Study Of Stratum Sensitivity And Structure Applicability Of Interchange Tunnel

With the implementation of "Urban Promotion Action Plan",urban construction land is becoming increasingly tense,but the number of urban population is increasing,coupled with the irresistible trend of car popularity in domestic metropolitan areas,road traffic congestion is becoming more and more serious,and urban traffic congestion has become a focus that needs to be solved urgently in today's society.At the same time,the "19th National Congress Report" pointed out that China must be built into a powerful country for transportation.Therefore,in the city,metro,rail and other traffic is constantly emerging,with the underground traffic up-crossing and down-crossing existing tunnels constantly appearing.At present,there are few studies on the interaction between interchange tunnels,and the existing studies mainly focus on specific projects,lacking systematic and universal research.According to the requirements of the Ministry of Communications and the preliminary assumption of the Chongqing Transportation Bureau on the "Outline for the Construction of the Demonstration Zone of Chongqing's Transportation Powerful Country",by 2035,the demonstration zone of Chongqing's Transportation Powerful Country will be built in an all-round way,and the transportation of Chongqing will basically realize modernization and reach the international advanced Therefore,based on the project of Chongqing Science and Technology Talents Training Plan(Leading Talents)"Research on Stratum Sensitivity and Structural Adaptability of Urban Underground Road",this paper systematically studies the construction mechanics of interchange tunnels with different buried depth,different surrounding rock grade,different tunnel spacing and different construction sequence by means of numerical analysis,model test and on-site monitoring research methods.For the influence relationship and degree of existing tunnels,more economical and effective reinforcement measures are put forward for the main environmental sensitive areas,and a set of structural adaptability system for the influence area of interchange tunnels is formed.The main research contents of this paper are as follows:(1)to consult the existing data,summarize the research results of the near-connection construction of existing interchange tunnels,judge and classify the simulated interchange conditions,and comb out the calculation and test work.(2)On the basis of summarizing the past experience and achievements in engineering investigation,according to the characteristics of urban underground roads,the calculation models of overpass tunnel proximity with different burial depth,different surrounding rock grade,different proximity distance and different construction sequence are established,and the numerical calculation is carried out according to the combination of working conditions.(3)Based on the calculation results,the factors affecting the intersection of underground overpass tunnels are studied,and the function expressions of stress and tunnel burial depth,surrounding rock level,and proximity distance are derived using the principle of spatial dispersion fitting and tunnel construction mechanics.The influence spacing of different buried depth,different surrounding rock level and different construction sequence was studied.(4)The sensitivity zoning and zoning index of underground engineering adjacent to different interchange tunnels are studied.The analytical solution of sensitivity analysis of interchange tunnels is deduced by limit equilibrium method.The sensitivity of different buried depth,different surrounding rock grade and different tunnel net distance is studied by single factor method,and the corresponding sensitivity index is put forward.(5)Through indoor model test,the stress distribution and influence of new tunnel construction on existing tunnel lining under different tunnel clearance are studied,the failure modes of existing tunnel are analyzed,and the numerical results are verified;(6)According to the existing projects and the above research results,according to the control indicators,the monitoring and measurement plan of the interchange tunnel is studied,and the impact of the construction of a new tunnel on the existing tunnel is monitored and analyzed on the spot.The rationality of the control indicators and the correctness of the analytical formula are verified.(7)According to the sensitivity zoning method of interchange tunnels developed in this paper,the adaptability analysis of commonly used structures is carried out,and the structural adaptability Countermeasures of different sensitive areas are put forward.At the same time,the special construction methods and adaptable structures of strong sensitive areas are put forward,which provide technical basis for the design and construction of Interchange tunnels and improve and promote the development of interchange tunnel construction technology.