Research on the Safety of Tunnel Initial Support Structures Based on Nonlinear Constitutive Models in ABAQUS
In tunnel engineering,it is crucial to accurately assess the structural safety of the initial support in its dynamic design stage.Taking the primary support structure of a Grade V surrounding rock structure without invert support of a highway tunnel in Yunnan as an example,the three-dimensional refinement model of the primary support structure was constructed by ABAQUS software,and the analysis was carried out by using the nonlinear constitutive relationship of concrete in order to assess the ultimate displacement,ultimate bearing capacity of the initial support and the potential instability state of the tunnel.The results showed that:the initial support structure was mainly subjected to tensile force on the inner side of the arch and compression on the outer side,compression on the inner side of the arch shoulder and tensile force on the outer side,as well as tensile force on the inner side of the arch and compression on the outer side of the arch foot;the peripheral rock initial support shows the deformation characteristics of the arch sinking and the outward expansion of arch shoulder on both sides,and the displacement of the sidewalls has a relatively small value of convergence;the use of nonlinear constitutive relationship can effectively simulate the process of the structure section in the process of the formation of plastic hinges,the reduction of stiffness and the redistribution of internal forces.The use of nonlinear constitutive can effectively simulate the process of plastic hinge formation,stiffness reduction and internal force redistribution.Therefore,it is recommended to use the nonlinear constitutive model to evaluate the safety of the initial support structure.The study is of great theoretical significance and practical value for improving the design level and ensuring the safety of tunnelling projects.
highway tunnelinitial supportnonlinear constitutive modelsthree-dimensional refined modelingsafety research
NETL
NSTL
万方数据
