• Steel and Composite Structures
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• 제3권2호
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• pp.141-152
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• 2003

The ski jump in Innsbruck known for the famous annual New Year "Four-ski-jump-tournament" has been fully renewed. The original jumping tower (built for the 1976 Olympic winter games) was fully pulled down and a new landmark similar to a lighthouse has been erected located on a small hill at the border of the city. Zaha Hadid(London) won the international architectural competition for this significant building. The constructional realisation has been ordered from Aste Konstruktion and has been finally honoured with the Austrian state award for consulting 2002. After a very strict timetable the building was already handed restaurant at the top.

• Journal of Welding and Joining
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• 제33권3호
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• pp.4-11
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• 2015

The offshore wind power plants are watched as a new market to accomplish the needed energy, bringing technical and economical challenges. Advanced countries in the field of wind industry are now appling the 600 MPa, 150~200 mm thick high strength steel to offshore wind power plants. Moreover, the high efficient welding methods which is weldable ultra tick high strength steel with 1 pass welding are developed and applied in manufacturing the offshore wind tower. This article deals with the present world wide status of offshore power plants and the tendency of the development of high efficient welding technology for constructing the offshore wind tower. This article intends to offer the materials for development and raising of the domestic offshore wind power technology.

• 한국강구조학회 논문집
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• 제20권3호
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• pp.421-435
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• 2008

본 논문에서는 잔류응력과 초기변형을 고려한 비선형 해석을 실시하여 송전철탑의 극한거동을 분석하였다. 송전철탑 전체 해석 모델링에 주주재, 수평재 및 1차 사재는 보(Beam)요소를 사용하였고, 기타 사재 및 보조재는 트러스(Truss)요소를 사용하였으며 구조해석프로그램 ABAQUS(2004)를 사용하였다. ABAQUS Imperfection 옵션 및 Initial condition 옵션을 사용한 초기변형 및 잔류응력 적용의 적절성을 평가하고자 판(Plate & Shell)요소 부재모델과 보요소 부재모델의 해석결과를 비교분석하였다. 보요소와 트러스 요소를 적용한 송전철탑 전체모델의 비선형 해석결과 ${P-{\triangle}}$효과로 인하여 철탑 하부 각재부 주요 부재에 좌굴파괴가 발생하였다. 본 연구에서는 구조물의 안전성에 영향을 미치는 비선형 해석인자 즉 잔류응력과 초기변형의 정도에 따른 안전성 저하값을 정량적으로 평가하여 제시하고 있다. 그러므로, 본 연구의 결과는 실제 송전철탑의 파괴극한거동에 가까운 설계법, 해석법 및 시공법 정립에 크게 기여할 것으로 판단된다.

• 건축사
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• 통권531호
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• pp.60-67
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• 2013

• Structural Engineering and Mechanics
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• 제81권2호
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• pp.147-161
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• 2022

The Brace-Type Shear Fuse (BSF) device is a newly proposed steel damper with excellent cumulative ductility and stable energy dissipation. In consideration of the current situation where there are not many alternatives for transversal seismic devices used in long-span three-tower self-anchored bridges (TSSBs), this paper implements improved BSFs into the world's longest TSSB, named Jinan Fenghuang Yellow River Bridge. The new details of the BSF are developed for the TSSB, and the force-displacement hysteretic curves of the BSFs are obtained using finite element (FE) simulations. A three-dimensional refined finite element model for the research TSSB was established in SAP2000, and the effects of BSFs on dynamic characteristics and seismic response of the TSSB under different site conditions were investigated by the numerical simulation method. The results show that remarkable controlling effects of BSFs on seismic response of TSSBs under different site conditions were obtained. Compared with the case without BSFs, the TSSB installed with BSFs has mitigation ratios of the tower top displacement, lateral girder displacement, tower bending moment and tower shear force exceeding 95%, 78%, 330% and 346%, respectively. Meanwhile, BSFs have a sufficient restoring force mechanism with a minor post-earthquake residual displacement. The proposed BSFs exhibit good application prospects in long-span TSSBs.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.687-696
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• 2005

Safety diagnosis was conducted to evaluate the long-term stability evaluation of power transmission tower of which deformation of the upper structural elements occurred. To assess the cause of the structural deformation, field investigation including BIPS, down-hole test, concrete pile coring and finite element analysis were carried out. From these studies, the major cause of deformation was found due to the heavily fractured layer and weathered soil topography at the pile tip area. The cement-milk grouting method was proposed to reinforce these weak zone around the pile tip area. Also, the increase of cross-section and stiffness for steel members of upper tower structures was suggested. Instrumental monitoring was proposed as well to verify reinforcing effect.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.344-346
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• 2001

The sharing of common corridors by electric power transmission lines and pipelines is becoming more common place. However, such corridor sharing can result in undesired coupling of electromagnetic energy from the power lines to the near facilities. During a fault on any of the transmission lines, energization of the earth by supporting structures near the fault can result in large voltages appearing locally between the earth and the steel wall of any nearby pipeline. This paper presents the outline of the tower footings for the transmission lines having been used in KEPCO and analyzes the earth resistance for operation method of the tower footing, that is contact presence for the anchor and reinforcing rob of the tower and foundation presence of the underground wiring.

• 한국강구조학회 논문집
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• 제20권3호
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• pp.389-398
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• 2008

현행 송전철탑의 경우 허용응력 설계개념을 도입한 철탑설계기준을 적용하여 설계, 제작되고 있으나 탄성해석을 전제로 한 허용응력 설계기법으로는 송전철탑의 명확한 도괴 원인을 규명할 수가 없다. 철탑 도괴의 원인을 규명하기 위해서는 철탑 부 재 및 접합부의 재료 및 기하학적 비선형성을 고려한 2차 변형효과를 고려하여야 한다. 2차 변형에 영향을 주는 요인으로는 부재의 잔류응력, 초기변형, 접합부의 단부구속도 등이 있으며 이는 비선형 대변형 해석을 통하여 거동 파악이 가능하다. 본 연구에서는 선형해석과 비선형해석의 비교를 통하여 비선형 해석의 필요성을 확인하고 비선형 유한요소해석에 따르는 해석상의 복잡함을 줄이기 위해서 등가비선형 해석기법을 개발하고 이로부터 도출된 철탑의 극한하중을 비선형 유한요소해석의 극한하중과 비교를 함으로써 개발기법의 신뢰성을 확인하였다. 개발된 해석기법을 바탕으로 사재의 축력 및 세장비가 주주재의 최대내력에 미치는 영향을 파악하고 실무적 편의성을 제공하기 위하여 이를 도표화 하였다.

• 자원리싸이클링
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• 제26권5호
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• pp.48-53
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• 2017

전기로 제강 공정에서 분진은 제강생산량의 1 ~ 2%가 발생하고 있으며, 분진 중에는 유가금속인 Zn과 Fe가 20 ~ 30% 정도 함유되어 있다. 전기로 배가스에 포함된 분진은 전기로 출구 덕트를 빠져나와 배가스를 완전연소하기 위한 연소탑과 냉각을 위한 냉각탑을 거쳐 Bag filter에 포집된다. 연소탑 하단에서 비중 차이에 의해 포집되는 분진은 전체 발생량의 15%에 해당하며 기존 Bag filter 분진보다 고가로 위탁처리 되고 있다. 본 연구는 연소탑 하단에 포집되는 분진의 유가금속 분리 회수에 대한 연구로서, 전기로 조업 시점과 분진의 입도에 따른 성분을 분석하여 유가금속의 함량 차이를 비교하였다. 본 연구 결과 전기로 조업 시점에 따른 영향 보다는 입도에 따라 Zn과 Fe의 함량에 큰 차이를 보였다.

• Steel and Composite Structures
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• 제41권5호
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• pp.681-695
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• 2021

Many existing transmission or communication towers designed several decades ago have undergone nonreversible performance degradation, making it hardly meet the additional requirements from upgrades in wind load design codes and extra services of electricity and communication. Therefore, a new-type non-destructive reinforcement method was proposed to reduce the on-site operation of drilling and welding for improving the quality and efficiency of reinforcement. Six built-up steel angle members were tested under compression to examine the reinforcement performance. Subsequently, the cyclic loading test was conducted on a pair of steel angle tower sub-structures to investigate the reinforcement effect, and a simplified prediction method was finally established for calculating the buckling bearing capacity of those new-type retrofitted built-up steel angles. The results indicates that: no apparent difference exists in the initial stiffness for the built-up specimens compared to the unreinforced steel angles; retrofitting the steel angles by single-bolt clamps can guarantee a relatively reasonable reinforcement effect and is suggested for the reduced additional weight and higher construction efficiency; for the substructure test, the latticed substructure retrofitted by the proposed reinforcement method significantly improves the lateral stiffness, the non-deformability and energy dissipation capacity; moreover, an apparent pinching behavior exists in the hysteretic loops, and there is no obvious yield plateau in the skeleton curves; finally, the accuracy validation result indicates that the proposed theoretical model achieves a reasonable agreement with the test results. Accordingly, this study can provide valuable references for the design and application of the non-destructive upgrading project of steel angle towers.