• Journal of Korean Society of Steel Construction
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• v.28 no.1
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• pp.35-42
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• 2016

This paper presents the structural analysis of two-span structures constructed by incremental launching method to traverse the existing facilities. The structure with a relatively short launching span can not be secure the structural stability caused by excessive deflection and overturning prior to reaching the maximum strength, because the length of the other span is different or the rear structure is not continuous. In order to estimate the stability of the construction stages of deflection and the overturning, the structural analysis was carried out. The parameters of the analysis is launching span ratio of the launching nose and the upper structure, weight ratio and so on. From the analysis result, the effects of parameters were investigated and a deflection formula of the launching nose and the condition of the overturning of structure were proposed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.373-374
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• 2006

This study is carried out to analyze the stability of a container crane in according to the change of a wind direction and a machinery house location when a wind load of a wind velocity, 75m/s was applied on the state stowing a container crane by a heavy wind. A design wind load applied to this study was calculated in observance of 'Load Criteria of Building Structure'. And we analyzed the reactions of each supporting points according to appling a wind direction to an interval of $10^{\circ}\;in\;0^{\circ}{\sim}180^{\circ}$ and the structure stability of a container crane according to changing a machinery house. location occupying 15% of a container crane weight. From a results of this study, we presented a design criteria of an overturning disturbance equipment, tie-down.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.371-372
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• 2006

This study was carried out to analyze the effect of wind load on the structural stability of a container crane according to the change of the boom shape using wind tunnel test and provide a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load 75m/s wind velocity is applied in a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary layer wind tunnel with $11.52m^2$ cross-section area. Each directional drag and overturning moment coefficients of a container crane according to the change of the boom shape were investigated.

• Journal of Biosystems Engineering
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• v.32 no.2 s.121
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• pp.69-76
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• 2007

This study was conducted to evaluate the sideways overturning stability of side loaded mini-forwarder. The model of a prototype was developed using a 3D CAD modeler and the performance was experimentally validated. The prototype model was run on the multibody dynamic analysis program, RecurDyn 6.0, to simulate motions when the model traversed over a circular bump on a inclined ground surface. The simulation was performed at a constant forward speed of 1.85 km/h under the loaded and unloaded conditions. The forward direction was also controlled to vary from 0 to 360 degrees with an increment of 10 degrees. Results of the simulation showed safe regions in which the mini forwarder could travel safely in terms of direction and slope of the ground. Even when the mini-forwarder was loaded by 20 logs of 3.6 m long and 12 cm diameter, it traveled safely within the ground slopes of 1 to 45 degrees by directions.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.106-113
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• 2009

In this study, stability of the new gabion system with vegetation base materials was analysed. New gabion system with vegetation base materials is a new approach which has been developed to achieve lope stabilization and revegetation of forest road cut-slope by making the best use of advantages of gabion systems with vegetation base materials. Results from stability analysis are as follows. For the soil density, the angle of internal friction and unit weight of the rock fill was assumed to be $1.90g/cm^3$, $30^{\circ}$ and $2.30t/m^3$, respectively, the slope stability analysis showed that the new gabion system couldn't require any poles to fix it up, and could keep stable during both rainy and dry seasons. As the results of checks against overturning and sliding, the retaining wall with. the new gabion system could produce suitable factors of safety for overturning and sliding. Vegetation established on the surface of the new gabion systems indirectly can help to increase slope stability by prevention of surface erosion. Consequently, the new gabion system with vegetation base materials could achieve the desired effect on slope stabilization as much as existing gab ion system could do, and could promote rapid establishment of vegetation on cut-slopes.

• Geomechanics and Engineering
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• v.24 no.6
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• pp.531-543
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• 2021

Freezing and thawing of pore water within backfill can affect the stability of retaining wall as the phase change of pore water causes changes in the mechanical characteristics of backfill material. In this study, the effects of freezing and thawing on the mechanical performance of retaining wall with granular backfill were investigated for various temperature and groundwater level (GWL) conditions. The thermal and mechanical finite element analyses were performed by assigning the coefficient of lateral earth pressure according to phase change of soil for at-rest, active and passive stress states. For the at-rest condition, the mobilized lateral stress and overturning moment changed markedly during freezing and thawing. Active-state displacements for the thawed condition were larger than for the unfrozen condition whereas the effect of freezing and thawing was small for the passive condition. GWL affected significantly the lateral force and overturning moment (Mo) acting on the wall during freezing and thawing, indicating that the reduction of safety margin and wall collapse due to freezing and thawing can occur in sudden, unexpected patterns. The beneficial effect of an insulation layer between the retaining wall and the backfill in reducing the heat conduction from the wall face was also investigated and presented.

• Earthquakes and Structures
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• v.3 no.3_4
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• pp.457-471
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• 2012

Current code procedures for stress and stability analysis of new and existing concrete-gravity dams are primarily based on conventional methods of analysis. Such methods can be applied in a straightforward manner but there has been evidence that they may be inaccurate or, possibly, not conservative. This paper presents finite element modeling and analysis procedures and makes recommendations for local failure criteria at the dam-rock interface aimed at predicting more accurately the behavior of dams under hydraulic and anchoring loads.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.87-94
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• 2006

In this study we carried out to analyze the effect of wind load on the structural stability of a container crane according to the change of the boom shape using wind tunnel test and provided a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load at 75m/s wind velocity is applied on a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary-layer wind tunnel with $11.52m^2$ cross-section area. Each directional drag and overturning moment coefficients were investigated and uplift forces at each supporting point due to the wind load were analyzed.

• Journal of Drive and Control
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• v.11 no.3
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• pp.22-30
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• 2014

In this research, the energy stability level method is used for examining the stable state of Field Robot under effects of swing motion, at particular postures of manipulator, and terrain conditions. The energy stability level is calculated by using the dynamic models of Field Robot, subjected to the concept of equilibrium plane and support boundary. The results, simulated by using computing program for estimating the potential overturning of Field Robot, supply useful predictions of stability analysis for designers and operators.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.549-556
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• 2002

Geotextile tubes hydraulically or mechanically filled with dredged materials have been applied in hydraulic and coastal engineering in recent years(shore protection structure, detached breakwater, groins and jetty). It can also be used to isolate contaminated material from harbor, detention basin dredging, and to use this unit as dikes for reclamation work. Recently, new preliminary design criteria supported by model and prototype tests, and some stability analysis calculations have been studied. The stability analysis of geotextile tube is composed geotechnical and hydrodynamic analysis. The stability check points are sliding failure, overturning, bearing capacity failure against the wave attack. In this paper presented the construction procedure and in-situ measurement(properties of filling material, effective height variation, stress variation at geotextile tube bottom) of geotextile tube at Young-Jin Bay and stability analysis by theoretical method and hydraulic model tests