Study On Geological Adaptability Of Construction Parameters Of Double-shield TBM Based On Shenzhen Metro Tunnel

With the rapid development of urban rail transit,TBM construction technology has been widely used in rock stratum with its advantages of high safety performance and fast driving speed.However,at present,the setting of TBM tunnel driving parameters still depends on construction experience combined with on-site stratum feedback,lacking systematic research.As TBM construction technology will be more and more widely used,it is necessary to analyze the formation adaptability of TBM parameters in the driving period.In this paper,the double-shield TBM is taken as the research object,and the contact theory between the hob and the rock mass is taken as the starting point.The response characteristics of the rock mass under the penetration of the disc hob are analyzed by the method of theoretical analysis and numerical simulation,and the applicability of different prediction formulas of rock breaking force in the hard rock environment is discussed.Based on the study of rock breaking mechanics mechanism of hob,the key parameters affecting TBM driving efficiency are selected.The practical operation parameters in the construction process of TBM method of Shenzhen Rail Transit Line 8phase I project are analyzed,and the mechanical calculation model of key driving parameters is established,so as to explore the interaction between the properties of surrounding rock and driving parameters.Secondly,according to the statistical results of TBM driving parameters along the Wusha section,the parameter distribution characteristics of the longitudinal driving force,cutter head torque,rotation speed,penetration and driving speed along the tunnel are statistically analyzed,and the mapping law between driving parameters is quantitatively analyzed.At the same time,the distribution parameters of tunneling parameters in the broken zone section are proposed for setting the tunneling parameters when the TBM passes through the fault zone.Finally,in order to get the response characteristics of rock mass under different working conditions,ABAQUS software is used to discuss the influence of different excavation parameters setting on rock breaking process of hob by changing the parameter setting,and summarize the excavation efficiency of TBM under different excavation parameters setting and the regularity difference of determining parameters under different surrounding rock conditions.On the basis of the mutual confirmation of the above theoretical calculation,measured parameter law and numerical simulation results,the geological adaptability of TBM construction parameters of double shield in metro tunnel engineering is studied and some useful conclusions are obtained.It is expected to provide some technical support for the development of TBM tunnel construction.