• 제목/요약/키워드: drainage method

검색결과 902건 처리시간 0.029초

농촌마을 개발계획 지원을 위한 토지 이용계획 모형( I ) - GIS, CA 및 MCE 법을 이용한 모형의 개발 - (A Land Use Planning Model for Supporting Improvement of Rural Villages ( I ) - Development of Model using GIS, CA and MCE -)

  • 정하우;최진용;김대식
    • 한국농공학회지
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    • 제44권4호
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    • pp.85-98
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    • 2002
  • The purpose of this study is to develop a land use planning model (LUPM) which can be applied to development of rural villages considering their spatial expansion. The LUPM finds out and allocates the new built site required for the improvement of existing villages. in the development of LUPM, CA (cellular automata) and land suitability analysis methods were applied combinedly. The model uses basically numerical data of CIS based on grid data. Agglomerated settlement, as a type of village for simulation, was adopted. Probability of land use change for optimizing development area was calculated by the six criteria: slope. drainage characteristic, direction of slope, as absolute suitability of grid itself, distance from road. distance from stream and distance from the village center, as relative probability by neighborhood cells. Weighting values of these criteria were quantified by AHP (analytic hierarchy process) method, which is one of MCE(multi-criteria evaluation) method. The algorithm of the model was verified by three example villages: an isolation village, a village with horizontal road, and a village with nodal point of cross road

여가전용 주택형 숙박시설의 내부공간계획 연구 (A study on The Space Planning of Housing type Accomodations for Leisure)

  • 김국선;이윤희
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2005년도 추계학술대회 논문집
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    • pp.177-180
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    • 2005
  • In accordance with recent highly advanced economic growth, the demand of leisure life is quite increasing, and also the increase of nature-friendly leisure with health-pursuing concept where human -being enjoys pleasant environment, is to me said as one of recent social traits. Accordingly, it is research the present situation and characteristic of the popularized housing-type accommodating facility, and then this study has discussed on the method how to plan the interior space of such facility to meet with environmental -friendly peculiarity and the object for health enhancement. At first, the program which applied the sustainable design techniques should be preceded, and when planning of interior space, the management method and space planning on the facility and the system should be properly considered in order to enhance the user's health. So to speak, in order to keep and promote the space user's health, those proposing methods such as the followings have been suggested likely as, consideration regarding to air-ventilation and lighting, usage of environmental-friendly material, use of life drainage, custom-typed plane planning, utilization of balcony space, storing furniture and systemization of kitchen space, themed bathroom, inducement of indoor-gardening, and so on. It is expected that this could be applied very usefully to the space plan of the small-scaled housing-type accommodation under planning to develop or renovation.

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순환골재와 쇄석을 이용한 연직배수재의 실내모형실험 (Full-Scale Model Test of Vertical Drain Materials using Recycled Aggregates and Crushed Stone)

  • 이달원;이정준
    • 한국농공학회논문집
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    • 제54권5호
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    • pp.103-111
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    • 2012
  • In this study, the full-scale laboratory model test on utilization of recycled aggregates and crushed stone as vertical drains to use an alternative material of sand in soft ground is performed. The settlement and pore water pressure were measured to evaluate the discharge capacity and filed application, and the results were compared and analyzed through the finite element method. The measured and estimated settlement in all vertical drain materials decreases gradually with the load increase. The measured settlement 6.55~8.63 mm, and the estimated by the Hyperbolic model was 7.45~7.92 mm. So the model used for the analysis can be applied to the settlement estimation of the actual field. The variations of pore water pressure with time showed constantly regardless of the load in all vertical drainage materials. The pore water pressure was similarity to that of sand after rapid drawdown. Therefore, it was applicable to the field because discharge capacity was enough to be an alternative material to the sand which had been being used as the vertical drains.

Experimental study on treatment of waste slurry by vacuum preloading with different conditioning agents

  • Wu, Yajun;Jiang, Haibo;Lu, Yitian;Sun, Dean
    • Geomechanics and Engineering
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    • 제17권6호
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    • pp.543-551
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    • 2019
  • In China, serious environmental problems are induced by the extremely soft construction waste slurries in many urban areas, and there is no appropriate method to treat it presently. In this paper, four model tests were conducted to investigate the efficiency of waste slurry treatment by combining three conditioning agents which can change characteristics of the slurries with a traditional vacuum preloading method. The tests of size analysis of particle aggregate were conducted to investigate the influence of different conditioning agents on the size distributions of particle aggregate. During the model test, the discharged water volumes were monitored. The pore-size distribution and void ratio of the waste slurries after the vacuum preloading were measured by mercury intrusion porosimetry (MIP). It is found that 1) During the natural precipitation, volume of water out of the organic agent is higher than that of the mixed agent, but it is smaller than that of the mixed agent in the vacuum preloading stage; 2) the mixed agent has a higher total volume of water out than the organic agent and the inorganic agent after test, while the organic agent and the inorganic agent have little difference with respect to the drainage effect. The results demonstrate that the combination of mixed conditioning agent and vacuum preloading for the solid-liquid separation in waste slurry has a satisfactory effect and can be applied in engineering practice.

Estimation of stormwater interception ratio for evaluating LID facilities performance in Korea

  • Choi, Jeonghyeon;Lee, Okjeong;Lee, Jeonghoon;Kim, Sangdan
    • Membrane and Water Treatment
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    • 제10권1호
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    • pp.19-28
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    • 2019
  • To minimize the impact of urbanization, accurate performance evaluation of Low Impact Development (LID) facilities is needed. In Korea, the method designed to evaluate large-scale non-point pollution reduction facilities is being applied to LID facilities. However, it has been pointed out that this method is not suitable for evaluating the performance of relatively small-scale installed LID facilities. In this study, a new design formula was proposed based on the ratio of LID facility area and contributing drainage area, for estimating the Stormwater Interception Ratio (SIR) for LID facilities. The SIR was estimated for bio-retentions, infiltration trenches and vegetative swales, which are typical LID facilities, under various conditions through long-term stormwater simulation using the LID module of EPA SWMM. Based on the results of these numerical experiments, the new SIR formula for each LID facility was derived. The sensitivity of the proposed SIR formula to local rainfall properties and design variables is analysed. In addition, the SIR formula was compared with the existing design formula, the Rainfall Interception Ratio (RIR).

On the optimum design of reinforcement systems for old masonry railway tunnels

  • Ghyasvand, Soheil;Fahimifar, Ahamd;Nejad, Fereidoon Moghadas
    • Geomechanics and Engineering
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    • 제28권2호
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    • pp.145-155
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    • 2022
  • Safety is a most important parameters in underground railway transportation; Also stability of underground tunnel is very important in tunneling engineering. Design of a reliable support system requires an evaluation of both ground demand and support capacity. Iran's traditional railway tunnels are mainly supported with masonry structures or unsupported in high quality rock masses. A decrease in rock mass quality due to changes in groundwater regime creep and fatigue in rock and similar phenomena causes tunnel safety to decrease during time. The case study is an old tunnel in Iran, called "Keshvar"; it is more than 50 years old railway organization. In operating this Tunnel, until the several problems came up based on stability and leaking water. The goal of study is evaluation of the various reinforcement systems for supporting of the tunnel. The optimal selection of the reinforcement system is examined using TOPSIS Fuzzy method in light of the looming and available uncertainties. Several factors such as; the tunnel span, maintenance, drainage, sealing, ventilation, cost and safety were based to choose the method and system of designing. Therefore, by identifying these parameters, an optimal reinforcement system was selected and introduced. Based on optimization system for analysis, it is revealed that the systematic rock bolts and shotcrete protection had a most appropriate result for these kind of tunnel in Iran.

Parallel Venovenous and Venoarterial Extracorporeal Membrane Oxygenation for Respiratory Failure and Cardiac Dysfunction in a Patient with Coronavirus Disease 2019: A Case Report

  • Eun Seok Ka;June Lee;Seha Ahn;Yong Han Kim
    • Journal of Chest Surgery
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    • 제57권2호
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    • pp.225-229
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    • 2024
  • Venovenous (VV) extracorporeal membrane oxygenation (ECMO) is a lifesaving technique for patients experiencing respiratory failure. When VV ECMO fails to provide adequate support despite optimal settings, alternative strategies may be employed. One option is to add another venous cannula to increase venous drainage, while another is to insert an additional arterial return cannula to assist cardiac function. Alternatively, a separate ECMO circuit can be implemented to function in parallel with the existing circuit. We present a case in which the parallel ECMO method was used in a 63-year-old man with respiratory failure due to coronavirus disease 2019, combined with cardiac dysfunction. We installed an additional venoarterial ECMO circuit alongside the existing VV ECMO circuit and successfully weaned the patient from both types of ECMO. In this report, we share our experience and discuss this method.

압축지수의 불확실성이 압밀침하 거동에 미치는 영향에 대한 수치적 평가 (A Numerical Study on the Effects on Consolidation Settlement Behavior due to Uncertainty of Compression Index)

  • 변요셉;김광윤;이창기;천병식
    • 한국지반환경공학회 논문집
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    • 제13권11호
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    • pp.43-50
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    • 2012
  • 본 연구에서는 국내외 적용 중인 압밀지수의 값을 조사하고 조사된 표준편차 범위를 분석하였으며, 편차에 따른 침하량을 계산하였다. 또한 지반에서 내재한 불확실성 변수인 압축지수가 연약지반 처리공법 하에서 미치는 영향을 분석하였다. 수치해석을 통해 프리로딩 공법, 배수촉진 공법, 치환 공법을 적용하여 성토단계별 침하거동을 분석하였고, 추가적으로 장기적인 침하에 안정적인 Piled Raft 공법을 추가로 분석하여 침하거동을 파악하였다. 그 결과, 최종침하량에 따른 평균분석 결과는 해석 값의 평균, 해석값의 최대 최소의 중간값, 평균 압축지수(Cc=0.35)를 사용할 경우에 발생된 침하량이 상이한 것으로 나타났다. 최종침하량에 따른 변동계수의 비교 분석 결과, 각 공법별로 시간에 따라 변동계수의 차이를 보였다. 그 중 Piled Raft 공법이 시간의 경과와 상관없이 일정한 변동계수 값을 보이며, 다른 공법보다 낮은 값으로 불확실성 지반정수의 압축지수에 영향이 가장 적은 것으로 확인되었다.

교대말뚝기초의 측방유동에 관한 원심모형실험 (Centrifuge Model Experiments for Lateral Soil Movements of Piled Bridge Abutments.)

  • 최동혁;정길수;박병수;유남재
    • 산업기술연구
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    • 제25권B호
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    • pp.63-71
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    • 2005
  • This paper is an experimental result of investigating lateral soil movements at piled bridge abutments by using the centrifuge model facility. Three different centrifuge model experiments, changing the methods of ground improvement at bridge abutment on the soft clayey soil (no improvement, preconsolidation and plastic board drains (PBD), sand compaction pile (SCP) + PBD), were carried out to figure out which method is the most appropriate for resisting against the lateral soil movements. In the centrifuge modelling, construction process in field was reconstructed as close as possible. Displacements of abutment model, ground movement, vertical earth pressure, cone resistance after soil improvement and distribution of water content were monitored during and after centrifuge model tests. As results of centrifuge model experiments, preconsolidation method with PBD was found to be the most effective against the lateral soil movement by analyzing results about displacements of abutment model, ground movement and cone resistance. Increase of shear strength by preconsolidation method resulted in increasing the resistance against lateral soil movement effectively although SCP could mobilize the resistance against lateral soil movement. It was also found that installment with PBD beneath the backfill of bridge abutment induced effective drainage of excess pore water pressure during the consolidation by embanking at the back of the abutment and resulted in increasing the shear strength of clay soil foundation and eventually increasing the resistance of lateral soil movement against piles of bridge abutment.

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합리식의 유출계수(C) 산정방법의 개선에 관한 연구 (Study on Improved Method for Calculating Runoff Coefficient of Rational Method)

  • 이영대;김종순;김영택
    • 한국방재학회 논문집
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    • 제7권4호
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    • pp.67-74
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    • 2007
  • 합리식은 구조가 간단하고 사용하기 편리하기 때문에 소배수유역의 우수관거 설계에 가장 많이 사용되고 있다. 합리식을 이용한 유출해석에서 가장 중요한 요소인 유출계수 값은 강우강도, 재현기간, 강우의 지속시간, 지표특성 등에 따라 달라지지만 토지이용도에 따라 제시된 일정한 값을 그대로 사용하고 있다. 그러므로 실무자들이 합리식을 이용하여 우수관거 설계를 위한 적정 설계홍수량 산정을 위해서는 유출계수에 영향을 미치는 중요한 인자들을 고려한 통합유출계수의 산정이 필수적이다. 따라서 본 연구에서는 합리식에 대한 기본이론을 검토하고 유출계수에 영향을 미치는 주요인자와 유출과의 관계를 연구하여 합리식에서의 유출계수(C)와 강우지속시간, 재현기간(T) 및 NRCS(Natural Resources Conservation Service)방법에서 CN(유출곡선지수)와의 관계를 연구하여 보다 합리적으로 유출계수를 산정할 수 있도록 하였다.