High-strength bolt has high stiffness and fatigue strength. At this time, initial axial force is one of main factor to affect the strength and deformation behavior of connection. Therefore, the objective of this study is to investigate reduction of initial axial force in high-strength bolt under shear fatigue.

The purpose of this study was to analyze the reduction of clamping force of TS (torque shear) bolted connection under fatigue loading. Generally, TS bolt has been totally tightened by torque shear wrench. However the plant structures experienced various fatigue loadings that makes reduction of clamping force of TS bolt. Therefore, this study conducted to the fatigue load test.

The purpose of this study was to investigate deformation and reduction of initial clamping force in slip critical type connection under fatigue loading. And, the parameters of this study were the different clamping force and friction coefficient of surface of plate. As a result, the clamping force of all specimens were generally decreased in comparison with initial values under fatigue loading.

Some researchers suggested that bolt slippage occurred in column-tree connection type. In this paper, bolt slippage was evaluated on different depth of beam. When the length of beam set 7,500 mm equally, three depth of beams was 600, 500, 400mm, respectively. Also, column size of all specimens was same, and panel zones was strongly reinforced to evaluate bolt slippage in beams. As a result of full-scale testing, the bolt slippage of all specimens was occurred within plastic rotation ± 2.0%. It was showed that the effect of bolt slippage on depth of beam was slight.

The purpose of this study is to analyze the trend of domestic and foreign steel plate shear wall (SPSW) systems. The investigated countries were three, such as Korea, Canada, and U.S. The full scale or scale down specimens were preponderantly investigated. The details and performances of all specimens were compared for each other.

This paper presented to study used Abaqus on steel plate bonded reinforcement technology for column to beam connections, and then the result showed that steel plate bonded reinforcement technology has great reinforcement effect for RC column to beam joint. Also the steel plate bonded reinforcement technology was safety and convenient operation.

Steel moment-resisting frames are susceptible to large lateral displacements during severe earthquakes. However, frequent damage to concentrically braced frames in past earthquakes, such as the 1994 Northridge earthquakes, has raised concerns about the ultimate deformation capacity of this class of structure. Also, there is no way to accurately predict the behavior of the brace member in the event of earthquakes. Therefore, the objective of this study is to compare the performance of chevron braced frames when they are used in the upgrade of deficient RC frames.

The purpose of this paper is to check the safety of the scaffold structures used wire rope. The structural safety on the scaffold structures with wire rope and boiler furnace was evaluated. As a results, all assessment structures with wire ropes were checked to be safe.

In this paper, the seismic performance of existing column-tree connections using composite deck plate was experimentally evaluated. As a result, although two specimens were not founded the brittle fracture at the beam-to-column, composite slab were destroyed by crushing at the beam-to-column connection.

In this paper, the effects of beam splice location on seismic performance of column-tree connections were experimentally and analytically evaluated. The study results showed very little difference between the results of analytical and those of experimental.

By reducing the cross-sectional area of the splice plates, the weak-axis column-tree connections which plastic hinge was forced into the splice connection were proposed in this paper. The main objectives of this testing was to investigate the semi-rigid performance of weak-axis column-tree splice connection.

In this paper, the seismic performance of column-tree connections was experimentally evaluated, depending on location of plastic hinge. As a result, although two specimens were qualified for SMFs, beam-to-column connection and flange plate were detected the brittle fracture during 5% story drift ratio.

In this paper, in order to evaluate the seismic performance on semi-rigid column-tree type connections, the experimental results and the finite element analysis results were compared. As a results, both results were considerably similar.

In this study, the seismic performance of weak-axis column-tree moment resisting frame was experimentally investigated using RBS conception. As a result, two specimens were showed that enough energy dissipation and plastic rotation capacity. But bolt-slip didn’t happen anymore after story drift ratio of 3%.

In this study, the seismic performance of weak-axis steel moment connections was investigated through cyclic testing of two full-scale specimens by reducing flange plate thickness. As a result, two specimens were showed that enough energy dissipation capacity and ductility.

This paper presents analytical studies on the cyclic behavior of column-tree steel moment connections by FEA. The column-tree moment connections are composed shop welded beam-to-column connection and field bolted beam-to-beam splice. Two analytical model of column-tree moment connections were designed with beam splice lengths of 900mm and 1,100mm, which are roughly 1/6 and 1/7 of the span length of 7,500mm. In order to verify the FEA reliability, the analytical results was compared with experimental results. Meanwhile, the experimental results were understood better through analysis procedure.

For coupled shear walls, coupling beams are the first line of dissipation under earthquakes. So coupling beams are important energy dissipation component. When coupling beams have little depth-to-span ratio, routine coupling beams have less capacity of energy dissipation.There are less design methods for coupling beams with depth-to-span less than 2. In this paper a specimen with steel plate reinforcement coupling beam was designed and analyzed by means of FEM software ABAQUS.

고력볼트 길이-직경비가 5d 이상인 경우, 시험을 통한 결과를 활용하여 현장에서 볼트 체결을 하도록 권고하고 있을뿐 길이-직경비에 따른 별도의 규정 및 지침은 없다. 국내에서는 고력볼트 체결법으로 너트회전법이 아닌 토크관리법이 적용하고 있고 최근에는 KS B 2819의 ‘구조물용 토크-전단형 고장력 볼트’(이하, TS 고력볼트)가 주로 사용되고 있기 때문에 길이 인자에 따른 규정이 국외 기준에 비해 미비한 것이 현실이다. 따라서, 본 논문에서는 TS 고력볼트의 길이인자에 따른 적정 축력 도입을 위한 소요 너트회전각 및 토크를 분석하여 길이변수에 따른 특성을 평가하고자 한다. 실험결과의 분석에서는 통계분석 프로그램 Minitab을 활용하여 길이변수에 대한 유효성을 정량적으로 분석했다.

수치일기예보와 관측 시스템의 많은 발전에도 불구하고 안개 예측은 아직도 만족할 수준이 아니다. 본 연구에서는 기상청의 지상 안개 관측자료(1998~2007)를 이용하여 충청지방의 안개 발생 특성과 안개 발생에 영향을 주는 기상요소들에 대해 조사하였다. 또한 로지스틱 기법을 이용하여 계절별 안개예측 식을 개발하고 이를 검증하였다. 충청지역에서 연 평균 안개 발생일 수는 충주에서 56.5일, 추풍령에서 17.9일이 발생하는 등 강한 공간편차를 보이고 있다. 또한 대부분 지역에서 가을과 여름에 각각 최대와 최소로 발생하여 계절변동도 강하게 나타나고 있다. 안개의 발생은 주로 04~07시에 일어나고 지속시간은 약 3시간 반 정도이다. 다른 지역과 달리 서산에서는 바람이 강할 때도 안개가 발생하고 있어 이 지역에서는 이류무도 자주 발생함을 알 수 있다. 또한 강수발생 유무도 안개 발생에 많은 영향을 미침이 확인되었다. 로지스틱 안개예측 기법의 예측 수준을 2008년도 지상 관측자료를 이용하여 검증한 결과 현재 기상청의 예보 수준보다 향상된 예보 수준을 보였다.

고력볼트의 현장 조립시 볼트 구멍 간의 불일치로 인하여 볼트 구멍을 확장하는 경우가 빈번하게 발생하고 있으며, 이를 위해서 외국 기준에서는 볼트 구멍 크기, 형태, 하중 방향에 따라 미끄럼하중에 대한 규정을 따로 두고 있다. 그러나 우리나라의 경우 과대구멍에 대한 시방규정이나 이에 대한 접합부 특성에 관한 연구는 미흡한 실정이다. 따라서, 접합부재 표면처리와 볼트구멍 크기의 변화가 접합부 내력에 어떠한 영향을 미치는 지를 실험을 통해 정량적으로 평가할 필요가 있다. 본 연구에서는 볼트 구멍 크기 및 형태에 따른 접합부의 미끄럼하중의 변화와 체결 후, 장기축력이완의 경향을 분석하기 위하여 160시간 및 800시간 동안 고력볼트의 축력의 변화를 측정하였다. 본 실험대상 고력볼트로 KS B 2819에 규정된 TS(Torque Shear)형 고력볼트를 사용하였다. 표준 볼트구멍 대비 그 외 볼트구멍의 미끄럼하중의 변화는 10% 미만으로 나타났으며, 장기축력이완은 직경 2.5배의 슬롯구멍에서, 2.66%로 가장 높게 나타났다.