Study On The Adaptability Of Construction Method Of Large-span Highway Tunnel With Soft Surrounding Rock

With the further development of tunnel and underground engineering,the geological conditions of tunnel and underground engineering are becoming more and more complex.This requires appropriate construction technology and high construction quality.Therefore,it is a significant analysis of construction methods.In this paper,theoretical analysis,numerical simulation and field measurement are used.This paper introduces three construction methods of the left line ZK34 + 600 ～ ZK34 + 750 section of Tong zi tunnel,namely,the double side heading method,the CD method and the three parts seven steps method.This paper analyzes the adaptability of three construction methods.The main research contents and achievements of this paper include:(1)Through literature research,the paper summarizes the development status,construction methods and research methods of large-span soft highway tunnels at home and abroad.This is the basis of studying the adaptability of construction methods.(2)This paper combines the engineering situation and geological conditions of Tong zi tunnel.Then the paper discusses the construction process and technological process of double side heading method,CD method and the three parts seven steps method used in the left line ZK34 + 600 ～ ZK34 + 750 section of Tong zi tunnel.This paper summarizes the advantages and disadvantages of the three parts seven steps method.The paper establishes the evaluation system of these three methods.This paper uses this evaluation system to evaluate the adaptability of the three methods.(3)In this paper,Midas GTS / NX software is used to simulate the three methods.This paper analyzes and summarizes the change rules of displacement field and stress field of these three methods.According to the results of numerical simulation,the three methods are compared.(4)This paper uses analytic hierarchy process to establish mathematical model.The optimal construction scheme is obtained by calculation.The paper evaluates the adaptability of these three methods.This provides a basis for the optimization of construction methods.(5)This paper summarizes the field monitoring and measurement work.This paper analyzes the monitoring data of the corresponding section of the numerical simulation.In this paper,the results of numerical simulation are verified by field data.According to the monitoring results,the paper evaluates the construction technology on site.The paper also developed three steps and seven steps of construction safety control measures.