• Structural Engineering and Mechanics
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• 제74권5호
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• pp.635-655
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• 2020

The sag effect of long stay cables is one of the key factors restricting further increase in the span of cable-stayed bridges. Based on the formerly proposed concept of long stay cables lifted by an auxiliary suspension cable in cross-strait cable-stayed bridges, corresponding static approximate calculations and analytical theory based on catenary and parabolic cable configurations are established. Taking a main span 1400 m cable-stayed bridge as the research object, three typical lifting conditions and the whole process of auxiliary cable lifting are analyzed and discussed. The results show that the sag effect is effectively reduced. The support efficiency is only improved when the cables are lifted above the original cable chord. Reduction of the horizontal component force of the cable is limited. The equivalent elastic modulus and the vertical support stiffness of the lifted cables are significantly increased with increased horizontal projection length and not sensitive to the change of the lifting point position. The scheme of lifting the cable to the chord midpoint is more economical because of the less steel required for the auxiliary suspension cable, but its effect on improving the vertical support efficiency is limited. The support efficiency is better when the cable is lifted to the cable end tangential to the original cable chord, but the lifting force and the cross-sectional area of the auxiliary suspension cable are doubled. The approximate calculation results of the lifted cables are very close to the numerical analysis results, which verifies the applicability of the approximation method proposed in this study. The results of parabolic approximation calculations are approximately equal to that of catenary cable geometry. As the parabolic approximation analysis theory of lifted cables is more convenient in mathematical processing, it is feasible to use parabolic approximation analysis theory as the analytical method for the conceptual design of lifted cables of super-long span cable-stayed bridges.

• Coupled systems mechanics
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• 제7권3호
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• pp.269-280
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• 2018

Post-earthquake damages investigation in past and recent earthquakes has illustrated that the ground motion spatial variation plays an important role in the structural response of long span bridges. For the structural control of seismic-induced vibrations of cable-stayed bridges, it is extremely important to include the effects of the ground motion spatial variation in the analysis for design of an effective control system. The feasibility and efficiency of different vibration control strategies for the cable-stayed bridge under multiple support excitations have been examined to enhance a structure's ability to withstand earthquake excitations. Comparison of the response due to non-uniform input ground motion with that due to uniform input demonstrates the importance of accounting for spatial variability of excitations. The performance of the optimized designed control systems for uniform input excitations gets worse dramatically over almost all of the evaluation criteria under multiple-support excitations.

• 한국정보통신학회논문지
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• 제12권11호
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• pp.1987-1992
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• 2008

현재 건조되고 있는 선박들은 선형이 고급화됨에 따라 시스템이 복잡해지고 소요되는 케이블양도 많아지고 있는 추세이다. 선박 전선 관리 시스템에서 가장 큰 비중을 차지하는 케이블 포설에 대한 케이블 최단 경로를 구하기 위하여 본 논문에서는 Dijkstra 알고리즘을 사용하였다. 본 논문에서 개발된 선박 전선 관리 시스템은 조선관련 선박 건조 시 비용 절감 및 업무 능률 향상을 통하여 회사의 경영 목표를 달성 할 수 있도록 지원해 줄 수 있는 시스템으로 사료된다.

• 대한토목학회논문집
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• 제28권1A호
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• pp.51-58
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• 2008

사장 케이블은 휨강성이 미소하여 휨변형에 관한 고유감쇠비가 매우 작다. 따라서 케이블 부재는 다른 구조부재보다 진동발생 가능성이 훨씬 높게 된다. 사장 케이블의 진동은 우수와 기류에 기인된 것과 지점운동에 기인된 것으로 대별된다. 특별히 보강형과 사장 케이블의 고유진동수 대역이 일치되는 경우를 제외하고 대부분은 우수와 기류에 기인된 진동이 발생된다. 이런 현상은 와류진동, 풍우진동, 갤로핑을 발생시키며 사장 케이블의 사용성과 내구성을 저하시킨다. 이에 대한 제어방안으로 추가감쇠비 부여(댐퍼도입)는 보편적이고 효과적인 것으로 알려져 있다. 하지만 국내는 케이블 지지교량이 활발하게 설계되고 시공됨에도 불구하고 주요 부재인 케이블의 동적설계에 관한 지침개발이 미진한 상황이다. 따라서 케이블 댐퍼도입에 관한 지침개발이 시급하다. 본 연구는 사장 케이블의 진동현상 중 댐퍼도입으로 효과적인 제어설계가 가능한 와류진동, 풍우진동, 갤로핑의 전체감쇠비 평가방법을 전개하여 풍현상에 따른 요구감쇠비 하한을 제시하고, 설치위치에 따른 유효계수가 고려된 추가감쇠비 상한과 최소설치위치를 제시하여 댐퍼도입에 의한 일관되고 체계적인 사장 케이블 제진설계 지침을 제안하고자 한다.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.586-590
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• 2011

This paper presents the case study of the CE by collaborative system and proposes a model of the CM group for the cable supported bridge. The cable supported bridges have a large project scale and need a high level of construction method. Therefore an advanced construction management system is required for successful completion of project. The construction management (CM) group which control design management, construction plan, subcontract, technical support and R&D is organized for the cable supported bridge project. The CM group established a collaborative system with construction site and drew an effective management of cost, process, quality, safety for each project. Furthermore, the CM group established the procedure of construction management based on the construction engineering (CE) items and performed the project management on the construction phase. Efficiency of cost reduction and site control is maximized by using a collaborative system.

• 한국산학기술학회논문지
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• 제20권2호
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• pp.632-637
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• 2019

해양 플랜트 전장생산설계의 케이블 트레이 설계는 구조 부재 및 각종 의장 장비들과 간섭없이 케이블이 설치될 수 있도록 3D 모델링하여 원활하게 최적 배치하는 작업으로, 대부분 PDMS(Plant design management system)를 이용하여 수행되고 있다. PDMS는 해양 플랜트 생산설계 전용 3D CAD 시스템으로 국내 조선소와 관련 설계협력업체에서 널리 사용되고 있다. 본 연구에서는 PDMS 기반 해양 플랜트 케이블 트레이 설계 지원 PML(Programmable macro language)을 개발하여, 기존 방법 대비 업무 효율성을 검토하였다. 개발된 케이블 트레이 설계 PML은 전장 템프릿 라이브러리를 이용하여 완전히 파라메트릭 설계가 가능하도록 함으로써 설계 변경으로 인한 빈번한 수정 작업에 신속히 대응할 있도록 하였고, 축적된 설계 경험를 반영하여 반복되는 작업 피로를 최소화할 수 있도록 하였다. 그리고 개발된 시스템을 해양 플랜트 구조 모듈에 적용하여 기존 방법 대비 약 50% 이상의 작업 효율성 향상이 예상됨을 확인하였다.

• 한국전자통신학회논문지
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• 제9권4호
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• pp.469-474
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• 2014

전신주에 설치된 난립 통신선로의 포설 상태를 모니터링하고, 정비용 부가정보 수단을 제공할 수 있는 현장 모니터링 지원 시스템을 개발한다. 공중선로 정비 지원을 위한 모니터링 모듈 및 정보 처리 어플리케이션을 적용 임베디드 시스템을 제작한다. 본 연구에서는 정부의 공중선 정비 종합계획에 따라 작업 안전사고 예방 지원 장치로 보급하기 위한 대도시 공중선 정비 사업에 즉시 활용하고, 고소 공사 편의 및 작업자의 정비 효율성을 제고하는데 목적을 둔다.

• Steel and Composite Structures
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• 제46권6호
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• pp.731-744
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• 2023

Vehicle load information is an important role in operating and ensuring the structural health of cable-stayed bridges. In this regard, an efficient and economic method is proposed for vehicle load detection based on the observed cable tension and vehicle position using a graph neural network (GNN). Datasets are first generated using the practical advanced analysis program (PAAP), a robust program for modeling and considering both geometric and material nonlinearities of bridge structures subjected to vehicle load with low computational costs. With the superiority of GNN, the proposed model is demonstrated to precisely capture complex nonlinear correlations between the input features and vehicle load in the output. Four popular machine learning methods including artificial neural network (ANN), decision tree (DT), random forest (RF), and support vector machines (SVM) are refereed in a comparison. A case study of a cable-stayed bridge with the typical truck is considered to evaluate the model's performance. The results demonstrate that the GNN-based model provides high accuracy and efficiency in prediction with satisfactory correlation coefficients, efficient determination values, and very small errors; and is a novel approach for vehicle load detection with the input data of the existing monitoring system.

• 한국해양공학회지
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• 제33권3호
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• pp.205-213
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• 2019

Recently, because of the global recession of the offshore plant industry and low-cost orders, there has been increasing interest in strengthening the competitiveness of domestic companies for the design and production technologies of offshore plants. However, in the offshore plant design field, the Plant Design Management System (PDMS), which is a 3D CAD program for plant layout developed by AVEVA Marine, is already commonly used as offshore plant design software and widely used in large domestic shipyards and cooperative design companies. Under this background, we have been thinking about ways to design better with the existing software. In this study, we developed a parametric design program to maximize the efficiency and reduce the working time for offshore plant electrical outfit production design based on the Programmable Macro Language (PML) of PDMS. We also examined its performance. By applying the developed program to the offshore plant module selected as an application example, it was confirmed that a 50% improvement in the work efficiency of cable tray design could be obtained compared with the existing method, with work efficiency improvements of 80% or more in other field design work.

• Structural Engineering and Mechanics
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• 제61권3호
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• pp.419-426
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• 2017

Recently, the transportation of dangerous explosive goods is increasing, which makes vehicle blasting accidents a potential threat for the safety of bridge structures. In addition, blasting accidents happen more easily when earthquake occurs. Excessive dynamic response of bridges under extreme loads may cause local member damage, serviceability issues, or even failure of the whole structure. In this paper, a new explosion-proof and aseismic system is proposed including cable support damping bearing and steel-fiber reinforced concrete based on the existing researches. Then, considering one 40m-span simply supported concrete T-bridge as the prototype, through scale model test and numerical simulation, the dynamic response of the bridge under three conditions including only earthquake, only blast load and the combination of the two extreme loads is obtained and the applicability of this explosion-proof and aseismic system is explored. Results of the study show that this explosion-proof and aseismic system has good adaptability to seism and blast load at different level. The reducing vibration isolation efficiency of cable support damping bearing is pretty high. Increasing cables does not affect the good shock-absorption performance of the original bearing. The new system is good at shock absorption and displacement limitation. It works well in reducing the vertical dynamic response of beam body, and could limit the relative displacement between main girder and capping beam in different orientation so as to solve the problem of beam falling. The study also shows that the enhancement of steel fibers in concrete could significantly improve the blast resistance of main beam. Results of this paper can be used in the process of antiknock design, and provide strong theoretical basis for comprehensive protection and support of girder bridges.