• 제목/요약/키워드: Ground block

검색결과 306건 처리시간 0.023초

지하수댐 물막이벽 시공법과 해안지역 염수침입 방지기술 개선 방안 (The Study on Constructing Underground Wall to Prevent Seawater Intrusion on Coastal Areas)

  • 부성안;이기철;김진성;정교철;고양수
    • 지질공학
    • /
    • 제12권2호
    • /
    • pp.215-234
    • /
    • 2002
  • 지하수댐은 대용량의 지하수를 효과적으로 확보할 수 있는 시설로서 저류수는 유역조건과 대수층조건, 상류부 오염원 분포와 수질에 따라 상수도용, 중수도용, 농업용 또는 공업용 등으로 다양하게 이용할 수 있으므로 적절한 지하수범 설치 방법은 용수부족을 해결할 수 있는 주요 기술의 하나이다. 지하수법을 활성화시키기 위해서는 대수층 위치 및 지층에 맞는 적절한 차수공법의 선택과 정밀한 물막이벽 시공, 대수층 구조·수문·물수지 등의 정확한 분석, 장기적인 지하수 이용계획과 저류역내 수질보전대책 수립, 수위·수질에 대한 장기 모니터링 실시로 지속적인 유지관리, 지속가능한 대용량 취수기술에 대한 조속한 연구, 지하수댐 개발로 인한 주변환경에 미치는 영향에 대한 철저한 분석 및 대책 수립 등이 필요하다. 그리고 해안지역 지하수법에서 발생하는 염수침입 현상을 방지하는 방안으로 물막이벽을 이중으로 설치하는 방법이 있다.

3경간 연속 거더교의 지진응답에 대한 포트받침 노후화의 영향 (Effect of Pot Bearing Aging on the Seismic Response of a Three-span Continuous Girder Bridge)

  • 조주현;김동호;강준원;윤혜진
    • 한국전산구조공학회논문집
    • /
    • 제37권4호
    • /
    • pp.251-258
    • /
    • 2024
  • 이 논문은 포트 받침이 설치된 3경간 연속 콘크리트 거더교를 대상으로 받침의 노후화가 교량의 지진응답에 미치는 영향을 분석하였다. 포트 받침은 고정단 및 가동단의 강성을 반영해 교축방향, 교축직각방향, 수직방향의 탄성 스프링으로 모델링하였다. 포트 받침의 노후화를 고정단 받침의 수평강성 저하와 가동단 받침의 수평강성 증가로 나누어 받침의 노후화가 교량의 지진 거동에 미치는 영향을 분석하였다. 수치해석으로부터 구한 고유진동수 값과 이 교량의 설계 고유진동수를 비교하여 해석 대상 3경간 연속 거더교의 유한요소모델이 타당함을 보였으며, 국내 도로교설계기준(한계상태설계법)의 설계응답스펙트럼에 부합하는 인공지진파를 이용해 받침 강성의 변화에 따른 교량 상부 및 받침의 지진응답을 계산하였다. 지진해석 결과, 받침의 노후화로 인해 고정단 받침의 수평강성이 감소할 경우 지진으로 인한 고정단 받침의 절대최대 상대변위가 증가하였다. 이는 받침을 지지하는 모르타르의 균열과 앵커 볼트의 탈락 가능성이 커짐을 의미한다. 받침의 노후화로 인해 가동단 받침의 수평강성이 증가하는 경우에는 지진으로 인한 고정단 받침의 절대최대 전단력이 감소하였다. 그러나 이 경우 가동단 바로 위 거더 단면에 추가의 휨인장응력이 발생할 수 있으며, 이러한 받침 성능의 변화로 인하여 지진 시 연속 콘크리트교에 예기치 못한 구조적 손상이 발생할 수 있다.

Effects of Hybrid and Maturity on Maize Stover Ruminal Degradability in Cattle Fed Different Diets

  • Arias, S.;Di Marco, O.N.;Aello, M.S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제16권11호
    • /
    • pp.1619-1624
    • /
    • 2003
  • The effect of maize hybrid (Suco and Dekalb 765, DK 765), maturity stage (milk, $R_3$ and 1/2 milk line, $R_5$) and animal diet (Diet 1: 70% lucerne hay+30% maize silage; Diet 2: 50% maize silage+20% sunflower meal+30% maize grain) on ruminal stover dry matter (DM) degradability was studied. Additionally, morphological and chemical plant composition was evaluated. Fodder samples ground at 2 mm were incubated in three Holstein steers (400 kg body weight) using the in situ technique. Ruminal degradation kinetics was studied and the effective degradability (ED) was estimated for an assumed kp of 5%/h. The in situ data was analyzed in a complete randomized block design with the animals as blocks. Significant interactions between hybrid${\times}$diet and maturity${\times}$diet on kinetic digestion parameters were detected. In Diet 1, hybrids did not differ in degradable fraction, kd or ED, although a minor difference (p<0.05) in the soluble fraction was found (25.5 and 23.2% for Suco and DK 765, respectively). In Diet 2, the DK 765 had greater degradable fraction (p<0.001) but smaller (p<0.01) kd than Suco, without differences in the soluble fraction or in ED. Anticipating the harvest increased ED of stover from 37.5% in $R_5$ to 44.6% in $R_3$ (average values across hybrids and diets) due to the increase (p<0.001) in the soluble fraction ($R_5$: 22.6%, $R_3$: 28.8%). It is concluded that hybrids had similar stover in situ DM degradability and that soluble fraction represent the main proportion of degradable substrates. Advancing the date of harvesting may not improve the in situ DM degradability of whole maize plant silage since the increase in stover quality is counteracted by the depression in the grain-to-stover ratio. The diet of the animal consuming silage might not improve stover utilization either.

Effects of insect-resistant genetically modified rice (Bt-9) cultivation on non-target insect diversity

  • Oh, Sung-Dug;Lim, Myung-Ho;Lee, Bumkyu;Yun, Doh-Won;Sohn, Soo-In;Chang, Ancheol;Park, Soon Ki;Suh, Sang Jae
    • 농업과학연구
    • /
    • 제45권1호
    • /
    • pp.28-37
    • /
    • 2018
  • This study was done to develop environmental risk assessments and a biosafety guide for insect-resistant genetically modified rice at a LMO (Living Modified Organism) isolation field. In the LMO quarantine area of Kyungpook National University, the species diversities and population densities of non-target insects found on insect-resistant genetically modified rice (Bt-9) resistant to Cnaphalocrocis medinalis and on non-GM rices (Dongjin and Ilmi) were investigated. The Bt-9 event was therefore evaluated under field conditions to detect possible impacts on the above ground insects and spiders. The study compared transgenic rice and two non-GM reference rices, Ilmi and Dongjin, at Gunwi in Southern Korea in 2016. Each rice was grown on three $18m^2$ plots with a randomized block design. A total of 4,243 individuals from 43 families and 9 orders were collected from the LMO isolation field. In the three types of rice fields, a total of 1,467 individuals from the insect-resistant genetically modified rice (Bt-9), 1,423 individuals from the Ilmi, and 1,353 individuals from the Dongjin were collected, respectively. There was no difference between the population densities of the non-target insect pests, natural enemies and other insects on the insect-resistant genetically modified rice (Bt-9) and non-GM rices. These results provide the diversity and population density of non-target insects for an environment risk assessment survey on insect-resistant genetically modified rice and could be used as a guideline to make a biosafety assessment method for genetically modified crops.

인공산성우에 대한 조경수목의 내성 비교 (A Study on Resistant Comparisons of Landscape Trees by Simulated Acid Rain)

  • 정용문
    • 한국대기환경학회지
    • /
    • 제7권3호
    • /
    • pp.208-218
    • /
    • 1991
  • To compare the resistance of landscape trees by acid rain, simulated acid rain was treated on the seeds of 6 coniferous species (Pinus densiflora, Pinus thunbergii, Pinus koraiensis, Taxus cuspidata, Cedrus deodara, Thuja occidentalis) and 6 broad-leafed species (Ligustrum obtusifolium, Acer Buergerianum, Acer Ginnala, Styrax obassia, Cornus Kousa, Magnolia obovata). The experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agri-Tech Junior College. The seeds of 12 tree species were planted on the nursery soil in the early spring of 1991. The regime of artificial acid rain, in terms of spray frequency per monthly and spray amount at year records. Simulated acid rain (pH 2.0, pH 4.0, pH 5.6 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (April 8 to August 31) in 1991. Seedling establishment, seedling growth and nutrient contents in needles and leaves were measured and compared among the treatment. The results were summerized as follows; 1. In general, coniferous species were more resistant than broad-leafed species in the resistant comparisons of landscape trees by simulated acid rain. But there were resistant tree species to acid rain among the broad-leafed species. 2. Among 6 coniferous species used in this experiment, Pinus densiflora, Pinus koraiensis, Taxus cuspidata, Cedrus deodara and Pinus thunbergii revealed the resistant tree species to acid rain. But Thuja occidentalis was very susceptible to acid rain, because of no germination in pH 2.0 treatment plot of acid rain. 3. Among 6 broad-leafed species used in this study, Magnolia obovata, Styrax obassia and Ligustrum obtusifolium showed relative resistant tree species to acid rain. But Acer Buergerianum, Acer Ginnala and Cornus Kousa were very susceptible to acid rain, because of no germination in pH 2.0 plot of acid rain treatment.

  • PDF

양방향 말뚝재하시험(BD PLT)을 적용한 초고층 건축구조물의 기초설계 및 시공사례 (A Case Study of a Foundation Design and Construction of a High-rise Building Applying Bi-directional Pile Load Test(BD PLT))

  • 김성호;이민희;황근배;최용규
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2006년도 추계 학술발표회
    • /
    • pp.539-550
    • /
    • 2006
  • New Songdo city is currently developing on the reclaimed land on a marine deposit and among the development the four sixty-four(64) stories high rise buildings are under construction at block 125. The ground condition of the site is comprised of a deep seated weathered rock staratum under a soft marine deposit layer. As a foundation system, a bored pile was planned to transmit the applied load to the stable layer. In this study, the behavior of the weathered rock especially locating at a upper part having a weak strength(HWR, MWR) has been evaluated through series of hi-directional pile load test(BD PLT) carried out on the 3 drilled shafts socketed in a weathered rock layer in a design stage. It has been planned to increase the effect of the tests that the length of test piles was prepared short enough to perform the test under a high stress. The summary of the design reflecting the test results has been made up. In addition, the 4 hi-directional pile tests excuted on the working piles during the construction stage for the purpose of confirmation and the evaluation of the adequacy of the pile behaviors have been included in this study.

  • PDF

Effect of Graded Dietary Levels of Neem (Azadirachta indica) Seed Kernel Cake on Carcass Characteristics of Broiler Rabbits

  • Vasanthakumar, P.;Sharma, K.;Sastry, V.R.B.;Kumar, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제12권8호
    • /
    • pp.1246-1250
    • /
    • 1999
  • Rabbits (48) of Soviet chinchilla (24) and White giant (24) were fed from 6 weeks to 12 weeks of age intensively on either of four isonitrogenous - isocaloric diets containing 0 ($D_1$), 5($D_2$), 10($D_3$) and 20($D_4$) percent raw neem seed kernel cake (NSKC), respectively as per NRC (1977) requirements in a Randomized block design and slaughtered at the end to find out differences in their carcass traits due to NSKC feeding. Dietary treatment had no significant effect on weight of edibles and inedibles and their percentages and dressing percentage in terms of carcass, carcass with pluck and carcass with pluck and head. Similarly, the meat-bone ratio of various primal cuts and overall carcass, yield of edibles per unit of inedibles and eye muscle area were not influenced due to the dietary variations. Chemical composition of fresh meat, and organoleptic evaluation of cooked meat with and without salt did not vary significantly due to incorporation of NSKC in the diets. The rabbits fed 20% NSKC ($D_4$) though consumed more (p<0.05) DM and DE per kg meat production, the intake of crude protein and total digestible nutrients was similar with other dietary treatments. Feed cost per unit meat production was, however, lower on 5 and 10% NSKC containing diets by 7.75 and 12.56%, respectively, as compared to deoiled ground nut cake containing control diet. It appears that NSKC could be used as a wholesome vegetable protein supplement upto 10% in diet of rabbits without any adverse effect on commercial carcass traits.

ARIA 암호 알고리즘을 이용한 원격측정 시스템 암호화 기법 (Telemetry System Encryption Technique using ARIA Encryption Algorithm)

  • 최석훈;이남식;김복기
    • 한국항행학회논문지
    • /
    • 제24권2호
    • /
    • pp.134-141
    • /
    • 2020
  • 원격측정 시스템은 무인기, 위성 발사체 등의 비행체 개발과정에서 비행 데이터 수집과 모니터링을 위해 비행체 내 다양한 신호를 계측하여 지상으로 전송하는 통신시스템이다. 최근 무선통신 기술의 발전으로 비행 데이터의 전송 과정에서 일어날 수 있는 보안 위협에 대응하기 위해 원격측정 시스템의 암호화 기술 적용은 중요해지고 있다. 따라서 본 논문에서는 원격측정 시스템의 암호화 적용을 위해 국가 표준 암호 알고리즘인 ARIA-256의 적용 방법을 제안하고 구현하였다. 블록 오류 확산과 원격측정 프레임의 특성을 고려하여 CTR (counter) 모드를 응용하고, 위성통신 표준화 기구(CCSDS)에서 권장하는 리드솔로몬 코드를 적용할 수 있도록 프레임을 구성하여 암호화하였다. ARIA-256 알고리즘과 암호 프레임은 FPGA(filed programmable gate array)로 구현하였고 시뮬레이션과 하드웨어 검증 시스템을 통해 연속성 있는 프레임의 암호화를 확인하였다.

해상컨테이너를 이용한 대학생기숙사 거주 활용 계획 연구 - 암스테르담 대학생기숙사 키트보넨 사례를 중심으로 - (The Planning of Schematic Design for Student Housing Using Shipping Containers - Focused on the Student Housing of Keetwonen -)

  • 이종찬;강윤도;김병선
    • KIEAE Journal
    • /
    • 제14권6호
    • /
    • pp.59-64
    • /
    • 2014
  • The purpose of this study was suggested to establish of student housing by using shipping container. The research method are a study of shipping container and characteristics of student housing by using shipping container, compared typically student housing with student housing by using shipping container. Also there are planning though a case study of various planes and survey based on the student housing city in Amsterdam, Netherland, is called Keetwonen. It is a planning for housing unit to actual build at the part of land to devise master plan The 40FT(High Cube) Shipping Container housing unit are double occupancy room with toilet and balcony. The common areas are the kitchen, laundry facilities, conference room and lounge are available on the first floor with a lightweight steel frame construction method applied for obtain substantive utilization of the space. Considering into the type and scale of site shall be planning in the form of side corridor and central corridor, which is preferable to separate the interior space into two areas by a central corridor to secure personal privacy. Also, planning such as a separate exterior panel, color and landscape design to improve the external image of the container and block the solar radiation heat influx with a pitched roof. Allow 24 college students shall live at the site of Seongnae-dong, Gangdong-gu in Seoul, Korea (site area $330.9m^2$), including common facilities and a lounge with a building that has three stories above ground were established to build plans to target the actual land.

절리 암반내 그라우팅 설계 및 성과 판단을 위한 절리틈새 밀도 분포의 3차원 영상화 연구 (3D imaging of fracture aperture density distribution for the design and assessment of grouting works)

  • 김중열;김유성;남지연
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2004년도 춘계학술발표회
    • /
    • pp.113-120
    • /
    • 2004
  • Grouting works in fractured rocks have been performed to reinforce the underground and/or to block ground water flow at the foundation site of dam, bridge and so on. For the efficient grouting design, a prior knowledge of the fracture pattern of underground area to be grouted in very important. For the practical use, aperture sizes of open fractures that will be filled up with grouting materials will be kind of valuable information. Thus, the main purpose of this study is to develop a new technique (so called "GenFT") enable to form a three dimensional image of fracture aperture density distribution from Televiewer data. For this, the study is to focus on dealing with (1) estimating aperture size of each fracture automatically from Televiewer time image, (2) mapping extension of fracture planes on a given section, (3) evaluating aperture density distribution on the section by using both aperture size and fracture face mapping result of each fracture, (4) developing an algorithm that can transfer the previous results to any arbitrary(vertical and/or horizontal) section around the borehole. Since 3D imaging means "a strategy used to form an image of arbitrarily subdivided 2D sections with aperture density distribution", it will help avoid ambiguities of fracture pattern interpretation and hence will be of practical use not only for the design and assessment of grouting works but also for various engineering works. Examples of fields experiments are illustrated. It would seem that this technique might lead to reflecting future trend in underground survey.

  • PDF