• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.411-416
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• 2000

The behavior of high strength reinforced concrete columns subjected to uniaxal reversal loading and biaxial reversal circle path loading was investigated. Four full scale test specimens were tested. All specimens were adopted cantilever type, in order that the critical region is to locate only at the bottom of column. The parameters studied were transverse reinforcement ratio, uniaxial lateral loading and biaxial lateral loading. The damage features of columns by the biaxial loading are different from those of the uniaxial loading, However, the maximum strength and the draft angle at maximum strength were almost the same under uniaxial and biaxial loading. The transverse reinforcement under biaxial loading was very effective for increasing ductility of specimens.

• 한국지반환경공학회 논문집
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• 제7권2호
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• pp.15-24
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• 2006

본 연구에서는 수평재하시험과 공내수평재하시험 결과를 이용하여 지반반력계수를 각각 분석하였다. 또한 이들 값과 수평재하시험 실시 위치에서의 N치를 이용하여 도로교표준시방서, 일본토목학회, Hukuoka식, 일본도로협회 제안식으로 산정한 수평방향 지반반력계수를 비교 및 분석하여 제안식별 적용성을 평가하고자 하였다. 수평방향 지반반력계수 산정시 지반의 변형계수가 큰 영향을 미치는 것으로 볼 때 합리적인 지반의 변형계수 산정이 매우 중요하며, 제안식별 변형계수 적용에 대해 재하시험 결과를 이용하여 검토하였다. 특히 공내수평재하시험 결과를 이용하여 지반반력계수를 산정하는 방법은 수평변위를 고려할 수 없는 등의 문제점이 있는 것으로 나타나 사질토 지반의 수평방향 지반반력계수 산정시 말뚝의 직경과 수평변위를 고려할 수 있는 식을 제안하였으며, 아울러 N치를 이용한 지반의 변형계수를 고려하는 제안식에 대해서는 수평재하시험과 비교하여 지반의 변형계수 추정식을 제안하였다.

• Structural Engineering and Mechanics
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• 제12권2호
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• pp.157-168
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• 2001

In this paper, experimental investigation into the behavior of reinforced concrete (RC) columns tested under large lateral displacement with four different types of loading arrangements is presented. Each loading arrangement has a different system for controlling the consistency of the loading condition. One of the loading arrangements used three units of link mechanism to control the parallelism of the top and bottom stub of column during testing, and the remaining employed eight hydraulic jacks for the same purpose. The loading systems condition used in this investigation were similar to the actual case in a moment-resisting frame where the tested column was displaced in a double curvature. Ten model column specimens, divided into four series were prepared. Two columns were tested monotonically until collapse, and unless failure took place at an earlier stage of loading, the remaining eight columns were tested under cyclic loading. Test results indicated that the proposed system to keep the top and bottom stubs parallel during testing performed well.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.36-43
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• 2004

Most of pile foundations are fixed head condition, but lateral loading test for pile is performed under free head condition generally In this study, a lateral loading test for a large diameter drilled shaft was performed under the fixed pile head and the free pile head condition, where lateral displacement along the pile depth was measure. Test results and theoretical values were compared and analyzed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.81-84
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• 2008

The purposes of this study are to verify a reasonable model of material characteristic and to propose a rational model of reinforcement characteristic considering monotonic and cyclic loading about manufactured reinforcing steel in Korea. Longitudinal reinforcements of the plastic hinge region were behaved tensile deformation and compressional deformation by direction of lateral loading. However Confinement steels were behaved only tensile deformation by lateral loading. Transverse steels were laid the state of tension in the lateral loading of time, and they were laid state that stress is zero when it was removed lateral load. The tests for cyclic tension loading were performed for test variable as yield strength and reinforcement bar sizes. It was estimated that the total strain energy per unit volume was 74 $MJ/m^3$. The modified ultimate concrete compression strain model was proposed based on experimental study of cyclic tension test for manufactured reinforcing steel in Korea.

• Steel and Composite Structures
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• 제1권1호
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• pp.145-158
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• 2001

An experimental study was conducted to evaluate the effects of loading sequence and lateral bracing on the behavior of reduced beam section (RBS) steel moment frame connections. Four full-scale moment connections were cyclically tested-two with a standard loading history and the other two with a near-fault loading history. All specimens reached at least 0.03 radian of plastic rotation without brittle fracture of the beam flange groove welds. Two specimens tested with the nearfault loading protocol reached at least 0.05 radian of plastic rotation, and both experienced smaller buckling amplitudes at comparable drift levels. Energy dissipation capacities were insensitive to the types of loading protocol used. Adding a lateral bracing near the RBS region produced a higher plastic rotation; the strength degradation and buckling amplitude were reduced. A non-linear finite element analysis of a one-and-a-half-bay beam-column subassembly was also conducted to study the system restraint effect. The study showed that the axial restraint of the beam could significantly reduce the strength degradation and buckling amplitude at higher deformation levels.

• 한국지반공학회논문집
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• 제27권4호
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• pp.67-76
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• 2011

본 연구에서는 수치해석 방법을 통하여 점성토, 사질토, 그리고 점성토와 사질토의 혼합지반에 대하여 상부, 중간, 하부의 하중 작용위치에 따른 석션기초의 극한 수평저항력 및 거동을 분석하였다. 해석결과 지반조건에 관계없이 중간 위치에 재하시 가장 큰 수평저항력을 발휘하는 것으로 나타났으며, 사질토층의 극한저항력이 점성토층이나 점성토-사질토층에 비해 상대적으로 큰 값을 나타내었다. 그리고 석션기초의 이동량과 회전량 분석결과 석션기초의 이동량은 재하위치와 지반조건 모두에 대해 영향을 받지만, 회전량은 지반조건에 관계없이 재하위치에 가장 큰 영향을 받는 것으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1011-1016
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• 2009

In this study, to performed laboratory model tests in order to verify on load transfer condition of drilled shaft under lateral loading. To conducted model test on polystyle drilled shaft under multi layer ground conditions. In model test, to measured the strain of drilled shaft and displacement under later loading. In order to verify on model test results, to conduct the numerical analysis.

• Structural Engineering and Mechanics
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• 제48권2호
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• pp.275-289
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• 2013

The cross sections of multi-span beams are sometimes suddenly increased at the interior support of continuous beams to resist high negative moment. An earlier study on elastic lateral torsional buckling of stepped beams was conducted to propose new design equations. This research aims to continue the earlier study by considering the effect of inelastic buckling of stepped beams subjected to pure bending and general loading condition. A three-dimensional finite element-program ABAQUS and a statistical program MINITAB were used in the development of new design equations. The inelastic lateral torsional buckling strengths of 36 and 27 models for singly and doubly stepped beams, respectively, were investigated. The general loading condition consists of 15 loading cases based on the number of inflection point within the unbraced length of the stepped beams. The combined effects of residual stresses and geometrical imperfection were also considered to evaluate the inelastic buckling strengths. The proposed equations in this study will definitely improve current design methods for the inelastic lateral-torsional buckling of stepped beams and will increase efficiency in building and bridge design.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권4호
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• pp.331-338
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• 2004

Stress transfer to the surrounding tissues is one of the factors involved in the design of dental implants. Unfortunately, insufficient data are available for stress transfer within the regenerated bone surrounding dental implants. The purpose of this study was to investigate the concentration of stresses within the regenerated bone surrounding the implant using three-dimensional finite element stress analysis method. Stress magnitude and contours within the regenerated bone were calculated. The $3.75{\times}10-mm$ implant (3i, USA) was used for this study and was assumed to be 100% osseointegrated, and was placed in mandibular bone and restored with a cast gold crown. Using ANSYS software revision 6.0, a program was written to generate a model simulating a cylindrical block section of the mandible 20 mm in height and 10 mm in diameter. The present study used a fine grid model incorporating elements between 165,148 and 253,604 and nodal points between 31,616 and 48,877. This study was simulated loads of 200N at the central fossa (A), at the outside point of the central fossa with resin filling into screw hole (B), and at the buccal cusp (C), in a vertical and $30^{\circ}$ lateral loading, respectively. The results were as follows; 1. In case the regenerated bone (bone quality type IV) was surrounded by bone quality type I and II, stresses were increased from loading point A to C in vertical loading. And stresses according to the depth of regenerated bone were distributed along the implant evenly in loading point A, concentrated on the top of the cylindrical collar loading point B and C in vertical loading. And, In case the regenerated bone (bone quality type IV) was surrounded by bone quality type III, stresses were increase from loading point A to C in vertical loading. And stresses according to the depth of regenerated bone were distributed along the implant evenly in loading point A, B and C in vertical loading. 2. In case the regenerated bone (bone quality type IV) was surrounded by bone quality type I and II, stresses were decreased from loading point A to C in lateral loading. Stresses according to the depth of regenerated bone were concentrated on the top of the cylindrical collar in loading point A and B, distributed along the implant evenly in loading point C in lateral loading. And, In case the regenerated bone (bone quality type IV) was surrounded by bone quality type III, stresses were decreased from loading point A to C in lateral loading. And stresses according to the depth of regenerated bone were distributed along the implant evenly in loading point A, B and C in lateral loading. In summary, these data indicate that both bone quality surrounding the regenerated bone adjacent to implant fixture and load direction applied on the prosthesis could influence concentration of stress within the regenerated bone surrounding the cylindrical type implant fixture.