Influence of Surrounding Rock Creep on Invert Heave of High-speed Railway Tunnel in Mudstone
Research purposes:Aiming at the disease of the invert heave during the construction of the high-speed railway tunnels in the mudstone area,the method of parameter inversion and numerical simulation were adopted,the influence of the surrounding rock creep on the invert heave was comprehensively analyzed,and the engineering measures of bolt support and invert reinforcement were used to control the invert heave.Research conclusions:(1)The Burgers model can better describe the obvious decay creep and stable creep characteristics of mudstone.(2)With the increase of time,the surrounding rock was continuously deformed into the tunnel.The tunnel crown settlement,horizontal convergence and invert heave have been increasing,which experienced three stages:instantaneous deformation stage,attenuation creep stage and steady creep stage.(3)The internal force of the invert structure also increases with the passage of creep time.After a certain period of creep,the tensile stress of the invert filling center will exceed the tensile strength of the concrete,causing the invert filling to crack along the center position.(4)The optimal length of the bolt support is 5 m,and the optimal spacing is 0.9~1.2 m.On this basis,the deformation of the invert heave was further suppressed by strengthening the invert.It is suggested that the support strength of the invert should be C30~C40.(5)The research results can provide suggestions and references for the construction and construction of similar projects.
tunnel in mudstoneinvert heaveparameter inversionnumerical simulationinvert heave control