Research On Calculation Model And Structure Reliability In Railway Composite Lining Of Tunnels

In this paper, the performance function suitable for reinforced concrete tunnellining structures is developed, through the derivation of the limit state equation ofeccentrically compressed reinforced concrete members. By the sampling accordingto the basic principle of Monte Carlo method, statistical characteristics of load effectfor internal lining structures is investigated based on load-structure model. Thereliability of reinforced concrete tunnel lining structureis analyzed with the basicprinciple of JC method, A new calculation method of the reliability index for liningstructures is proposed, which provides a referencefor the modification of the designspecifications of railway tunnels according to reliability theory.Composite lining is a bearing system composed by initial support and secondarylining, But, both in the composite lining role currently still exist different perceptions.In view of the existing problems, the calculation model of the composite lining is setup for Numerical simulation and theoretical analysis by ANSYS.The basic principle and advantages and disadvantages of the currentload-structure model and formation Structure model are elaborated. In the foundation,the load-structure model based on formation together method is put forward andanalyzed. On that basis, the design method which main bearing form is initial supportis calculated，discussing the influence of boundary size on the calculation results,producing the safety factor of the initial support and secondary lining under differentrock level.On the basis of the new limit state equation, analyzing the reliability ofcomposite lining and the influence of each variable on the result, to research theapplicability of the new equation; meanwhile, using the interaction model incombination with the new limit state equation of composite lining structure for thetrial, analyzing the reliability of the results, and comparing the sensitivity of thevariables.