KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Access type: UnknownAuthor: search.filters.author.Sugimoto, M.

Search Results

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    The boundary condition of a 3D continuum model for a quasi 2D plane strain condition
    (2021-06-01)
    Chaiyaput, Salisa Fern
    ;
    Sugimoto, M.
    The half-model has been used in the finite element analysis, based on the symmetric condition against the tunnel’s longitudinal, vertical plane, but this design concept cannot apply to a staggered lining. Therefore, the authors have proposed a multi-ring model to present the segmental lining behavior of a 3D continuum ground model in the case of staggered building, but the proposed 12-ring model shows the different axial force distributions in circumferential directions between the center of the model and the end of the model, especially in cases of soft soil. Accordingly, to make clear, the mechanism of the above difference and to establish the analysis condition of the proposed model for quasi 2D plane strain condition, this paper evaluates the influence of boundary condition on the transverse cross section at the end of the segmental lining on the segmental lining behavior, based on the analyzed axial force and bending moment in soft and stiff ground conditions using both the 2-ring model and a 12-ring model. As a result, it was confirmed that the proposed 2-ring model could simulate the segmental lining behavior under quasi 2D plane strain condition.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Evaluation method on ground movement using continuum ground model
    (2021-01-01)
    Sugimoto, M.
    ;
    Chen, J.
    ;
    Anh, P. T.
    ;
    Manabe, K.
    ;
    Lam, L. G.
    To analyze the ground movement and the influence of shield tunneling above tunnel structures, the continuum ground model with segmental lining is in use. The analysis region in the transverse section should confirm that the side boundaries do not give significant effects on the analysis results. On the other hand, the lower analysis region is selected based on the empirical value to fit the analysis result for the measured data in practice. The effects of tunnel excavation in the numerical analysis are classified into two parts: one is the unloading effect because of the removal of the soil weight at the tunnel section, and the other is the effect of stiffness reduction inside the tunnel. The former heaves the ground around the tunnel, of which the magnitude increases as the distance from the tunnel invert to the bottom of the analysis region increases. This influence increases as the ground stiffness decreases. This is because the numerical analysis is based on the stress–strain relationship and the displacement comes from the distance multiplying with strain in the case of the elastic model. The latter one causes the upper part of the ground around the tunnel to move toward the tunnel, which decreases the ground reaction. The analysis results include both effects. This study shows both effects on ground displacements separately, taking the lateral region size W and the lower region size d as parameters, and discusses the method to evaluate the analysis results.