• 한국방재학회:학술대회논문집
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• 한국방재학회 2011년도 정기 학술발표대회
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• pp.166-166
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• 2011

한국건설기술연구원내에 세계 최초로 UHPC(초고성능 콘크리트)를 활용한 보도사장교를 설계 및 시공하여 공용중이다. 초고성능 콘크리트(UHPC, Ultra High Performance Concrete)는 기존의 콘크리트의 단점을 극복하기 위하여 강섬유 및 혼화재료를 사용하여 고강도화와 더불어 인장강도, 휨강도, 균열에 대한 저항성, 전단강도 및 내충격성을 대폭 개선시켜서 구조부재의 연성 및 강도를 확보하기 위해 개발된 것으로서 한국건설기술연구원이 독자적 연구를 바탕으로 UHPC를 개발하였고, KICT-UHPC의 특성을 충분히 반영한 보도사장교를 한국건설기술원내에 실구조물로 시공하였다. 한국건설기술연구원내 본관 1, 2동 연결 보도사장교(SUPER BRIDGE 1)의 진동실험을 통해 UHPC 보도사장교의 동특성(고유진동수 및 모드형상)을 평가하였다. 대상교량에는 보도사장교의 캔틸레버 구조 특성에 의해 발생하는 진동을 제어하기 위한 질량 264kg의 난간형 수직진동제어장치(TMD) 4대가 설치되어 있으며, 부가질량의 운동을 기계적으로 구속하거나 구속을 해제하여 TMD의 작동을 켜거나 끌 수 있도록 되어있다. TMD의 가동 및 정지시 동특성을 비교하는 정밀한 검증 실험을 통하여 TMD 설치에 의한 동특성의 변화도 평가하였다. 가진망치에 의한 충격실험으로부터 획득한 가속도 시간이력 데이터와 가진망치의 가진력 시간이력 데이터를 사용하여 주파수응답함수(FRF, frequency response function)를 계산하고, 이로부터 Super Bridge I의 동적모드형상과 고유진동수를 추출하였다. 1차 모드의 고유진동수는 TMD 정지시 2.2949 Hz, TMD 작동시 2.0996 Hz로서 8%정도 감소하였다. 충격해머에 의한 가진 실험을 통해 세계 최초로 시공한 UHPC 보도사장교의 진동특성과 관련한 신뢰성 있는 자료를 확보할 수 있었다.

• Smart Structures and Systems
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• 제22권1호
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• pp.95-103
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• 2018

Active vibration control via inertial mass actuators has been shown as an effective tool to significantly reduce human-induced vertical vibrations, allowing structures to satisfy vibration serviceability limits. However, a lot of practical obstacles have to be solved before experimental implementations. This has motivated simple control techniques, such as direct velocity feedback control (DVFC), which is implemented in practice by integrating the signal of an accelerometer with a band-pass filter working as a lossy integrator. This work provides practical guidelines for the tuning of DVFC considering the damping performance, inertial mass actuator limitations, such as stroke and force saturation, as well as the stability margins of the closed-loop system. Experimental results on a full scale steel-concrete composite structure (behaves similar to a footbridge) with adjustable span are reported to illustrate the main conclusions of this work.

• 한국공간구조학회논문집
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• 제4권2호
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• pp.107-115
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• 2004

보도육교의 목적과 의미는 매우 다양해 질 수 있다. 현대교량은 지역을 연결한다는 단순기능외에도 주위환경을 고려한 기능적 미적, 기술적 고려사항들을 담고 있다. 이러한 다각적인 교량의 역할을 가능하게 하는 설계개념을 모색하였다. 그리고 이들 다양한 설계개념을 교량에 반영하는 방식을 고찰하기 위하여 해외 창의적인 교량의 사례들을 살펴보았다.

• Structural Monitoring and Maintenance
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• 제1권1호
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• pp.89-110
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• 2014

Structural Health Monitoring (SHM) is an effective alternative to conventional inspections which are time-consuming and subjective. SHM can detect damage early and reduce maintenance cost and thereby help reduce the likelihood of catastrophic structural events to infrastructure such as bridges. After reviewing the Damage Index Method (DIM), an Iterative Damage Index Method (IDIM) is proposed to improve the accuracy of damage detection. These two damage detection techniques are compared based on damage on two structures, a simply supported beam and a pedestrian bridge. Compared to the traditional damage detection algorithm, the proposed IDIM is shown to be less arbitrary and more accurate.

• 대한토목학회논문집
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• 제3권3호
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• pp.27-37
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• 1983

본(本) 연구(硏究)는 경기도(京畿道) 설계심의회(設計審議會)에서 천마산(天馬山) 청소년(靑少年) 심신수련장(心身修練場) 현수교(懸垂橋) 설계심의시(設計審議時) 현수교(懸垂橋)의 동적(動的) 거동(擧動)에 대한 설계미비(設計未備)의 원인(原因)이 아직도 체계화(體系化)되지 못한 우리 나라 현수교(懸垂橋)의 설계자료(設計資料)와 지침(指針)의 불비(不備)함에 그 동기(動機)를 얻어, 유한요소법(有限要素法)을 적용(適用)하여 현수교(懸垂橋)의 비틀림진동(振動)에 대한 고유진동수(固有振動數)와 이에 상응(相應)하는 고유진동형(固有振動形)을 구(求)하였다. 실제(實際)로 현수교(懸垂橋)의 일반적(一般的) 거동(擧動)은 수직(垂直) 수평면(水平面) 내(內)에서의 연성(連成)된 운동(運動)으로 표시(表示)되지만 사용목적(使用目的)에 부합(附合)하여 그 진폭(振幅)을 미소(微小)하도록 제한(制限)하면 수직(垂直) 비틀림 진동(振動)은 단독(單獨)으로 비연성화(非連成化)할 수 있으며, 이에 따라 해석하였다. 1973년 6월에 개통된 Streamlined Box-Girder Type인 남해대교(南海大橋)와 Lateral Bracing으로 이루어진 단경간의 천마산(天馬山)의 현수교(懸垂橋)의 설계자료(設計資料)를 이용하여 수치해(數値解)를 얻었으며, 천마산(天馬山) 현수교(懸垂橋)의 경우(境遇) 보조(補助) 보강(補强)케이블의 유무(有無)에 따른 고유진동수(固有振動數)와 진동형(振動形)을 구(求)하여 비교(比較) 검토(檢討)하였다. 보강(補强)케이블의 유무(有無)에 따라 초기의 진동수(振動數) 등에서는 그 영향이 매우 뚜렷하였으나, 진동형(振動形)이 복잡해짐에 따라 보강(補强)케이블의 영향은 미약했거나 또는 오히려 역효과를 가져왔다. 남해대교(南海大橋)에 있어서 유한요소기법(有限要素技法)과 전자계산기에 의해 본(本) 연구(硏究)에서 구한 고유진동수(固有振動數)와 남해대교(南海大橋) 건설지(建設誌)에 있는 Frequency Equation으로 구한 값 또는 풍동실험(風洞實驗)에 의한 결과(結果) 등과 비교(比較) 검토(檢討)하였으며, 비교(比較) 결과(結果) 좋은 일치(一致)를 보여주었다.

• 자원환경지질
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• 제38권3호
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• pp.247-260
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• 2005

회동저수지 집수분지 내 주요 도로변 퇴적물의 중금속 함량은 토양오염 우려기준보다 낮게 나타났다 중금속함량이 높은 지역은 대부분 교통량이 많은 7번 국도이며 , 특히, 커브지점, 우수관, 과속단속 지점, 횡단보도 등에서 높은 함량을 보인다. 도로변 퇴적물 내 입도별 중금속 함량은 세립 입도($63{\mu}m$이하)일수록 높은 값을 보여주고 있으나, 총 함량은 조립 입도의 퇴적물($100{\mu}m$이상)에 의해 결정된다. 이는 우기 시에 유출수에 의해 세립 퇴적물이 주변 수계로 이동된 결과로 해석되며 수영강 및 회동저수지의 수질에 악영향을 미칠 수 있다. 따라서 교통량이 많은 7번 국도와 퇴적물이 쉽게 주변 수계로 유입될 수 있는 한물교와 같은 교량에서 퇴적물의 이동을 조절할 수 있는 적절한 처리시설이 요구된다.

• Smart Structures and Systems
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• 제6권9호
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• pp.1025-1039
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• 2010

Measuring displacement response for civil structures is very important for assessing their performance, safety and integrity. Recently, video-based techniques that utilize low-cost high-resolution digital cameras have been developed for such an application. These techniques however have relatively low sampling frequency and the results are usually contaminated with noises. In this study, an integrated visual-inertial measurement method that combines a monocular videogrammetric displacement measurement technique and a collocated accelerometer is proposed for displacement and velocity measurement of civil engineering structures. The monocular videogrammetric technique extracts three-dimensional translation and rotation of a planar target from an image sequence recorded by one camera. The obtained displacement is then fused with acceleration measured from a collocated accelerometer using a multi-rate Kalman filter with smoothing technique. This data fusion not only can improve the accuracy and the frequency bandwidth of displacement measurement but also provide estimate for velocity. The proposed measurement technique is illustrated by a shake table test and a pedestrian bridge test. Results show that the fusion of displacement and acceleration can mitigate their respective limitations and produce more accurate displacement and velocity responses with a broader frequency bandwidth.

• Advances in Computational Design
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• 제6권1호
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• pp.55-75
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• 2021

The lightweight superstructure is beneficial for bridges in remote areas and emergency erection. In such weight-sensitive applications, the combination of fiber-reinforced polymer (FRP) as a material and box-beams as a structural system have enormous scope. This combination offers various advantages, but as a thin-walled structure, their designs are often governed by buckling criteria. FRP box-beams lose their stability either by flange or web buckling mode. In this paper, the web buckling behavior of simply supported FRP box-beam subjected to transverse load has been studied by modeling full box-beam to consider the effect of real state of stress (stress variation in length direction) and boundary conditions (rotational restraint at web-flange junction). A parametric study by varying the sectional geometry and fiber orientation is carried out by using ANSYS software. The accuracy of the FE models was ensured by verifying them against the available results provided in the literature. With the help of developed database the influential parameters (i.e., αs, βw, δw and γ) affecting the web bucklings are identified. Design trends have been developed which will be helpful to the designers in the preliminary stage. Finally, the importance of governing parameters and design trends are demonstrated through pedestrian bridge design.

• 한국조경학회지
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• 제30권2호
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• pp.70-78
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• 2002

The landscape disign of Gamcheon wholesale fish Market was designed around a turnkey base to promote the economy of Busan Metropolitan City, to establish a fishery marketing center and to modernize existing facilities. The objectives of the project were to promote the mood of an old market, while preserving its functions and efficiency as a market, to design outdoor spaces with natural resources and amenities in balance, and to create attractive tourist spots in connection with the wide area development plan. The project was oriented, fast, to enhance the functions of the market. For this purpose, a multi-dimensional space layout was designed in consideration of functions as a wholesale market. The safety of pedestrians was secured by separating lathes for vehicles and for pedestrians. Tree planting with various functions such as sheltering, wind breaking and guiding was planned. Secondly, nature-friendly and human-friendly landscaping design was attempted. For this, the beautiful natural resources of Amnam Park were utilized, and green spaces such as green bridges linking buildings in the wholesale market, and rooftop gardens were to be arranged. In addition, environment-friendly facilities such as roads paved with natural materials(i.e. gravel, shells) and program parking lots were to be planned. Thirdly, landscape design was considered to create attractive tourist spots. For example, a fish farm was created as a theme street for pedestrians and various water-friendly spaces such as pedestrian ramps, observatories and seaside streets were to be secured. The main contents are as follows. First, a green bridge to Ahnnam Park was introduced for a tour source and flower garden, an event plan and viewing deck open to the sea were planned on the bridge's axis. Secondly, for the effective land use plan concerning open space and convenience to visitors, a promenade was planned, which is connected with the theme plaza and small plazas by environmental sculptures in front of the market hall and at the gate. As well, an observatory and a roof garden help create three dimensional multi leveled space, with a good view of the natural landscape of the sea, sky and park Thirdly, landscape materials, such as trees and those for facilities, strengthened for protection against the seawind and salt damage were selected. The commercial market area was intended to be transformed a traditional functional area of efficiency and economy into an attractive marine leisure area where both tourists and neighbors can make use of it.

• 한국조경학회지
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• 제30권1호
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• pp.52-60
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• 2002

This paper presents a streetscape design for "Dangiae-Gil"which is located at 126-1 Yangpyung-2dong, Yeongdeungpo-gu, Seoul and is about 500m in length and about 24m in width. The design goals are to make a green street on which people want to walk and people can walk and rest safely and pleasantly. To achieve these goals, concepts of environmentally-friendliness, placeness, safety, amenity, vitality, connectivity, and democracy are developed. For pedestrian safety, shared street concepts, such as crank, slalom etc. are adopted. The site is divided into 5 thematic spaces, such as "Village Entrance Space", "Culture Street", "Dangsan Park", "Nature Street", and "Ferry Space". The Village Entrance Space, which is an entrance of the Dangjae-Gil and a welcoming space, is for communicating information about the area. "Dangnamu"(zelkova tree) and signs are introduced here. The Culture Street is for experiencing past and present culture of the area. Colored tiles and plant boxes attached to benches are introduced. The Dangsan park is a sacred space where modem people can feel the sacredness of nature arid of being in a refuge. Dangjib, Dangnamu, multi-purpose plaza, athletic facilities, and playground for infants are introduced. The Nature Street is a space for feeling and teaming nature which has disappeared from the area leading to the river and a space for community participation. The elementary school walls were demolished and nature education spaces, such as butterfly and dragonfly garden, ecological pond, wildflower garden, etc., which are related to school education, are introduced. The Ferry Space is a space symbolizing a old ferry crossing and an entrance plaza to a bridge for "Sunyu-do\" . A boat-shaped deck, an elevator for handicap people, and parking space are introduced. In conclusion, sustainable management schemes for the site are suggested.sted.