• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.3
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• pp.21-30
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• 1986

A method for elasto-plastic analysis of grillages is proposed in this investigation. An effort to construct the stiffness matrix of the member with bending and torsional springs attached at both ends is made in this work to make each member of grillage behave elasto-plastically. A related computer program EPAG for elasto-plastic analysis of grillages is also developed. The characters of this program in comparison with existing methods are as fellows; grillage with arbitrary geometry can be analysed, collapse load is applied in one step instead of incremental procedure, unloading can be considered, and analysis results such as applied loads, member end forces and joint displacements are also obtained when individual plastic hinge is formed. For verification of performanse of the EPAG, illustrating examples are solved and compared with the results of specified literlatures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.1
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• pp.105-117
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• 1994

A finite element procedure which can trace plastic collapse behavior of plane frame structures under small and large deformation is presented. The member is assumed to be prismatic and straight, and has the rectangular or I cross section. For the elasto-plastic analysis, the concept of plastic hinge is introduced and the incremental displacement method is applied. The limit state condition of the plastic hinge is considered under the combined condition of a bending moment and an axial force. Numerical examples are presented in order to demonstrate the validity and efficiency of the proposed procedure.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.2
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• pp.107-118
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• 2021

Due to the acceleration of road construction, the number and extension of tunnels are increasing every year. A lot of research has been done on the collapse of tunnels, but research on the invert heaving is insufficient. Therefore, in this study, a sensitivity analysis was performed using a geotechnical general-purpose program to analyze the effect of the invert curvature of a tunnel excavated on the soft ground. As a result, it was quantitatively confirmed that the stability of a tunnel was increased as the curvature of the tunnel invert was increased so that the safety factor was calculated to be large regardless of the ground conditions and the thickness of the support. In addition, it was confirmed that the stability of the tunnel was increased by reducing the convergence of the tunnel and the maximum bending stress supported by shotcrete. Therefore, when a tunnel is excavated on soft ground, it is believed that applying a curvature to the invert will increase the stability of the tunnel.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.4
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• pp.369-376
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• 2003

In this paper, a nonlinear structural analysis for the composite structure composed of the spent nuclear fuel disposal canister and the 50㎝ thick bentonite buffer is carried out to predict the collapse of the canister while the horizontal symmetric sudden rock movement of 10㎝ is applied on the composite structure. This sudden rock movement is anticipated by the earthquake etc. at a deep underground. Elastoplastic material model is adopted. Drucket-Prager yield criterion is used for the material yield prediction of the bentonite buffer and von-Mises yield criterion is used for the material yield prediction of the canister(cast iron, copper). Analysis results show that even though very large deformations occur beyond the yield point in the bentonite buffet, the canister structure still endures elastic small strains and stresses below the yield strength. Hence, the 50㎝ thick bentonite buffet can protect the canister safely against the 10㎝ sudden rock movement by earthquake etc.. Analysis results also show that bending deformations occur in the canister structure due to the shear deformation of the bentonite buffer.

• Journal of the Korean Geosynthetics Society
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• v.22 no.2
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• pp.23-33
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• 2023

Currently, there are cases in Korea where economic damage has occurred due to the ambiguity instrument installation and operation standards in the construction of temporary earth retaining wall, failing to prevent collapse of temporary earth retaining wall at the construction site in advance. Therefore, in this study, a numerical analysis was conducted to find the appropriate installation location of the inclinometer and strain gauge among the installed instruments shown in the design drawing of the temporary earth retaining wall. As a results, It was found that the installation position of the underground inclinometer is the corner of the retaining wall in the case of plane-deformation analysis, and the most displacement occurs in the center of the excavation surface in the case of 3D analysis. When the stress and moment are comprehensively analyzed, the corner is judged to be a vulnerable point. In the case of the strain gauge, In plane-deformation analysis and 3D analysis, the maximum bending stress occurred at the wale connection where the end of the strut and the counter strut are in contact. At this point, it is analyzed that it is necessary to focus on installing and managing the connection to prevent accidents from being vulnerable.