Study On Safety Evaluation Of Subway Tunnel Construction Period Based On Rough Set And Case-based Reasoning

Our country is in a period of rapid development of subway construction.If we want the subway construction to develop faster and better,we must take safety as the top priority.Therefore,we must have a sound metro construction safety evaluation system.At present,there is no systematic safety evaluation system for metro tunnel construction in our country.The existing safety evaluation system is not comprehensive enough.Because of many influencing factors,it subjectively influences the subjective influence of appraisers.Therefore,it is urgent and urgent to present a comprehensive and objective security evaluation system and evaluation method.In this paper,based on case-based reasoning,CBR(Case-based Reasoning)system of subway tunnel construction safety evaluation is proposed.The system is in line with the human thinking process of solving problems and can use the past experience to solve the new problem,that is,using the previous safety evaluation cases to help the safety evaluation of new projects.In the process of constructing the system,the case retrieval algorithm is the key link.This paper focuses on the research of this loop.By using the attribute reduction features of the rough set,the security evaluation index system is simplified and the workload of case retrieval is reduced.Combined with the principle of attribute importance of rough set theory,the weight coefficient of each index is calculated to facilitate the calculation of case similarity in case retrieval,so as to realize the case retrieval process.Based on the survey of 10 experts and workers in the actual project of Shenyang Metro Line 4,this paper obtained the score of the safety evaluation index system during the construction period of the shield tunneling subway tunnel.Combined with the rough set theory,the safety of the shield method The evaluation index system is reduced and the weight coefficient of the reduced index is obtained.It provided a basis for the establishment of CBR system case library.At the same time using the reduction of the index system to evaluate the project,the result is safe.In the process of this paper,a great deal of reference is made to the relevant current laws and regulations in our country.A large number of documents and references were consulted to investigate the 61 construction safety accidents in subway tunnels in recent years and the types of accidents were statistically analyzed.According to the analysis of the subway tunnel construction safety factors,respectively,the three methods commonly used in subway tunnel construction safety evaluation index system.Then,by using the combination of rough set theory and case reasoning,this paper studies the safety assessment system during the construction of subway tunnels,including the description of key technologies and the case retrieval in the establishment of CBR system.In particular,in the course of case retrieval,the index system is reduced according to the attribute reduction of rough set theory,and the weight of each index is calculated by rough set attribute importance principle,which reduces the case retrieval process The workload of CBR system to improve the overall efficiency.