• 제목/요약/키워드: Roads

검색결과 2,323건 처리시간 0.03초

셀룰로오스 섬유보강 콘크리트를 사용한 기계화경작로 확·포장공사의 현장사례 연구 (Field Case Study of Mechanized Form Roads Pavement Construction using Cellulose Fiber Reinforced Concrete)

  • 박종건
    • 한국농공학회논문집
    • /
    • 제57권2호
    • /
    • pp.47-56
    • /
    • 2015
  • At the present, the mechanized form roads pavement was constructed with plain concrete. Mostly, it was used by welded wire mesh for preventing crack. Cellulose fibers for the reinforcement of concrete offer relatively high levels of elastic modulus, fiber count (per unit weight), specific surface, and bond strength to cement-based materials. The construction of concrete pavement confirmed that cellulose fiber reinforced concrete was applicable to mechanized form roads pavement. In the study, cellulose fibers were used here at 0.08 % volume fraction, which is equivalent to a fiber content of $1.2kg/m^3$. Cellulose fiber reinforced concrete were compared with plain concrete. Field test results indicated that cellulose fiber reinforced concrete showed slightly to increase of 28 days compressive strength and improved the initial strength. it tended to increase of splitting tensile strength. Test results showed that the slump and air content tend to decreased. but, the variation of air contends is very little. Also, construction cost of cellulose fiber reinforced concrete is less than about 25.7 % the case of welded wire mesh previously used. Therefore, The cost reduction is expected to be possible in construction site by mechanized form roads pavement.

추정된 타이어 힘을 이용한 능동 조향 제어 (Active steering Control Based on The Estimated Tire Forces)

  • 서찬원;김준영;홍대건;허건수
    • 대한기계학회논문집A
    • /
    • 제24권9호
    • /
    • pp.2228-2234
    • /
    • 2000
  • Steering of the vehicles on a slippery highway is a difficult task for most passenger car drivers. The steering vehicles on slippery roads tend to slide outward with less lateral forces than on nor mal roads. When the drivers notice that their vehicles on a slippery highway start to depart from the cornering lane, most of them make a sudden steering and/or braking, which in turn may induce spin-out and instability on their vehicles. In this paper, an active steering control method is proposed such that the vehicles in slippery roads are steered as if they are driven on the normal roads. In the proposed method, the estimated lateral forces acting on the steering tires are compared with the reference values and the difference is compensated by the active steering method. A fuzzy logic controller is designed for this purpose and evaluated on a steering Hardware-In-the-Loop Simulation (HILS) system. Steering performance results on the slippery curved and sinus roads demonstrate the effectiveness of the proposed controller. This method can be realized with the steer-by-wire concept and is promising as an active safety technology.

지방부 신호교차로 주·야간 교통사고 예측모형 개발 및 비교 분석 (Development of Traffic Accident Models at Rural Signalized Intersections by Day and Night)

  • 이근희;정상운;박민호;이동민;노정현
    • 한국도로학회논문집
    • /
    • 제17권3호
    • /
    • pp.107-115
    • /
    • 2015
  • PURPOSES : The purposes of this study are to compare the day and night characteristics and to develop the models of traffic accidents. in Rural Signalized Intersections METHODS : To develop day and night traffic accident models using the Negative Binomial Model, which was constructed for 156 signalized intersections of rural areas, through field investigations and casualty data from the National Police Agency. RESULTS : Among a total of 17 variances, the daytime traffic accident estimate models identified a total of 9 influence factors of traffic accidents. In the case of nighttime traffic accident models, 11 influence factors of traffic accidents were identified. CONCLUSIONS : By comparing the two models, it was determined that the number of main roads was an independent factor for daytime accidents. For nighttime accidents, several factors were independently involved, including the number of entrances to sub-roads, whether left turn lanes existed in major roads, the distances of pedestrian crossings to main roads and sub-roads, lighting facilities, and others. It was apparent that if the same situation arises, the probability of an accident occurring at night is higher than during the day because the speed of travel through intersections in rural areas is somewhat higher at night than during the day.

도로평가를 위한 인터넷 VR 시스템 구축 (The Construction of Internet Virtual Reality System For Highway Estimation)

  • 강인준;최현;한병철;이병걸
    • 한국측량학회:학술대회논문집
    • /
    • 한국측량학회 2004년도 추계학술발표회 논문집
    • /
    • pp.367-372
    • /
    • 2004
  • Highway have to be constructed under thorough investigation about function, economy, safety of the traffic and environment, because they are needing huge budget for construction and management as important facilities of the social overhead capital in the national economics. Initially the construction of roads becomes effective the plan, the design, construction phase. The design is foundation of accomplishment of the roads operation, the results of the design operation come to much effect a nation when using roads. Especially ancient design methods were not expected for visual effects as attaching weight to 2-dimensional drawing from flat. Therefore, it is difficult to recognize troubles happened during the work operation besides, many troubles are solved by modification of drawings as situations. For solving of those of the problems, it is emphasize on visual effect through introduction of 3-dimensional design from the initial phase. In case of national conditions, limited national land has caused increasing weight for construction of the roads through cities as the urban centered development. thereupon, citizens are increasing concern about the right of the light and the environmental effect, road designs and construction of the structures under agreement with local residents cause to make troubles. The analysis of 3-dimensional design is necessary as intermediation for decision making. In this study, Virtual reality techniques in 3-dimensional roads design are expected to visual effect on the publishing Internet Web, find problems in first phase and make decision between users and people having civil appeal.

  • PDF

제주시 원도심 골목공간의 특성에 관한 연구 - 시가지 재정비 제도를 중심으로 - (A Study on Characteristics of cul de sac Road in Old Settlements of Downtown Jeju - Focus on a Collaborative Development based on a neighborhood plan -)

  • 양건;이상호;이용규
    • 한국농촌건축학회논문집
    • /
    • 제17권2호
    • /
    • pp.1-8
    • /
    • 2015
  • The study is to find regional characteristics of the old town of Jeju city, "Mu-gun-sung," through researches of the status of the spatial structure in the cul de sac roads of the area. In particular, the status and characteristics of the area are clearly defined with the typology of the cul de sac roads based on the urban renewal regulations. The results are listed as follows: First, there are buildings from various periods in the area. Second, it is comparatively analyzed that there are the similarities and differences in Collaborative Development based on a neighborhood plan in Japan and Korea which pursue conservative renewals of the cule de sac roads. Third, the status and characteristics of the area are clarified through the analysis of the types of the cul de sac roads.

농어촌 도로의 정비현황 조사 분석 - 전남 군지역을 중심으로 - (Analysis on the Improvement Level of Minor Rural Roads - A Case Study on the Country Areas of Chonnam Province -)

  • 최수명;이행욱;최동진
    • 한국농공학회:학술대회논문집
    • /
    • 한국농공학회 2003년도 학술발표논문집
    • /
    • pp.119-122
    • /
    • 2003
  • This study was carried out to propose some useful advices for the improvement policy of the minor rural roads. From the case study on 5 country areas of Chonnam Province, it was ascertained that above a third of minor rural roads did not meet the statutory minimum level of their width, which means the necessity of substantial upgrade of road improvement works in rural areas.

  • PDF

주거단지내의 주거환경개선 방안에 관한 연구 - 이면도로 공간을 중심으로 - (A Study on the improvement of Residential Environment in Housing Area)

  • 김한수;송흥수
    • 한국주거학회논문집
    • /
    • 제8권3호
    • /
    • pp.197-207
    • /
    • 1997
  • This study is about the improvement of housing environment through the research and analysis on how district-level roads are used and what the residents want about housing environment. The results are as follows: 1. As a result of the research on space usage, we could get the conclusion that street furniture occupies much space in the district-level roads, and the main causes of the space usage problems are from cars. 2. Because much space is used for parking, the district-level roads supposed to be the place for the pleasant and safe housing is changing into the main cause of the housing problems. Therefore we should find how to prevent the housing environment from being deteriorated through pridicting the traffic generation of future residential area. 3. Most residents park their cars near their houses in the district-level roads. In order to solve this problem, we have to secure the parking space and guarantee the safe traffic by designing the road space efficiently in spite of the inconvenience.

  • PDF

도시녹지의 대기정화효과에 대한 분석적 연구 - 도시 가로수를 중심으로 - (An Analytical Study on the Air Purification Effect of Urban Openspace - Focusing on Urban Roadside Trees -)

  • 성현찬;문다미
    • 한국환경복원기술학회지
    • /
    • 제6권3호
    • /
    • pp.17-28
    • /
    • 2003
  • The objective of this study is to review and verify whether the functions and effect of roadside trees generally known in theory are actually realized in urban roads and how well they are performed if the function and effect are really realized. The study was conducted with a focus on air purification effect of roadside trees. The m헤r study result is as follows. First, calculation of air purification effect of roadside trees showed that it is minimal. However, 7.4 units of broad-leaved trees is necessary in order to purify $SO_2$ discharged by one passenger car and 1,803.3 trees to purify $NO_2$. Second, regarding pollutant absorption capacity, air pollutant absorption capacity increased as the number of rows planted gets higher (i.e., 2-row plantation absorbs pollutant better than I-row plantation). In particular, "2-row plantation + lower-level shrub + buffer green belt" was as eight times high as "I-row plantation" in absorption capacity. Third, out of 30 roads with over 8 lanes in 15 cities, only 33.3% or a total of ten roads in seven cities had a median strip. Out of these ten roads, nine roads were planted in a double-layer consisting forest trees, shrubs, ground plants (grass). Analysis showed that out of six tree species planted along these roads, about a half of them were weak to air pollution. Also, based on the outcome of this study, charging a "plantation due" when people purchase a new car, improving layout of roadside trees, and reinforcing plantation of air purification tree species when selecting tree species for roadside trees were proposed.

간선도로 기능별 교통사고모형 개발 - 청주시를 사례로 - (Developing the Traffic Accident Models by the Function of Arterial Link Sections in the Case of Cheongju)

  • 김진선;김태영;김경환;박병호
    • 한국도로학회논문집
    • /
    • 제13권1호
    • /
    • pp.49-57
    • /
    • 2011
  • 이 연구는 청주시의 가로구간 교통사고를 다루고 있다. 연구의 목적은 가로구간의 기능별 사고모형을 개발하는 데 있다. 이를 위해서 이 연구는 전체 472개의 세부구간으로 분리된 주간선도로와 보조간선도로의 사고 자료를 이용하여 적합한 모형을 개발하는데 중점을 두고 있다. 연구의 주요 결과는 다음과 같다. 첫째, 주간선과 보조간선도로의 사고특성에 대한 t 검정은 두 도로의 사고건수와 EPDO에 차이가 있는 것으로 나타나 기능별 사고모형 개발이 적절한 것으로 분석된다. 둘째, 주간선도로의 EPDO와 사고건수는 모두 ZINB모형이 적합한 것으로 분석된다. 셋째, 보조간선도로 EPDO는 ZINB모형, 그리고 사고건수는 ZIP모형이 최적인 것으로 분석된다. 마지막으로 주간선도로 사고모형(ZINB)의 공통변수는 교통량과 굴곡점수, 보조간선도로의 EPDO모형(ZINB)과 사고건수모형(ZIP) 공통변수는 평균종단경사인 것으로 평가된다.