High-speed Railway Tunnel Structure Of Two-dimensional Dynamic Analysis Program Developed

Train vibration is a long-term and reciprocal load. It's one of the substantial clauses to cause railway tunnel diseases in our conntry in the last few years. With the train running speed acceleration, vibration wave transfered to tunnel structures by orbit system strengthen accordingly. Especially, when plate ballastless rail is used as the orbit structural style, the vibro-impact intensity transfered to tunnel structures become much larger than usual. Because the rigidity of plate rail is very large. So higher dynamic stability for tunnel structures is required. But now, universal business software lacks pertinency on high-speed railway tunnel structure dynmic computation. In this paper, tunnel structure dynamic response analysis program has been developed, supported by the science and technique research development plan of Ministry of Railways "tunnel structure dynamics down high-speed tran" and state physical science fund item "rich water crack gap rock mass dynamics damage coupled wave theory and it's application foundation research". The main works are discribed as follow:(1) The finite element model computing dynamic response of the tunnel structures under high-speed train dynamic load is established.(2) The plane dynamic calculation program TD2D is developed by Fortran language:Four node and eight node isoparametric elements are adopted in the program, enhancing the calculation accuracy and adaptation of the bound complicated shape; There are no restriction on number of element and node, The requied memory is dynamically allocated according to the scale of the problem; Static loads like concentrated load, boundary distributed force, self-weight, temperature load and dynamic loads including different kinds of shock and vibration loads, acceleration of eardthquake can be simulated in this model; Dual non-linearity of material and geometry can be simulated.(3) On the basis of the specialities of geotechnical engineering numerical analysis, the Newmark time integration method is adopted to dynamic equilibrium equation. Newton-Raphson iterative method is used to solve the nonlinear equations, can effectively solve nonlinear problems of structure dynamic analysis.(4) User interfaces are designed based on the mixed language programming of Fortran and Visual C#.NET. It makes computation model establishment visual and simple and effectly, to prevent the error occurred and convenient to use the program.(5) Both theoretical analysis and software contrast figure ways are used to test the accuracy and validity of the program. In the same time, the program is used to compute the dynamic response of one railway singlet tunnel under train upshaft load.