| With the development of economic,cultural,tourism and the acceleration of urbanization in China,the country and the people have higher and higher demand for travel of traffic and transportation,the cross-ocean tunnel and over-river tunnel that meet the development needs of times have been widely used.Many large tunnel projects built or under construction,such as the Chiongzhou Strait sea-crossing engineering,nanchang red valley tunnel,Hong Kong-Zhuhai-Macao immersed tube tunnel,are in a complicated Marine environment,and our country is in the circum-pacific seismic belt,underwater engineering risks by seismic action,in the event of disasters,not only can major accidents occur,but it can also cause huge losses to the economy of the surrounding area,so the study of its seismic performance must be taken seriously.In this paper,the homogeneous seabed soil immersed tube tunnel in the longitudinal response under seismic action was studied,based on the wave theory considering fluidstructure coupling effects of seabed soil and seawater,based on the three-dimensional finite element model was established,the analysis of the tunnel outlet structure of joint stiffness,longitudinal slope degree and depth of the influence of the dynamic response of immersed tube tunnel structure,the main research contents are as follows:(1)This paper introduces the research background,earthquake damage and dynamic response analysis methods of underground structures,and the current dynamic analysis results of immersed tunnels.(2)Based on the wave equation of one-dimensional elastic wave,a three-dimensional viscoelastic artificial boundary was established.Combined with the finite element analysis method,the calculation method of the equivalent load of the artificial boundary node of threedimensional ground motion at normal incidence was deduced by using the displacement and velocity obtained from the free-wave location.Through compiling Matlab program combinewith finite element software to realize the three-dimensional numerical simulation of seismic wave normal incidence.Numerical examples verify the accuracy.(3)The dynamic finite element discretization equation for the inviscid compressible fluid was derived using the hydrodynamic equation.Based on this,the boundary conditions at the interface between fluid and solid were deduced and combined with ADINA.(4)Based on three-dimensional finite element model of immersed tube tunnel,analyzes the P wave vertical incidence,the seismic response of immersed tube tunnel,discusses the joint stiffness and longitudinal slope degree effect on the seismic response of the tunnel.(5)Established a homogeneous seabed soil tunnel-water model,considering the porous seabed soil,combined with the fluid-structure interaction theory,analysis the influence of water depth on the earthquake response of the tunnel,it is concluded that water depth for the response law of the earthquake response of the tunnel. |
