• 제목/요약/키워드: soil cutting

검색결과 343건 처리시간 0.026초

PAP옹벽에서 역해석을 이용한 사면보강 사례 연구 (A Case Study on Reinforcement of Slope in PAP Retaining Wall using Back Analysis)

  • 김장득;김용하
    • 지질공학
    • /
    • 제19권3호
    • /
    • pp.345-350
    • /
    • 2009
  • 경주-감포간 국도건설공사 중 양북터널의 종점부측은 산악지형으로 도로가 산지의 사면으로 통과하기 때문에 대절토 구간으로 이루어져 있다. 이 구간에 사면안정공법으로 PAP옹벽을 설치하였다. 옹벽을 설치한 후 6개월 정도가 지나면서부터 PAP옹벽의 앵커체 일부가 파단되었다. 즉시 계측기를 추가 배치하고 응급조치를 한 다음 지금까지의 계측기록으로 역해석을 실시하였다. 동시에 앵커체의 정착부를 확인하기 위한 지층조사와 앵커체의 이상여부를 확인하는 인장시험을 실시하였다. 역해석 결과 당초 설계에 적용한 토질정수의 90%를 적용함이 타당한 것으로 나타났다. 이를 근거로 재설계를 시행하였으며, 재설계의 결과는 당초 허용응력 306 kN이던 앵커체를 591 kN 및 784 kN의 앵커체로 교체하고, 정착부의 위치를 당초 11.0 m에서 23.0 m를 증가시켰다. 앵커체를 교체한 후 약 5개월 정도가 지난 지금까지의 계측 결과는 안정된 상태를 보여주고 있다. 이 사례는 대형사고로 이어질 수 있었던 사례를 신속하고 정확한 조치로 사면을 안정화시킨 사례이다.

팥배나무 이식식재 방법에 따른 가로수목의 탄소저장 연구 (A Study on Carbon Dioxide Absorption of Street Tree according to Transplantation Planting Methods for Sorbus alnifolia)

  • 박청인
    • 한국환경과학회지
    • /
    • 제24권2호
    • /
    • pp.253-260
    • /
    • 2015
  • Enlargement of street tree planting area is the proper and effective solution to reduce carbon dioxide. This solution bases on the ability of carbon storage and uptake by tree metabolism. However, the circumstance of road side has fatal disadvantages in tree metabolism such as growth and maturity because cutting and filling of roadsides cause unnatural soil composition. In this point, early rootage of street tree is the main factor of reducing carbon dioxide. This study aimed to find a appropriate transplantation planting method for sound and rapid rootage of street tree. For the study, Korean Mountain Ash(Sorbus alnifolia) were used for experimental groups. The groups were categorized by three groups such as trees produced on container with mulching treatment, trees produced in outdoor with mulching treatment, trees produced on container with weeding treatment. Each group consisted 10 trees with same size and transplanted in experimental site. Five months after transplanting, each group was estimated the biomass and carbon storage through a direct harvesting method. According to results of the study, the carbon storage of trees produced on container with mulching treatment is 42% more than trees produced in outdoor with mulching treatment. And the carbon storage of trees produced on container with mulching treatment is 19.5% more than trees produced on container with weeding treatment. These results may imply that transplantation of container produced tree with mulching treatment is the most rapid rootage among other groups. The weeding treatment is more effective than mulching treatment for rapid rootage of street trees.

원심모형실험을 위한 전기비저항 탐사 시스템 구축 (Development of Electrical Resistivity Survey System for Geotechnical Centrifuge Modeling)

  • 조형익;방은석;이명종;추연욱;김동수
    • 한국지반공학회논문집
    • /
    • 제30권10호
    • /
    • pp.19-31
    • /
    • 2014
  • 원심모형실험 중 지반모형의 상태 변화를 입체적으로 파악하기 위한 방법으로 전기비저항 탐사를 시도하였다. 탐사 시스템은 현장에서 널리 사용되는 검증된 상용 장비를 바탕으로 하였다. 컴퓨터 원격 조정으로 실험 시설 내에 설치된 탐사 장비를 통제하고 실시간 해석을 통해 결과 영상을 원심 모형실험 중에 바로 확인할 수 있도록 구성하였다. 구축된 탐사 시스템의 안정적 구동 여부를 점검하기 위해 불포화상태로 조성된 모형 지반 상단에 염수를 떨어뜨려 지반 내부로 이동하게 하고 전기비저항 탐사를 수행하였다. 10g로 원심력을 가한 상태에서 실험을 수행하고 시간대별 염수 침투상황을 전기비저항 영상으로 확인하였으며 일반 중력장에서 동일하게 실험한 결과와 비교하였다. 실험 종료 뒤 모형지반 수직 절단면을 이용하여 직접 측정한 전기비저항 값과 획득한 영상을 비교함으로써 신뢰성을 검증하였다.

시간경과에 따른 임도 절토비탈면의 식생피복도 변화 (Changing of Vegetation Coverage through Elapsed Years on Cutting Slope in Forest Roads)

  • 전권석;마호섭
    • 한국환경복원기술학회지
    • /
    • 제7권3호
    • /
    • pp.14-25
    • /
    • 2004
  • The purpose of this study was investigated to the change of vegetation coverage by elapsed years on the cut slope of forest road in Jinju-si. The results obtained could be summarized as follows; The plant coverage on the cut slope of forest road was decreased hastily in first and second year after seeding. The plant coverage on the cut slope of forest road was increased as growth of seed-sprayed from third year. But the plants were began to competition with between sprayed seeds and invaded plants from third to fifth year after seed-spray. The numbers of invading plants were gradually increased as 581 individuals from sixth year after seed-spray. The cut slopes of the forest roads turned to a good site condition for growing of invasion plants. And also the total coverage on cut slope of forest roads by invading of surrounding plants was increased more. It showed that plant invasion on cut-slopes of forest roads would be mostly influenced by surrounding plants. The number of surrounding plants on the cut-slopes of forest roads was 59 species, and the number of invading plants showed 65 species. The invading species were high in order of Boehmeria tricuspis, Oplismens undulatifolius, Miscanthus sinensis var. purpurascens, Erechtites hieracifolia and Artemisia princeps var. Orientalis In the stepwise regression analysis, main factors affecting the coverage of vegetation on the cut-slopes of forest road showed in order of elapsed years, gravel contents(30~50%), middle, sandy loam, sandy clay-loam, soil hardness, aspect(NS), concave(凹) type and gravel contents(15~30%).

Anaysis of Fe in Seepage Water and Precipitates around a Hydrothermal Alteration Zone

  • Yun, Hyun-Seok;Moon, Seong-Woo;Lee, Jin-Kook;Jeong, Gyo-Cheol;Seo, Yong-Seok
    • 지질공학
    • /
    • 제27권3호
    • /
    • pp.345-351
    • /
    • 2017
  • Acid drainage in civil engineering structures such as tunnels may lead to the deposition of precipitates that clog drainage channels and pipework. In evaluating acid drainage, the Fe content of water and precipitates, indicated by reddish brown coloration of rock surfaces, rivers, and soils, may be an important factor. In this study, acid drainage was evaluated by analyzing the Fe content of reddish brown seepage water that occurred in part of a tunnel. Geological investigations around the tunnel revealed a hydrothermal alteration zone cutting the bedrock, and cropping out in the upper parts of the tunnel. Analysis of drillcore revealed many fracture zones and veins. Inductively coupled plasma spectrophotometric analyses of water, precipitates, and soil samples, collected in the seepage water zone and around the tunnel, were conducted to evaluate acid drainage. The Fe content of seepage water in the tunnel was 0.030-0.333 mg/kg, which is 2-22 times higher than in local groundwater. The Fe content of precipitates in the tunnel was 165,403-301,051 mg/kg, similar to the 206,167-422,964 mg/kg content of drillcore from the hydrothermal alteration zone located above the tunnel. It is concluded that the seepage water is derived from Fe-containing acid drainage flowing in perforated tunnel drainpipes along the fracture zones and veins around the hydrothermal alteration zone.

Structure and action mechanism of humic substances for plant stimulations

  • Jeon, Jong-Rok;Yoon, Ho Young;Shin, Gyeong-Im;Jeong, Song Yi;Cha, Joon-Yung;Kim, Woe-Yeon
    • 한국초지조사료학회지
    • /
    • 제38권3호
    • /
    • pp.175-179
    • /
    • 2018
  • Humic substances that can be obtained from coal resources such as leonardite in a bulk scale have been employed as crop stimulators and soil conditioners. The polymeric organics containing a variety of aromatic and aliphatic structures are known to activate plants in a multifunctional way, thus resulting in enhanced germination rate and abiotic stress resistance concomitant with induction of numerous genes and proteins. Although detailed structural-functional relationship of humic substances for plant stimulations has not been deciphered yet, cutting-edge analytical tools have unraveled critical features of humic architectures that could be linked to the action mechanisms of their plant stimulations. In this review article, we introduce key findings of humic structures and related biological functions that boost plant growth and abiotic stress resistance. Oxygen-based functional groups and plant hormone-like structures combined with labile and recalcitrant carbon backbones are believed to be critical moieties to induce plant stimulations. Some proteins such as HIGH-AFFINITY $K^+$ TRANSPORTER 1, phospholipase A2 and $H^+$-ATPase have been also recognized as key players that could be critically involved in humic substance-driven changes in plant physiology.

개착식 터널에서 파형강판 라이닝의 해석 기법 평가 (Evaluation of Analysis Code of Corrugated Steel Plate Lining in Cut-and-Cover Tunnel)

  • 김정호;김낙영;이용준;이승호;황영철;조철신;정형식
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
    • /
    • pp.1316-1323
    • /
    • 2005
  • Most tunnel lining material which has been used in the domestic is a concrete. But many problems as the construction period, the cost, and the crack occurrence for the design, construction, and management were happened in the concrete lining. For this reason, many research institutes like the Korea Highway Corporation recognize the necessity of an alternate material development and grow on the interest for that. So in this study, the behaviour characteristics for the application of the Corrugated Steel Plate Lining in cut-and-cover tunnel are evaluated as several conditions for the backfill height, the cutting slope, and the relative density of backfill soil are changed. In addition, through using that conditions, CHBDC(2000, Canadian Highway Bridge Design Code) is evaluated if it could be applied to the design by comparing with the numerical analysis results. As the behaviour characteristics of the Corrugated Steel Plate Lining by CHBDC and the static numerical analysis are analyzed, both the methods show the same linear increases of the compressive stress according to the increase of the backfill height. The CHBDC of the dead load condition has very similar tendency by comparing with the result of the static numerical analysis.

  • PDF

Indigenous Plant Utilization and Farming System of Garo Tribe in North-East Bangladesh: a Means of Sustainable Biodiversity Conservation

  • Rahman, Md. Habibur;Fardusi, Most. Jannatul
    • Journal of Forest and Environmental Science
    • /
    • 제28권2호
    • /
    • pp.84-96
    • /
    • 2012
  • A special type of indigenous knowledge on plants utilization and farming system was explored by the Garo tribe community in the North-East region of Bangladesh, which correspond to the severe dependence on homestead forest. Results show that the Garo are totally dependent on the natural resources and that the extent of their dependency is faithfully reflected in their ethno-botanical knowledge. Dependencies that the study addressed focused on various aspects of food, fruit, energy, timber and health care on plants products. Garo tribe community in Bangladesh followed agrosilvipastoral system in their homesteads. They have indigenous hunting procedure to trap the animal in the forest. A total of 9 foods, 15 fruits, 12 energy-producing and 11 timber species was found and recorded that the Garo used in their daily life. Moreover, Garo used 23 medicinal plants species and have vast indigenous knowledge about using herbal medicine in daily health care practices. The Garo women do mostly the household activities, managing homestead forest and helping agricultural field where men perform all hard working activities like ploughing, cutting trees, digging the soil, preparation of horticultural and agricultural land, hunting, etc. The overall quality of life of the Garo could be considerably upgraded if ethno-botanical issues and their own indigenous knowledge will complement with scientific knowledge. The findings of the study conclude that the conservation of the indigenous knowledge of the Garo tribe related to plants utilization can also be turned to good account in forest conservation and is an important tool in this tribal area of Bangladesh.

직금·자수에 사용된 금사의 형태와 특징 비교 고찰 (Study on the Form and Character of Gold Thread in Weave with Supplementary Gold Wefts·Embroidery)

  • 심연옥;이선용
    • 복식
    • /
    • 제63권7호
    • /
    • pp.79-93
    • /
    • 2013
  • In the Korean literature, records of systematic gold thread manufacturing such as gold foil(金 箔匠), gold foil bonded with fabrics(付金匠), gold foil bonded with paper materials(金箋紙匠), refining gold(鍊金匠), cutting gold(裁金匠), and making gold thread(絲金匠) can be easily found. We can infer from these literatures that the Korean people used to make gold threads. However, is not existent the gold thread making technique. Thus, a research was done using 67 pieces of gold thread artifacts used in textiles craft of Korea, China and Japan. The purpose of this research was to identify the characteristics of the Korean gold thread by studying the artifacts' form classification, gold foil, glue and the base. First, gold thread is divided into flat gold thread and wrapped gold thread. Wrapped gold thread was made in more various methods such as with a paper on the flat gold thread, metal thread and wrapped gold thread with gold foil on top. Compared to the flat gold thread, wrapped gold thread uses a thread that has a thinner and wider. Through this analysis, even making of the base of the gold threads was different according to the type. Secondly, we looked into the characteristics of materials according to form structure of the gold thread. After analysis of experiment results, we could know that to attach Korean gold thread, glue and the mixture of materials such as Red soil(朱土) was also added. The kinds of the base of gold threads were identified as paper, leather and intestines. Among those materials, for paper, Korea's Dakji, China's Sangpiji(桑皮紙) and Jukji(竹紙) and Japan's Anpiji(雁皮紙) seemed to have all been used, so because of the difference among countries, we can prove that Korea has also produced gold thread. By looking at the research, the base of gold threads and making features hugely vary according to the area.

잔디종자의 발아촉진에 관한 연구 (Studies on the method for promoting the germination of sod seed)

  • 조재영;김봉구
    • 한국작물학회지
    • /
    • 제4권1호
    • /
    • pp.125-129
    • /
    • 1968
  • 수확후 시일이 오래 경과되지 않은 금잔디종자의 발아촉진에 관하여 실험한 결과를 요약하면 다음과 같다. (1) 종자를 흡수시켜서 0~$2^{\circ}C$에 2~30일 냉장하는 것은 발아조장효과가 가장 현저하였다. (2) 종자를 농유산에 넣고 유리막대로 잘 교반하며 1분 30쯤 경과한 다음 수세 파종하는것도 발아조장의 효과가 컸다. 그러나 처리가 지나쳐서 종자가 흑별할 저오닥 되면 도리어 해롭다. (3) 잔디종자의 발아는 광선이 투입될 경우에 조장되며 복토는 발아를 감퇴시킨다. (4) 혼사종피마상 및 선부절제도 약간의 발아조장효과가 있는 것 같다. (5) 지벨레린, $NH_4$ $NO_3$, NAA 등의 처리는 발아조장효과가 거의 인정되지 않았다.

  • PDF