• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.12
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• pp.1082-1088
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• 2007

Demand for high speed sea transportation modes has been increased dramatically last few decades. The WIG(Wing-in-ground effect) is considered as next generation maritime transportation system. In the structural design of high speed marine vessels, an estimation of water impact loads is essential. The dynamic structural responses of the WIG excited by the water impact loads may bring an important contribution to their damage process. The work presented in this paper is focused on the numerical simulation of the water impact on the WIG craft when it lands. It is aimed to study the structural responses of the WIG craft subjected to the water impact loads. The Arbitrary Lagrangian-Eulerian (ALE) finite element method is used to simulate the water impact of the WIG craft during a landing phase. A full 3D shell element is used to model the WIG craft in carbon composites, and a developed FE model is used to investigate the effect of the water impact loads on the structural responses of the WIG craft. In the analysis, two different landing scenarios are considered and their effects on the structural responses are investigated.

• Geotechnical Engineering
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• v.7 no.3
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• pp.43-50
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• 1991

To analyze the effects of ground water levels and external loads on the stability of a Dia- phragm wall, the three models of Bell, Piaskowski/kowalewski, and Washbourne were modified and extended to develop a new program SL3D. Comparing to the other two models, Washbourne's model shows the stability in on safes at the beginning of the excavation and increase as the excavation continue . Also the effects of various design factors, such as the density of slurry, ground water levels, the friction angle of soil, external loads and the length of trench, have been analyzed and a nomogram was developed.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.245-252
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• 2013

The purpose of this study was to analyze the effect that various loads have on the lower limb biomechanics. The following variables were measured and analyzed; performance time for each phase, lower limb moments and joint angles, and ground reaction forces. The kinematic and kinetic data was recorded by 2 force platforms and a motion capture system while 12 healthy adults in their twenties stepped down three steps under loads of 0%, 10%, 20% BW. Results are as follows. First, the different loading conditions did not seem to significantly affect the performance times and the joint angles. Second, the largest ground reaction forces were observed at the 1 step at the 10% BW condition. Finally, at the 0% BW loading condition the right hip extension moment was the smallest and the left hip flexion moment was the largest. The results show that there are not any significant changes in the biomechanics of the lower limbs under loading conditions up to 20% BW. Further investigations including more loading conditions with more weights and more additional steps analyzed are needed.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.93-99
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• 2006

Centrifuge model experiments were performed to investigate the confining effects of the sheet piles, installed to the sides of soft clay ground treated with sand compaction piles, on the bearing capacity and concentration ratio of composite ground. For the given g-level in the centrifuge model tests, replacement ratio of SCP and the width of surcharge loads on the surface of ground with SCP, the confining effects of installing the sheet piles on the edges of SCP ground on the bearing capacity, change of stress concentration ratio and failure mechanism were investigated. Kaolin, one of typical clay mineral, and Jumunjin standard sand were used as a soft clay ground and sand compaction pile irrespectively. As results of experiments, lateral confining effect by inserting the model sheet piles fixed to the loading plate was observed. For the strip surcharge loading condition, the yielding stress intensity in the form of the strip surcharge loads tends to increase with increasing the embedded depth of sheet piles. The stress concentration ratio was found not to be influenced consistently with the embedded depth of sheet piles whereas the effect of stress intensity on stress concentration ratio shows the general trend that values of stress concentration ratio are relatively high at the initial stage of loading and tend to decrease and converge to the certain values. For the failure mechanism in the case of reinforced with sheet piles, displacement behavior related to the punching failure, settlement right beneath the loading plate occurred since the soil was confined with sheet piles, was observed.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.109-114
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• 2003

It is the common practice to reinforce excessively the secondary tunnel lining due to the lack of rational insights into the ground loosening loads. The main load of the secondary lining for drained-type tunnels is the ground loosening. The main cause of the load for secondary tunnel lining is the deterioration of the primary support members such as shotcrete, steel ribs, and rockbolts. Accordingly, the development of the analysis model to consider the ground-primary supports-secondary lining interaction is very important for the rational design of the secondary tunnel lining. In this paper, the interaction is conceptually described by the simple mass-spring model and the load transfer from the primary supports to the ground and the secondary lining is showed by the characteristic curves including the secondary lining reaction curve for the theoretical solution of a circular tunnel. And also, the application of this model to numerical analysis is verified in order to review the potential tool for practical tunnel problems with the complex conditions like non-circular shaped tunnels, multi-layered ground, sequential excavation and so on.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.77-81
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• 2000

The purpose of this paper is to describe a new measuring method of ground resistance for the grounding system in energized power equipment and substations. It is very difficult to measure the accurate ground resistance in energized power equipment and substations because of the noise conducted from all external connections to the grounding system and harmonics components caused by unbalanced loads and overloads. The ground resistance that is measured with existing methods includes not only the effect of desired signals but also noise components for the measurement period in grounding system. The measured value of ground resistance can entirely be different from actual value. In this paper, to eliminate 60[Hz] power system interference and harmonic components the low-pass filter method was used in the measurement of ground resistance.

• Journal of the Korean GEO-environmental Society
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• v.24 no.10
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• pp.41-49
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• 2023

Structures such as bridge columns installed on the asymmetric ground such as mountain areas and sloping ground are subject to various loads such as wind, temperature, earthquake, and etc. The pile foundation is generally applied to bridge columns on the asymmetric ground in order to stably support structures. The behavior of the pile foundation supporting bridge columns changes due to various load conditions. In particular, ground-pile-structure interactions should be studied to analyze the behavior of the pile foundation that supports bridge columns effected by dynamic loads such as earthquakes. The pile foundation installed on the asymmetric ground effected by the earthquake has the complicated dynamic interaction between the foundation and the ground due to the ground slope, the difference in soil resistance according to the shaking direction, and the ground movements. In this study, the 1g shaking table tests were conducted to confirm the effect of the slope of the sloping ground on the dynamic behavior of group piles supporting the superstructure installed at the berm of the sloping sandy soil which is the asymmetric ground. The result shows that the acceleration of the pile cap and the superstructure decrease as the slope of the sloping ground increase, and the slope of the dynamic p-y curve of the pile decrease.

• International Journal of High-Rise Buildings
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• v.1 no.1
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• pp.21-28
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• 2012

Diagrid system has been in the spotlight for its superiority in terms of the resistance to lateral force when applied to skyscrapers. In diagrid system, most of columns can be eliminated because vertical loads (gravity loads) and horizontal loads (lateral loads) are delivered simultaneously thanks to the triangular shape of diagrid. However, lack of studies on connection shape and node connection details makes it hard to employ the system to the buildings. In this study, the structural safety of the node connections in circular steel tube diagrid system which has been considered in the Cyclone Tower in Korea (Seven stories below and fifty-one above the ground) was evaluated using the 4 full-scale specimens. The parameters are the extended length (20 mm, 40 mm & 60 mm), thickness (40 mm & 50 mm).

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.89-96
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• 2001

A concrete lining of NATM tunnel is the final product of a process that involves planning and evaluation of user needs, geotechnical investigations, analysis of ground-lining interaction, construction, and observations and modifications during construction. The designer must consider the lining in context of the many function, construction, and geotechnical requirements. Also, the loss of supporting capacity of shotcrete lining due to poor rock qualities and shotcrete erosion must be considered. The values, shapes, and estimating methods of rock load and water pressure are very different with every designers. Estimating methods of rock loads used in the design of NATM tunnel concrete lining are investigated. Numerical analyses are done in various conditions. And the rock loads estimated from radial stress and plastic zone are compared respectively.

• Earthquakes and Structures
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• v.11 no.6
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• pp.1061-1076
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• 2016

Prefabricated Modular Buildings are increasingly becoming popular in the construction industry as a method to achieve financially economical buildings in a very short construction time. This increasing demand for modular construction has expanded into multi-storey applications where the effect of lateral loads such as seismic loads becomes critical. However, there is a lack of detailed scientific research that has explored the behaviour of modular buildings and their connection systems against seismic loads. This paper will therefore present the nonlinear time history analysis of a multi-storey modular building against several ground motion records. The critical elements that need special attention in designing a modular building in similar seismic conditions is discussed with a deeper explanation of the behaviour of the overall system.