Yazar "Yuksel, Yusuf Ziya" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Dynamic Responses of Layered Viscoelastic Half-Medium with Twin Tunnel Under Harmonic Load
    (Springer Heidelberg, 2024) Yuksel, Yusuf Ziya; Akbas, Seref Doguscan
    Purpose This paper presents dynamic analysis of layered viscoelastic half medium which includes twin rectangular tunnel under harmonic load. Viscoelastic half medium is considered and modelled with using Kelvin-Voigt viscoelastic model and two dimensional (2-D) continua.Methods The considered problem is solved by using finite element method. The energy expressions of the system are obtained and equation of motion are obtained by using Lagrange procedure. Infinite region far from twin tunnel is modelled by using infinite elements with 8 nodes and finite region is modelled by using 16 nodes finite elements. The dynamic equations for finite and infinite elements are solved by using Newmark-Beta method in time domain. Finite and infinite element models with different layers and twin tunnel are generated and numerical solutions are obtained by using an algorithm by authors.Results In order to achieve verify the used models and methods, some special results are obtained and compared with results from a finite element software. In numerical studies, effects of location of twin tunnel on dynamical responses of the system under harmonic load are obtained in figures and discussed in detail. Dynamic tunnel-medium interaction is discussed in the obtained results.Conclusions The numerical results show that tunnel location plays important role on the dynamic responses of half medium and dynamic responses change significantly with tunnel-medium interaction. In field near to the tunnel, the dynamic responses are more affected. Important practical implication is that computational cost for this kind of problems could be reduced, more realistic results could be obtained and all boundary conditions could be considered by used model with infinite elements. The used model and method are very useful and practical for dynamic analysis of tunnel structures.
  • Küçük Resim Yok
    Öğe
    Nonlinear Static and Dynamic Analysis of Semi-Infinite Porous Medium with Twin Tunnel
    (World Scientific Publ Co Pte Ltd, 2024) Yuksel, Yusuf Ziya; Akbas, Seref Doguscan
    Tunnel-medium interaction problems are one of the important problems in engineering. Because it has a high risk in terms of reliability, tunnel structures should be modeled in detail. The modeling of tunnel structures under static and dynamical loads is a difficult problem in engineering because of consists of a lot of conditions and effects, such as heterogeneous medium, soil layers, porosity, soil-structure interaction, groundwater, earthquake, etc. In this paper, aims to investigate the tunnel-medium interaction problems for nonlinear static and dynamic analyses. This study includes nonlinear static and dynamic analyses for layered porous semi-infinite viscoelastic medium with twin tunnels. The constitutive property of each layer of medium is considered in bilinear stress-strain relation with uniform porosity and Kelvin-Voigt viscoelastic property. The considered study is solved via the finite element method within the two-dimensional (2D) model. Layered medium is modeled as finite and infinite elements. In the solution process, the incremental force method is implemented and, for each load step, finite element equations are solved according to the bilinear stress-strain relation. In nonlinear dynamic analysis, the dynamic loads are divided by a certain finite number and applied incrementally depending on the time-dependent load function. At each load step, the final displacement, velocity and acceleration of that load step, obtained as a result of applying the Newmark beta method procedure, are assigned as the starting value of the next load step according to the bilinear stress-strain relation. Influences of porosity and position of tunnels on the nonlinear static and dynamic deflections of the system are investigated. Also, differences between linear and nonlinear responses are compared and discussed.