quality management risk,production management risk and safety management risk is established,and the risk identification of the platform is carried out by using case analysis method,safety operation analysis(JSA)method and design and process audit method,and the risk list is obtained by combining expert experience.(2)The risk assessment model is the integration of triangular fuzzy number,interval-valued Pythagorean fuzzy set(IVPFS),TOPSIS and GRA.The importance weight of experts is obtained by triangular fuzzy number,and a weighting method combining subjective weight and objective weight based on similarity is provided.By summarizing the literature,the basic risk parameters required for platform construction are determined.By combining the TOPSIS-GRA risk assessment method in the interval-valued Pythagorean fuzzy environment,the final ranking of the identified risks is obtained,and the key risk factors are obtained.Then,the importance weight of experts is obtained by triangular fuzzy number,and a weighting method combining subjective weight and objective weight based on similarity is provided to avoid the subjectivity of decision makers.By summarizing the literature,the basic risk parameters required for platform construction are determined.By combining the TOPSIS-GRA risk assessment method in the interval-valued Pythagorean fuzzy environment,the final ranking of identified risks is obtained.(3)The robustness and stability of the proposed method are verified by two forms of adjustment,including adjusting the parameter size with a step size of 0.1 and changing the expert weight.Through rational analysis and comparative study with fuzzy matrix evaluation and grey correlation evaluation method,the reliability and practicability of the evaluation method are verified.According to the evaluation results of construction quality management risk,production management risk and safety management risk,the corresponding preventive measures are put forward respectively.Through the application of various risk identification methods,this thesis fully identifies the risks in the platform construction process;the subjective and objective weighting method can avoid the subjectivity of decision makers;the proposed model can help experts conduct risk assessment in a fuzzy environment with fuzzy and subjective language processing,overcoming the limitations of common quantitative and qualitative estimates.This study has certain practical significance for the risk management of semi-submersible lifting and dismantling platform,and can provide some reference value for the research in the field of platform construction risk assessment.