• The Journal of Engineering Geology
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• v.21 no.2
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• pp.117-124
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• 2011

Soil deformations such as settlement, heaving and lateral flow have frequently happened on marine reclaimed soft grounds due to embankment filling or banking. The electrical resistivity survey was applied to investigate on ground surface such soil deformation without disturbance of ground. A test embankment was performed to assess soil deformation in marine reclaimed soft grounds, where was located at Sihwa area in western coast of Korean peninsula. The soft ground was composed of clayey sediments. After embankment filling, the boundary of soil deformation affected by the filling could be investigated with application of the electrical resistivity survey. The result of electric resistivity survey shows that the extent of deformation is about 5 m laterally to the southern direction of embankment and about 5~6 m vertically in depth, which is about 1-1.2 times of embankment height. This shows that the electric resistivity survey can be applied to interpret the ground deformation in a soft ground region.

• Journal of the Korea Computer Graphics Society
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• v.20 no.1
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• pp.1-11
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• 2014

Patients with cerebral palsy or arthritis have deformities in lower limb which cause unstable gait or posture and pains. Surgeons perform a deformity correction osteotomy with surgical plan. But sometimes they find the unexpected angular or rotational deformation after surgery. The problems are that there is no method to predict the result of a surgical plan and also there are so many factors to must consider in surgical planning step such as clinical measurements, rotation angle, wedge angle, morphology of lower limb, etc. This paper presents new methods for planning the deformity correction osteotomy efficiently. There are two approaches based on the 3D mesh model and the accurate assessment of the patient's lower limb. One is the manual pre-simulation of surgery using forward kinematics. And the other is the automatic surgical planning using inverse kinematics and nonlinear optimization. Using these methods, we can predict and verify the results of various surgical treatments and also we can find a more effective surgical plan easily compared to conventional methods.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.6
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• pp.11-20
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• 2013

In this paper, the quantitative damage index for reinforced concrete (RC) columns with non-seismic details were presented. They are necessary to carry out the postearthquake safety evaluation of RC buildings under 5 stories without seismic details. The static cyclic test of the RC frame sub-assemblage that was an one span and actual-sized was first conducted. The specimen collapsed by the shear failure after flexural yielding of a column, lots of cracks on the surfaces of columns and beam-column joints and the cover concrete splitting at the bottom of columns occurred. The damage levels of these kinds of columns with non-seismic details were classified to five based on the load-displacement relationship by the test result. The residual story drift ratios and crack widths were then adapted as the quantitative index to evaluate the damage limit states because those values were comparatively easy to measure right after earthquakes. The highest one among the residual story drift ratios under the similar maximum story drift ratio decided on the residual story drift ratio of each damage limit state. On the other hand, the lowest and average ones among the respective residual shear and flexural widths under the similar maximum story drift ratio decided on the residual shear and flexural widths of each damage limit state, respectively. These values for each damage limit state resulted in being smaller than those by the international damage evaluation guidelines that are for seismically designed members under the same deformations.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.5
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• pp.59-69
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• 2013

본 연구에서는 동적 점탄-점소성 구성식에 기초한 다층지반의 1차원 액상화 해석을 수행하였다. 일본 고베 포트아일랜드에서 발생한 1995 Hyogoken Nanbu 지진에 대하여 지반 모델링을 하였으며, 사질토 지반에는 탄소성 모델을, 점성토 지반에는 점탄-점소성 모델 및 탄-점소성 모델을 각각 적용하였다. 본 연구 결과, 모델 지반의 경우 지표 10 m 아래를 전후하여 액상화가 발생하였으며 액상화가 발생한 지반을 통과하는 지진파는 감쇠특성을 나타내고 이 때 전단변형률을 크게 증가시켰다. 또한, 대변형률 영역에서의 점성토의 동적거동 해석에서는 점소성 거동특성이 지배적이므로 점소성 모델의 적용이 중요함을 알 수 있었다. 한편 동적 점탄-점소성 구성모델은 대변형률 영역에서 점성토의 소성변형을 유발하는 대형 지진 발생시 점성토의 증폭 및 감쇠특성 분석에 적용 가능한 모델임을 확인하였다.

• Geotechnical Engineering
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• v.1 no.1
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• pp.31-46
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• 1985

An extensive program of tunnel instrumentation has been Implemented in the construction of the Seoul Subway Line 3 and 4, in which the NATM was adopted as the main tunnelling technique. Among more than ten instrumented sections in the downtown area, five representative test sections were selected for analysis in this study, with an emphasis on the surface settlement and crown settlement. Variations of the surface and crown settlement. Variations of the governing factors, such as ground conditions, tunnel geometry, and construction conditions are described in this paper. Possible mechanisms for ground deformations occurring at different stages of tunnel construction are formulated, based on overall interpretation of the field observations and data obtained.

• Geotechnical Engineering
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• v.1 no.2
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• pp.81-92
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• 1985

Braced excavation for a new building was carried out at a very close proximity of an existing tall building of T.hick columns are supported by indict.ideal spread footings on sand layer The excavation was planned to reach far below the footing level of the existing building. To assess the foundation performance and stability of the existing building, the behavior of 9round subjected to loss of confinement from excavation was analytically studied using finite element method. Field instrumentation was also conducted to monitor the actual ground responses during excavation. Based on these studies, various remedial measures weere taken to minimize the adverse effects to the building, and excavation was successfully completed. This paper presents the results from the analytical studies and field monitoring, and measured and measured responses at different stages of excavation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.3
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• pp.333-342
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• 2003

The objective of this paper is to present an algorithm to locate and size damage in a beam structure. The method uses the changes in the modal strain energy distribution. A damage index, utilized to identify possible location and corresponding severity of local damage, is formulated and expressed in terms of modal displacements that can be obtained from mode shapes of the undamaged and the damaged structures. The possible damage locations in the structure arc determined by the application of damage indicator according to previously developed decision rules. The robustness and effectiveness of the method arc demonstrated using numerical examples of beam structures with simulated damage.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.237-249
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• 2002

Nonlinearity and anisotropy of soil should be considered for the exact prediction of deformation before the failure state. In this study, a new constitutive model is developed in which the nonlinearity of soil is formulated by Ramberg-Osgood equation and the soil anisotropy is implemented by the cross-anisotropic elasticity. Nonlinear anisotropic model and other models for comparison are used to analyze the simple boundary value problems and the circular footing problem. In the results, the anisotropic ratio of elastic modulus is a key value for the bulk modulus of soil, the coeffcient of earth pressure at rest, and the slope of effective stress paths. Furthermore, it is found that the nonlinearity of soil considering the in-situ stresses has the great influence on the magnitude of settlements.

• Journal of the Korean Data and Information Science Society
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• v.23 no.6
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• pp.1065-1074
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• 2012

The purpose of this paper is to statistically analyze the effects of on-base and slugging ability on the run productivity in Korean professional baseball. In Section 2, we have investigated the OPS (On-base percentage Plus Slugging average) and introduced new indices of batting ability by modifying the OPS. In Section 3, we have examined the correlation which the batting average, on-base percentage, slugging average, IsoP (Isolated Power), OPS and the indices introduced in Section 2 have with the average runs per game, using the data from all the games of the regular seasons in 2007~2011. In addition, by generalizing the OPS and the indices introduced in Section 2, we have analyzed the correlation of the indices with various weights between the average runs per game. As a result, the weighted OPS consisting of on-base percentage (with weight 57%) and slugging average (with weight 43%) has been found to give the best explanation of the run productivity.

• Spatial Information Research
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• v.23 no.5
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• pp.75-85
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• 2015

Recently deformed or destroyed of soundproof wall by local winds and typhoon has increased. This research proposed the estimation method of the design wind load of soundproof wall using spatial information analysis based on 1:5,000 digital map and performed comparative analysis with actual application cases. According to the result of quantitative evaluation using GIS, the surface roughness in the downtown area packed with buildings was III and the surface roughness in the suburban district with a relatively small number of buildings was II and the surface roughness in the district packed with open areas and typical farmhouses was I. This shows that the wind load of the soundproof walls reflecting the actual surface conditions was estimated. If the quantitative GIS analysis presented in this study is applied to wind-resistant design of soundproof walls, it is supposed that this will be helpful in more rational wind-resistant design by remedying the existing problem in which the wind load varies depending on designer's subjectivity.