본 연구는 교량의 상시계측자료인 고유진동수 및 고유모드를 기준으로 계측기반모델을 구성하고, 구조해석을 수행하여 교량 공용상태에서 사장케이블 장력평가를 수행하였다. 케이블 설치 위치에 따라 하중유형별 케이블 장력이 다르다는 것을 알 수 있다. 고정하중과 활하중에 의한 케이블 계측장력은 케이블 설치위치에 따라 차이가 크지 않으나 설계하중을 적용한 해석결과보다 큰 값을 나타낸다. 계측기반모델에 대한 케이블장력분포는, 설계모델에 대한 장력보다 크지만, 계측장력과 유사한 분포를 나타낸다. 그러므로 장기거동을 고려하여 사장교 케이블설계는 계측기반모델의 해석결과를 반영할 필요가 있다. 이를 위하여 많은 계측자료를 이용한 장기거동 분석연구가 요구된다.

본 연구에서는 기존 강재브레이스 내진보강법이 가지는 좌굴문제 등 단점을 극복할 수 있는 중 저층 철근콘크리트 건축물에 효과적으로 적용할 수 있는 새로운 내진보강법을 개발하였다. Carbon Fiber Composite Cable (CFCC)을 이용하여 건축물 골조 외부에 X자 형태로 내진보강을 실시하고, 상부 및 하부 보 양 단부에 CFCC X-브레이싱을 고정하기 위해서 평판 및 돌출형 나사식 접합으로 내진보강을 실시하는 내진보강법으로서, 반복하중 실험을 통하여 내진보강 효과를 규명하였다. 실험체는 비교용 비보강 골조, 평판형 및 돌출형 CFCC X-브레이싱 내진보강 골조 실험체 총 3개를 제작하였다. 실험결과, 본 연구에서 개발한 CFCC 내진보강법은 강도증진형 내진보강법으로 드러났으며, 기존 강재브레이스 보강법 대비 중량증가가 거의 없으며, 재료자체가 압축에 대한 좌굴이 없으며, 경량이므로 시공성이 매우 우수하고 중량 및 체적대비 우수한 강도가 발휘될 뿐만 아니라 특히, CFCC의 직경을 변경함으로서 내진보강 목적 (강도 보강량)에 대응하여 내진성능을 쉽게 변화시킬 수 있는 장점이 있다.

Construction of long span bridges is rapidly increasing, the criteria of impact load and study of stability for suspension bridge cables by rear-end collisions and crash of the vehicle, not at the moment is the actual situation. In this study, the main cable of suspension bridges was applied appropriate impact loads and analyzed the structural stability of the cable.

The suspension bridge’s main cable requires regular checks for the decrease on the axial forces of the cable band bolts. In this paper, basic concepts are presented for the approach on the management of cable band bolts in suspension bridges. In additions, the reasons for the decrease of axial forces are investigated with various aspects and some measurement methods for the axial forces are presented as well.

In robotic surgery, a surgeon checks only a surgical site of patient in the progress of surgery by vision and sound information. In order to solve this limited information, the haptic function is necessary. And haptic surgical robot is also necessary to design a haptic master device. The master device for laparoscope operation with cable-conduit was developed in previous research to give haptic function. It suggested a possibility of developing a master device by using the cable-conduit. However, it is very inconvenient to use. Therefore, this paper suggests a new mechanism design structure to solve the problems of the previous work by new forming a new master device. And it has proved that it’s usability is better than previous one. Furthermore it has also experimented and analyzed that a backlash of new master device is compensated by smooth backlash inverse algorithm.

인터넷 서비스, 초고속 인터넷망, 음성서비스, 영상서비스 등 동통신 케이블 관련 산업분야에서 다량의 유가 금속 및 합성고분자가 사용되어지며, 1980~2000년대에 이르기까지 관련 산업의 발전에 따라 사용량이 급증하였다. 이중 젤리 충진 케이블은 설치 작업중 훼손이나, 또는 접속 부분에 물이나 기타 이물질의 오염을 방지하기 위하여 다량 사용되었다. 하지만, 광통신 케이블 산업의 발달과 기존 동통신 케이블의 노화로 많은 양의 폐동통신 케이블이 발생하였고, 2008년 기중으로 국내에서만 연간 6,500톤 정도가 배출되는 실정이지만, 국내 젤리케이블 폐기물 현황을 보면 무분별한 소각으로 염화물의 불완전 연소에 의한 Dioxin등의 발암 물질 발생 및 매립으로 토양 오염 등이 문제 되어지고 있다. 연구분야에서는 이런 오염원을 줄이고 폐기물에 포함되어있는 다량의 유가금속등을 재활용하고자 여러 가지 연구개발이 진행되어지고 있는 실정이며, 본 연구에서는 열유체를 이용한 열분해 공정을 통하여 산업폐기물에 포함된 합성고분자를 안정적으로 제거하고 유가금속을 회수하고자 하였다.

In this study, several vibration characteristics of model bridge due to changes in cable tension are experimentally analyzed. In order to achieve the study, acceleration responses are measured from the model bridge for several cable tension case. The values of features extracted by frequency transform method are increased due to tension-loss.

The main purpose of this study is to develop the advanced structural health monitoring techniques of cable-supported bridges. The research and development about two main topics has been performed as follows: The vision-based cable monitoring technology using cable moving robot and The long-term displacement monitoring technology of bridge structures using Global Navigation Satellite System (GNSS). Therefore, the 100-m-length cable vibration test facility, was selected as the test bed.

In this study, an automated cable non-destructive test (NDT) system was proposed to monitor the steel cable. Magnetic Flux Leakage (MFL) method was applied for the cable inspection. A multi-channel MFL sensor head was fabricated using Hall sensors and permanent magnets. A wheel based Cable climbing robot was used to improve the accessibility to cable. In addition, remote data transmission and robot control were possible by applying the Wireless LAN communication. Finally, developed element techniques were integrated to MFL based Cable Climbing NDT system, and the field applicability of the integrated cable NDT system was verified through a field test.

Seismic capacities of the cable members of Incheon Bridge have been evaluated for the three different levels of earthquake motions, which are 1000-year-return-period(design basis level)), 2400-year-return-perioda and hypothetical maximum earthquake level(A=0.66), respectively. Both response spectrum method and time-history method were adopted for the analyses. The results showed that the cable members of Incheon Bridge has safe seismic capacity even under the maximum hypothetical earthquake which is more than three times higher magnitude of the design basis earthquake

A local stress is concentrated on a web contiguous to the anchorage blocks. Esp. in case of twin cable system in single plane, engineers should verify bearing capacity of the web. So, the engineering team has verified this phenomenon.

The impact factor of general road bridges is typically calculated according to Korea Highway Design Code(KHDC) or Design Guidelines For Cable-Supported Bridges in Korea. Above design codes define the impact factor as the function of span length or effective span length. But calculated impadt factors from this function are different to the measured values of long-span bridges such as cable-stayed bridge, suspension bridge. There are several methods to estimate the impact factor of cable supported bridges. In this study, the impact factor of cable-stayed bridges is estimated from dynamic load tests and compared to calculated values from the various design codes.

Multiple strand cable should be installed by special method to achieve equivalent tensile force to each strand. The research group has developed special jacking system and verified experimentally. As a result, difference is below 2% bet. theoretical and experimental values.

This study presents a technical overview of snow and ice accretion on cable-stayed bridges and suspension bridges. Specially, it focuses on measures against snow or ice falling into bridge decks. Many different types of de-icing and anti-icing are discussed in this paper.

In this study, measured data of cable-supported bridge’s thermal expansion and contraction were analyzed. To evaluate structural behaviors by temperature variations, measured data were compared with theoretical values by correlation analysis between thermal movements and temperatures. Additionally, the cumulative displacements were analyzed. Through the analysis of the results, the evaluation methods of cable-supported bridge's thermal expansion and contraction is suggested.

Steel cables are frequently used for various infrastructures. Especially the steel cables in long span bridges are critical members Damage at cable members can occur in the form of cross sectional loss caused by corrosion and fracture. Therefore, NDE of steel cable is needed to measure the cross-sectional damage. In this study, Total Magnetic Flux sensor system was applied to monitor the condition of cables. This system measures total magnetic flux to detect the loss of metallic cross section area(LMA) of steel cable. To verify the feasibility of this study, 2 types of steel bar were fabricated and their output values measured by the search coil in total flux sensor.