• Journal of Korean Society of Steel Construction
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• v.29 no.2
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• pp.147-158
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• 2017

The present study focused on the structural performance of newly developed prefabricated composite columns (PSRC composite column) using bolt-connected steel angles. Concentric axial loading tests were performed for four 2/3 scaled PSRC column specimens and two conventional SRC column specimens. The test parameters were the spacing and sectional configurations of lateral reinforcement, and width-to-thickness ratio of steel angles. The test results showed that the axial load-carrying capacity and deformation capacity of the PSRC column specimens were comparable to those of the conventional SRC column specimens. Closely spaced steel plates and Z-shaped steel plates for lateral reinforcement increased the deformation capacity of the PSRC column specimens. The load-carrying capacity was greater than the prediction by current design codes. Numerical analysis was performed for the specimens. The results agreed well with the test results in terms of initial stiffness, load-carrying capacity, except for strength degradation due to cover concrete spalling.

• Journal of Korean Society of Steel Construction
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• v.24 no.6
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• pp.647-657
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• 2012

Although nuclear power plant piping system is designed conforming to design specifications, the piping systems are deteriorated with increase in service life. In this study, monotonic and cyclic loading tests were carried out on TP316 stainless steel pipe specimens, and the effect of local wall thinning and cracking on failure behavior was investigated. In the tests, 0%, 35% and 75% wall thinning and cracking of initial thickness were artificially introduced to inside elbow and straight pipe specimens, and internal pressures of 20MPa were applied to simulate real operation condition. From the test results, the effect of local wall thinning and cracking on failure mode, ultimate load, number of cycle and strain energy was presented, and maximum bending moment was compared with allowable bending moment calculated by ASME code.

• Journal of the Korean Geotechnical Society
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• v.32 no.12
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• pp.69-78
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• 2016

A suction bucket foundation has been considered to be a potential foundation type for offshore wind turbines. A suction bucket foundation is usually installed in soft soil, so the accumulated displacement of the foundation may occur under long-term cyclic loads. In this study, a series of 1-g model tests were performed to analyze the accumulated rotation of suction bucket foundations under long-term cyclic horizontal loads. The dry model ground was prepared to have two different soil densities by air-pluviation method. The model tests were performed varying the embedment depth of the suction bucket, the soil density, and the amplitude of cyclic load. A one-way horizontal cyclic load was applied over $10^4$ cycles. Test results showed that the accumulated rotation of the suction bucket foundation increased with the increase in the number of cycles and load magnitudes. Based on the model test results, a new equation was proposed to evaluate the accumulated rotation of the suction bucket foundations in dry sandy ground under long-term cyclic horizontal loads.

• Journal of the Korean Geotechnical Society
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• v.27 no.3
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• pp.63-73
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• 2011

The behavior of laterally cyclic loaded piles is affected by the magnitude and number of cycles of cyclic lateral loads as well as loading method (1-way or 2-way loading). In this study, calibration chamber tests were carried out to investigate the effects of loading method of cyclic lateral loads on the behavior of piles driven into sand. Results of the chamber tests show that the permanent lateral displacement of 1-way cyclic loaded piles is developed in the same direction as the first loading, whereas that of 2-way cyclic loaded piles is developed in the reverse direction of the first loading. 1-way cyclic lateral loads cause a decrease of the ultimate lateral load capacity of piles, and 2-way cyclic lateral loads cause an increase of the ultimate lateral load capacity of piles. The change of ultimate lateral load capacity with loading method of cyclic lateral loads increases with increasing number of cycles. It is also observed that the 1-way cyclic loads generate greater maximum bending moment than 2-way cyclic loads for piles in cyclic loading step and generates smaller maximum bending moment for piles in the ultimate state. It can be attributed to the difference in compaction degree of the soil around the piles with loading method of cyclic lateral loads. In addition, it is founded that 1-way and 2-way cyclic lateral loads cause a decrease in the maximum bending moment of piles in the ultimate state compared with that of piles subjected to only monotonic loads.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.55.2-55.2
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• 2009

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4_1
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• pp.23-32
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• 1992

The objective of this study is to identify the quantitative relationships among the important physical factors associated with failure of steel members under strong seismic excitations through very low-cycle fatigue tests. Very low-cycle fatigue is meant to be structural fatigue causing cracks and rupture in about 5~30 cycle ranges. The angle specimen was subjected to repeated axial Ioad after undergoing inelastic buckling. The test results reveal that the energy absorption capacities vary heavily with the history of loading and the failure mode. The maximum values of residual local strain at the initiation of a visible crack due to the very low-cycle fatigue were of the order of 25~40%, regardless of loading patterns, deflection modes, and width-to-thickness ratios.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.103-106
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• 2011

국토해양부령 제320호인 건축물의 피난 방화구조 등의 기준에 관한 규칙 제 3조에서는 내화구조에 관한 세부기준을 정하고 있다. 이러한 법정내화구조 중에서 철골철망 모르타르조의 피복두께에 따른 내화성능 변화를 분석하기 위하여, 본 연구에서는 고온 재하하중조건에서 내화실험을 수행하였다. 철골조의 피복두께를 50 mm ${\cdot}$ 60 mm ${\cdot}$ 70 mm로 변화하여 내화실험을 수행하였으며, 재하하중비를 변화시킴으로 동일 피복두께에서의 내화성능 변화를 분석하고자 하였다. 실험결과 단면소성모멘트 대비 하중비 0.4 조건에서의 철골철망 모르타르조의 내화성능은 180분이 나왔으며, 피난 방화구조 등의 기준의 별표 1에서 정하고 있는 내화구조의 성능기준 중 최대 내화성능시간인 3시간을 확보하는 것으로 나타났다.

• Journal of the Korea Concrete Institute
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• v.27 no.2
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• pp.137-145
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• 2015

The slab-type precast modular bridge consists of the precast slab bridge modules which are connected in the transverse direction. The longitudinal joints between the precast slab bridge modules are filled with cast-in-place mortar. The construction of the slab-type precast modular bridge is completed by applying the prestressing force on the longitudinal joints. In this study, 4-points bending tests and 3-points bending tests were conducted to examine the effects of the prestressing force and the shape of joint on the flexural strength and crack serviceability of longitudinal joint. The results of 4-points bending tests showed that the flexural strength is affected by the prestressing force but not by the shape of join. From the results of 3-points bending tests by which the bending moment and the shear force are simultaneously applied on the joints of the specimens, it is observed that the shape of joint affects on the flexural strength and the crack behavior. The results of two types of bending tests confirmed that the prestressing force according to the design code is appropriate and the joint with two shear keys gives the better performances against the crack of joint.

• Journal of Korean Association for Spatial Structures
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• v.11 no.3
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• pp.67-76
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• 2011

Column base is very important part of steel structure because it transmits load to foundation in structure. Column base which is used frame construction in the inside and outside of the country is distributed into exposed-type, concrete encased and imbeded-type. Exposed-type column base is most profitable, if consider reuse and recycle of elements first of all. In this study, we proposed a new style exposed-type column base improved in performance for construction work and mechanical performance.

• Journal of the Korean Geotechnical Society
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• v.17 no.5
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• pp.5-16
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• 2001

소일네일링 구조물의 설계 및 안정해석에 관한 지금까지의 연구는 대부분 굴착 배면지반의 자중만을 고려하여 연구 개발된 굴착사면에 인접하여 하중이 재하되는 경우, 그의 거동에 관한 연구는 미비한 실정이다. 따라서 본 연구에서는 원심모형시험기를 사용하여 하중재하시 소일네일링 구조물의 거동과 파괴 메카니즘에 관한 매개변수적 실험을 실시하였다. 매개변수적 실험에서는 네일의 길이 및 간격, 네일의 설치각, 하중재하위치 등을 다양하게 변화시키면서 1g 상태에서 축소모형실험을 실시하는 한편, 30g 및 50g까지 중력수준을 증가시킨 상태에서 상재하중실험을 실시하였다. 실험으로부터 얻어진 결과를 바탕으로 하중-침하 특성, 매개변수의 변화에 따른 영향, 중력수준의 증가에 따른 영향, 파괴메카니즘 등을 비교 분석하였다.