Study On Surrounding Rock Deformation Mechanism And Mechanical Characteristics Of Supporting Structures Of Qingdao Metro Tunnel

With the rapid development of economy,the construction of buildings on the ground is becoming more and more intensive,and the population is rising rapidly.It has further caused traffic congestion and shortage of resources.Qingdao,as a modern metropolis,improving the efficiency of urban life is the premise of urban development.As for this,improving the utilization rate of underground space is an effective way to alleviate congestion.The construction of Qingdao Metro Tunnel Project is put on the agenda.Based on the first phase of Qingdao Metro Line 2 project,the stability of tunnel surrounding rock is analyzed by FLAC3D software,and the deformation analysis of surrounding rock under various supporting forms is simulated.The following is the main work of this paper:(1)Firstly,this paper studies the present situation of stability analysis of underground surrounding rock and the problems existing in the analysis method section of surrounding rock at present,introduces the methods of tunnel excavation correlation analysis and rock mechanics parameter analysis,emphatically introduces the numerical simulation method,and introduces the practical application mode and implementation principle of various analysis methods in rock engineering.In underground tunnel engineering,we should choose reasonable analysis methods according to the specific engineering background and geological conditions and other factors.(2)In this paper,the theoretical formulas of the influence of circular section and horseshoe section on the deformation of tunnel surrounding rocks are summarized according to the influence of different section forms of tunnel entrance on the deformation of tunnel surrounding rock.(3)The influence of tunnel excavation on surrounding rock under four support modes is simulated.The vertical displacement,horizontal displacement,vertical stress,horizontal stress,displacement vector and plastic zone of surrounding rock under four support modes are analyzed in detail.By comparing the data of bolt support force,vertical stress,vertical deformation,horizontal deformation and plastic failure of surrounding rock under four supporting modes,the more suitable supporting conditions for judging circular tunnel and horseshoe tunnel are put forward.In this paper,the deformation of surrounding rock under four supporting conditions is analyzed by using simulation software,and the deformation mechanism and law of lateral and vertical separated surrounding rock are obtained.These research results can be used for reference in the design and construction of practical projects.