Structural Safety Analysis Of Operating Heavy-haul Railway Tunnel Under Disease Condition

Various kinds of disease problems are common in the existing heavy-haul railway tunnel.With the increasing demand for materials,the axle load and grouping of heavy-haul railway increase greatly,which further aggravates the existing disease problems and reduces the safety of the structure Based on the on-site inspection data of Shuohuang railway tunnel diseases,the influence of lining structure diseases on tunnel structure safety under two working conditions of surrounding rock pressure and train load is analyzed by numerical simulation,which provides reference for safety analysis and maintenance of lining structure under the working conditions of heavy load railway tunnel diseases.(1)In the Shuohuang overloaded railway tunnel disease testing data for reference,the statistical analysis of tunnel disease in recent years,get the Shuohuang railroad tunnel of the main disease types,based on the thickness of tunnel lining Behind the lining empty Lining cracking defect defect situation to carry on the summary,provide a reference for subsequent disease lining safety analysis values.(2)Establish the stratum-structure model of insufficient thickness tunnel lining,calculated the stress of surrounding rock and tunnel under two kinds of working condition of train loads on exist when lining thickness defect of the structure of the internal force and safety factor,get different lining thickness on the structural internal force and the influence of safety factor,and gives the structure internal force and safety coefficient changing with the different thickness of the lining,and compares the two kinds of working conditions of surrounding rock pressure and train load lining thickness deficiencies The necessity of the train load factor in the analysis of the structural safety caused by insufficient lining thickness is obtained.(3)By calculating the internal force and safety factor of the stratum-structure model with different cavity range,the change rule of the internal force and safety factor of the tunnel structure with different cavity range is given.Through numerical simulation analysis,it is obtained that: when the cavity is less than 30 With the increase of the cavity range,the lining structure is subjected to pressure into tension,and the safety factor decreases greatly.By comparing the safety factor of the structure under the two working conditions of surrounding rock pressure and train load,it is concluded that the presence of train load will reduce the safety of the structure behind the lining with the cavity.(4)Based on linear elastic fracture mechanics theory,cracking tunnel lining was established based on the finite element model,the calculation of the surrounding rock pressure and train load two different positions under the condition of different crack depth of the crack tip stress intensity factor and the stability coefficient,get crack tip stability coefficient changing with the crack depth,and presents two kinds of working conditions of different surrounding rock pressure and train load position Stability of fracture tip at different fracture depths.