Research On Construction Risk Assessment Of Deep Foundation Pit Based On Combination Weighting And Set Pair Analysis

In recent years,with the sustained and rapid development of urbanization in China,the urban development space is increasingly limited,so the number of deep foundation pit projects is increasing,and the volume of projects is increasing.Foundation pit engineering is an important part of building engineering,which has the characteristics of large investment,complex technology,and complex construction environment,so construction accidents of foundation pit engineering projects frequently occur in China.Accurately evaluating the construction risk of deep foundation pit projects is the basis and key to scientifically formulate risk response measures.Therefore,the following research work was completed.(1)The related research results of deep foundation pit construction risk management were investigated to analyze the shortcomings of related research.The definition and characteristics of deep foundation pit construction risk were refined,and the general process of deep foundation pit construction risk management was summarized.The calculation principles and applicability in this study of common risk identification methods,weight calculation methods,and risk evaluation methods were introduced and discussed.(2)A set pair evaluation model for the construction risk of deep foundation pit engineering was constructed in this paper.Firstly,with the help of WBS-RBS matrix and the questionnaire survey method,an index system of deep foundation pit construction risk evaluation was constructed to effectively deal with the complexity of deep foundation pit construction risk.Then,the projection pursuit model optimized by particle swarm algorithm was used to mine the structural features of evaluation data to obtain objective weight,the G1 algorithm was used to process the information of experts’ index importance judgments to obtain subjective weight,and the combined weights were calculated by the method of maximum grade difference.Finally,a set pair evaluation model of deep foundation pit construction risk based on five-element connection number was constructed,and the partial derivatives of five-element connection number was analyzed by the set pair potential,thus realizing the static evaluation and dynamic evolution of deep foundation pit construction risk.In addition,the realization method and process of the evaluation model was gave in detail.(3)The deep foundation pit project of Qi’an House in Huanggang City was selected for empirical analysis.The results showed that the construction risk level of this project was acceptable and its risk was declining.The evaluation results were basically consistent with the engineering practice,which proved that the research method proposed in this paper was scientific and effective.The biggest first-level risk factor affecting the project was the equipment risk,and the biggest second-level risk factor was the elasticity of material supply chain.Project managers should focus on the elasticity management of equipment and construction materials supply chain.Compared with classical methods(the analytic hierarchy process,the entropy weight method,other classical combination weight calculation methods,the fuzzy comprehensive evaluation,and the grey clustering method),the research method proposed in this paper was advanced.In addition,targeted risk management measures were given for deep foundation pit engineering.Based on the modern risk management theory,the Particle Swarm Optimization,the Projection Pursuit model,the G1 algorithm,the differential maximization method,and the Set Pair Analysis,and fully combining with the construction characteristics and management practice of deep foundation pit in China,the risk evaluation index system and set pair evaluation model of deep foundation pit construction were constructed,and the deep foundation pit project in Qi ’anfu,Huanggang was taken as an example to conduct a detailed empirical study.The related research results are helpful to improve the theoretical and empirical research of deep foundation pit construction project management in China.