• 제목/요약/키워드: Poor drainage

검색결과 159건 처리시간 0.025초

Field instrumentation and settlement prediction of ground treated with straight-line vacuum preloading

  • Lei, Huayang;Feng, Shuangxi;Wang, Lei;Jin, Yawei
    • Geomechanics and Engineering
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    • 제19권5호
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    • pp.447-462
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    • 2019
  • The vacuum preloading method has been used in many countries for ground improvement and land reclamation works. A sand cushion is required as a horizontal drainage channel for conventional vacuum preloading. In terms of the dredged-fill foundation soil, the treatment effect of the conventional vacuum preloading method is poor, particularly in Tianjin, China, where a shortage of sand exists. To solve this problem, straight-line vacuum preloading without sand is widely adopted in engineering practice to improve the foundation soil. Based on the engineering properties of dredged fill in Lingang City, Tianjin, this paper presents field instrumentation in five sections and analyzes the effect of a prefabricated vertical drain (PVD) layout and a vacuum pumping method on the soft soil ground treatment. Through the arrangement of pore water pressure gauges, settlement marks and vane shear tests, the settlement, pore water pressure and subsoil bearing capacity are analyzed to evaluate the effect of the ground treatment. This study demonstrates that straight-line vacuum preloading without sand can be suitable for areas with a high water content. Furthermore, the consolidation settlement and consolidation degree system is developed based on the grey model to predict the consolidation settlement and consolidation degree under vacuum preloading; the validity of the system is also verified.

급성 화농성 심낭염의 임상적 관찰: 5예 (Clinical Observation of Acute Suppurative Pericarditis: 5 Cases)

  • 마중성
    • Journal of Chest Surgery
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    • 제7권1호
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    • pp.79-84
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    • 1974
  • Acute suppurative pericarditis is recognized as a rare disease since development of antibiotics but therapeutically as an important one. To our knowledge, acute suppurative pericarditis alone has not been reported previously in Korea. In this paper, we report 5 cases of acute suppurative pericarditis which were experienced during the period between January 1959 and December 1973. The patients ranged in age from 9 months to 59 years at the time of admission. Four of 5 patients were male and one female. Acute suppurative pericarditis is usually associated with pneumonia, empyema, sepsis, osteoarthritis, lung abscess, cholecystitis or tonsillitis. In our series, pneumonia was the most common associated disease. One patient had osteoarthritis. Pleural effusions were observed in three of the 5 patients. Staphylococcus aureus was cultured from pericardial fluid in 4 patients and also cultured from both pericardial and synovial fluid in one. Three of the 5 patients had cardiac tamponade and one patient required prompt pericardiocentesis. 3 of the 5 patients were treated with antibiotics and pericardiostomy, one with antibiotics and pericardiocentesis, and one with antibiotics and saline irrigation through drainage sinus from the pericardial sac. Four of the five patients were recovered without pericardial constriction. One was discharged with poor condition. In this instance, follow-up study couldn`t be made.

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비위생매립지 침출수의 안정화 평가 - 노은매립지 사례연구 - (The Assessment of Stabilization of Open-dumping Landfill Leachate - A Case Study of Noeun Landfill -)

  • 홍상표
    • 환경영향평가
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    • 제13권3호
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    • pp.115-124
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    • 2004
  • To utilize a closed municipal solid waste landfill site in environmentally secure conditions, it is necessary to verify the stabilization level of landfill leachate. To assess leachate stabilization of an open-dumping municipal solid waste landfill (Noeun Landfill) which is located at the upper drainage basin of Namhan River which flows into Lake Paldang utilized for Seoul Metropolitan water supplies, the surrounding characteristics of the landfill site was surveyed. After then, leachate, groundwater and soil samples from this landfill were chemically analyzed, and the analysis results were evaluated by "The Criteria of Landfill Waste Stabilization(CLWS)", "Discharge Criteria of Landfill Leachate", "The Criteria of Domestic Use in Groundwater Quality", and "Soil Contamination Criteria" promulgated by Korean Ministry of Environment. The closed open-dumping landfill was equipped with the final soil cover, 3 groundwater monitoring wells and poor landfill gas extraction devices for the post-closure management of the landfill. BOD/CODcr ratios in leachate were less than or slightly higher than 1/10. This results seemed to imply that the leachate stabilization level of this landfill based on the CLWS was almost completed. Qualities of groundwater sampled from monitoring wells located at outside of landfill were adequate for "The Criteria of Domestic Use in Groundwater Quality". Finally, concentrations of soil contaminants that were likely to be influenced by this landfill site were adequate to "Soil Contamination Criteria".

포장가속시험 및 경제성 분석을 통한 절삭 덧씌우기와 비절삭 덧씌우기의 비교 (Comparison of Asphalt Concrete Inlay and Overlay for Rehabilitation of Aged Cement Concrete Pavement through Accelerated Pavement Testing and Life-Cycle Cost Analysis)

  • 서영찬;권홍준;이응준
    • 한국도로학회논문집
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    • 제19권6호
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    • pp.75-81
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    • 2017
  • PURPOSES : So far, aged cement concrete pavement on express highways has been rehabilitated mainly with asphalt concrete inlay. However, potholes were the major problem, and they shortened the life of the inlay mainly owing to the poor drainage of water once it infiltrated the interface of the concrete and asphalt. The purpose of this study is to compare the performance and economic efficiency of asphalt overlay and inlay. METHODS : Overlay and inlay were compared through accelerated pavement testing, and a life-cycle cost analysis was conducted in this study using the CA4PRS program. RESULTS and CONCLUSIONS : It was found from accelerated pavement testing that the overlay exhibited reflective crack resistance that was more than twice as effective as that of inlay. The total cost (construction cost + user cost) within the analysis period (20 years) of the overlay was 37% lower than that of the inlay.

슬러지가 혼합된 지반의 공학적 안정 특성에 관한 연구 (A Study on Geotechnical Stability of the Sludge Mixed Soil)

  • 황성필;정재형
    • 한국방재안전학회논문집
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    • 제10권1호
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    • pp.55-60
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    • 2017
  • 슬러지를 매립하는 경우 빗물의 유입이나 주변 지하수의 수분을 흡수하여 지반이 전체적으로 연약해 지는 경우가 발생한다. 본 연구에서는 탈수한 염색슬러지를 매립한 경우의 문제점을 확인하기 위해 염색슬러지와 염색슬러지-토사 혼합샘플에 대한 시험을 수행하였다. 염색슬러지가 배수가 원활하지 못한 매립지 내부에서 함수비가 높은 상태로 장기간 방치되면, 염색공장의 염색슬러지와 비교하여 투수성이 약 3/100 수준으로 낮아지고 압축성이 1.4배 증가하는 것으로 나타났다. 매립지의 안정성 확보를 위해 매립지 내부 함수비를 저하시키는 것이 중요하며, 배수로의 확보와 침출수 배제시설을 통한 관리가 필요할 것으로 판단된다.

신생아 위 자연천공에 대한 임상적 고찰 (Clinical Review of Spontaneous Gastric Perforation in the Newborn)

  • 황승욱;박진영;장수일
    • Advances in pediatric surgery
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    • 제9권1호
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    • pp.30-34
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    • 2003
  • Spontaneous gastric perforation in the newborn is a rare disease that requires early diagnosis and prompt surgical treatment. Between 1988 and 2001 at the Department of Pediatric Surgery. Kyungpool National University Hospital, 9 cases of spontaneous gastric perforation were treated. Seven were males and two females. The mean gestational age and birth weight were 36.7 weeks and 2,455 g respectively. All patients presented with severe abdominal distention and pneumoperitoneum on cross table lateral film of the abdomen. Perforations were located on the anterior wall along the greater curvature of the stomach in six and on the posterior wall along the greater curvature in two. One case showed two sites of perforation on the anterior and posterior wall along the greater curvature. Six patients were managed with debridement and primary closure and the others with debridement and partial gastrectomy. Peritoneal drainage was not performed. There were four deaths; two from sepsis due to leakage from the anastomotic site, one as a result of acute renal failure, and the other by associated respiratory distress syndrome. Spontaneous gastric perforation in the newborn is usually located along the greater curvature. Elevated intragastric pressure is a possible cause of the perforation. Poor prognosis is related to associated diseases and prematurity.

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Impacts of Climate Change on Water Crisis and Formation of Green Algal Blooms in Vietnam

  • Thriveni, Thenepalli;Lee, Namju;Nam, Gnu;Whan, Ahn Ji
    • 에너지공학
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    • 제26권1호
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    • pp.68-75
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    • 2017
  • Global warming affects water supply and water resources throughout the world. In many countries, climate change affects significantly on the fresh water resources. Vietnam is exposed mainly, to landslides and floods triggered by tropical storms and monsoon rains, although storm surge, whirlwind, river bank and coastal line erosion, hail rain. In addition to the prevalent drought, there are many major water challenges, including water availability, stress, scarcity and accessibility, because of poor resource management. Fast growth of urbanization, industrialization and population growth, agricultural activities and climate change cause heavy pressure on water quality. Both domestic and industrial wastewater, as well as storm water shares the same drainage. The common facilities for wastewater treatment are not available. Therefore, wastewater is treated only superficially and then discharged directly into rivers and lakes causing serious pollution of surface water environment. In this paper, we reported the severe water crisis and massive green algal blooms formation in Vietnam rivers and lakes. This is the biggest evidence of climate change variations in Vietnam.

다목적이고 적극적인 빗물관리에 의한 기후변화 적응방안과 국내 사례 (Climate Change Adaptation Strategy by Multipurpose, Proactive Rainwater Management and Case Studies in Korea)

  • 한무영;문정수;김충일
    • 상하수도학회지
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    • 제23권2호
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    • pp.223-230
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    • 2009
  • Most urban water management systems are becoming vulnerable to flooding and drought due to the climate change (CC), urbanization and energy shortage. Despite of poor water management circumstances caused by extremely uneven annual rainfall and hilly terrain, traditionally we have made a sound and sustainable life based on our own philosophy and technologies which copes with our rigid environment. In this study a new paradigm of rainwater management is suggested and multipurpose and creative rainwater harvesting and management (RWHM) systems are introduced providing several case studies such as rainfall storage drainage (RSD) system, rainwater infiltration facilities and star city RWHM system. This new RWHM paradigm leads Seoul Metropolitan Government (SMG) in the Republic of Korea to change regulations and politics for the integrated RWHM. Finally, RWHM is expected to improve the safety, efficiency, energy consumption of urban water infrastructure, to reduce urban heat island phenomenon and, furthermore, to contribute in finding solutions for worldwide water issues and to adapt CC.

Production Practices for North American Ginseng: Challenges and Opportunities

  • Proctor John T.A.
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 2002년도 학술대회지
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    • pp.212-226
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    • 2002
  • North American ginseng production may have been maximized in the traditional growing areas in the last decade and further increases may be in woods grown root, for niche markets. The marketplace demands high quality roots. Most problems leading to low quality roots start with the grower and can be avoided. These include poor site selection, inadequate soil drainage, untimely and poorly applied pesticides, and neglect of good sanitary practices. Selection of low lying sites increased the plant damage from frost in Ontario in May 2002. Seeding is still the major method of propagation of ginseng in spite of some success in culturing different parts of the plant. Opportunities exist for shortening the stratification period of North American ginseng seed to allow spring planting. This may reduce disease incidence. Since only one-third of ginseng seed sown ultimately produces plants harvested after 3 years any approach that reduces disease incidence and improves seed germination, seedling emergence and crop stand must be pursued. Disease is the major problem in ginseng cutivation from seed stratification, soil preparation prior to planting, right through to drying of the roots. Replant disease remains as an unresolved problem and needs full characterization and new approaches for control. Much progress has been made in research and related extension activities in disease control although challenges will arise such as with Quintozene and its replacement with Quadris for control of diseases caused by Rhizoctonia. Decreased labor populations and increased associated costs for ginseng production are causing rapid mechanization in every aspect of the ginseng industry. Engineers, machinery dealers, and fabricators, and growers are being challenged to increase efficiency by mechanization.

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A Study on Features of Forage Barnyard Millet and Related Research Trends

  • Lim, Eun-A;Lee, Ki-Won;Choi, Bo Ram;Park, Hyung Soo;Woo, Jae Hoon;Kim, Da In;Lee, Sang-Hoon
    • 한국초지조사료학회지
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    • 제41권3호
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    • pp.217-222
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    • 2021
  • Barnyard millet is a short-lived tropical, short-term C4 plant and has superior vitality in humid conditions owing to its freshwater habitat. It shows strong adaptability to soils with poor drainage and low fertility, and efficiently competes with rice in paddy fields. Barnyard millet grain is used as feed in the Indian region and is a great source of dietary fiber, proteins, fats, vitamins, and some essential amino acids. Considering its high nutritional value and its potential as a food resource and fodder crop, various countries are showing interest in cultivating barnyard millet. However, in Korea, farm households have not yet recognized the benefits of cultivating barnyard millet, and research regarding this is scarce. In this review, the features of forage barnyard millet and its related research trends are discussed, with the aim of improving interest in this crop and promoting its cultivation.