| In this paper, Xie Jialiang tunnel, as a part of the Taoba highway LJ15contract segment,is described as engineering background.,ANSYS,the finite element analysis software, is usedto get a reasonable solution,considering the safety of. construction and secondary lining.Mainly from the tunnel excavation method,excavation footage and step length,the research isfinished to provide theoretical guidance for the tunnel excavation.Considering loads release,Iuse the safety factor to study the force characteristics of secondary lining and analyze itssecurity. Finally, the security of tunnel construction and secondary lining can be determinedby analyzing monitoring measurement data and numerical simulation.During tunnel excavation, this paper presents results of the wall rock displacement,equivalent stress, and SMF. SMF(Strength Mobilization Factor) is derived from theMohr-Coulomb, based on the critical failure of rock. When SMF=1, that is,rock mass gets tolimit state and will enter the plastic stage.By the numerical simulation for Xie Jialiang tunnel construction and secondary lining,this paper arrives at the following conclusions:(1) Similar results can be got from the the numerical simulation between construction oftwo-step and three-step, considering vault settlement, the displacement and stress of rock, andSMF. V surrounding rock section of Xie Jialiang tunnel uses two-step method.(2) Considering different excavation footage,this paper analyses tunnel vault settlement,the displacement and stress of rock, and SMF. V surrounding rock section of Xie Jialiangtunnel uses2.5m as excavation footage.(3) Considering different step length, this paper also analyses tunnel vault settlement, thedisplacement and stress of rock, and SMF. And, V surrounding rock section of Xie Jialiangtunnel uses5m as step length.(4)Using ANSYS for the2D numerical simulation of secondary lining, this paperextracts the axial force,bending moment, and a safety factor to determine the safety from theforce perspective. |
PDF Full Text Request