• 제목/요약/키워드: soil improvement

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등간격의 매트로 보강된 모래지반의 보강층수에 따른 지지력에 관한 연구 (A Study on Bearing Capacity according to the Number of Reinforcement Layers in Sandy Ground Reinforced by Mats of Equal-intervals)

  • 임종철;박성재;주인곤;이재열;이민희
    • 한국지반공학회논문집
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    • 제15권6호
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    • pp.201-217
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    • 1999
  • 성토지반의 지지력을 향상시키기 위하여 지반개량이나 다짐과 같은 일반적인 방법들이 많이 이용되고 있다. 하치만, 최근에는 내구성이 크고 강한 합성수지와 같은 재료들이 개발되어 실용화됨으로서, 보강토 공법이 널리 적용되고 있는 실정이다. 본 연구에서는, 매트로 보강된 모래지반상의 대상기초에 대한 모형실험을 평면변형률 상태에서 실시하여, 지지력의 증대효과와 지반의 거동을 관찰하였다. 그리고 지지력의 산정식을 개발하여 실험결과와 비교 검토 하였다.

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Hi-FA(유동성 및 점성 개질제)를 이용한 지반보강 및 기존 교량기초 보강공법에 대한 실용화 연구 (Field Application Study for Soil Improvement and Existing Foundation Protection Work by Hi-FA(High performance and Multi functional Agent))

  • 김명학;박명득;윤태국;이용준;박민철
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회
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    • pp.664-675
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    • 2010
  • Recently environment-friendly construction method is major trend in both domestic and world constrction fields. In this paper High Functional Performance Agent(Hi-FA) which has various improved engineering characteristics different with conventional Portland cement grouting, such as high viscosity, liquidity, void filling ability, early hardening, and separation resistance, was analyzed by field and laboratory test. Also soil improvement and existing deep foundation protection works were performed and analyzed using Hi-FA.

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친환경농업 농지 임대차 제도의 개선방향 (The Direction of Improvement of Organic Agricultural Farmland Lease Institution)

  • 최덕천
    • 한국유기농업학회지
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    • 제17권4호
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    • pp.441-461
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    • 2009
  • Switching to organic farming practices in agricultural production reaches the end of the period it takes an average of five years. During this period, agricultural soil management to improve the investment must be sustained. Results of the survey of environment-friendly agricultural lease rates appear to approximately 54.2% lower than agricultural practices. Environmentally friendly agricultural land is leased on a long transition period of the contract cost, many buried incompleteness, uncertainty of contract fulfillment(opportunistic behavior) occurs when the transaction costs. This ultimately can hinder the spread of organic farming. Thus, the qualitative development of organic farming and land leasing in order to minimize transaction costs, should that occur. The alternative 'cooperative long-term lease contract' is a system.

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C.G.S에 의한 기초지반보강효과에 관한 연구 (A Study on the Ground Improvement by Compaction Grouting System)

  • 천병식;여유현;최현석;오일석
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1999년도 춘계학술대회 논문집
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    • pp.375-382
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    • 1999
  • The use of compaction grouting system(C.G.S) evolved in the 1950's to correct structural settlement of buildings. Over the almost 50 years, the technology has developed and is currently used in wide range of applications. Compaction Grouting, the injection of a very stiff 'zero-slump' mortar grout under relatively high pressure, displaces and compacts soils. It can effectively repair natural or man-made soil strength deficiencies in variety of soil formations. Major uses of Compaction Grouting include densifying loose soils or fill voids caused by sinkholes, poorly compacted fills, broken utilities, improper dewatering, or soft ground tunneling excavation. Other application include preventing liquefaction, re-leveling settled structures, and using compaction grout bulbs as structural elements of minipiles or underpinning. So, on the basis of the case history constructed in recent year, a study has been performed to analyze the basic mechanism of the Compaction Grouting and verify the effectiveness of the ground improvement.

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USE OF FIBREDRAIN IN DREDGED CLAY RECLAMATION PROJECT

  • Lee, S.L.;Yong, K.Y.;Soehoed A R
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2001년도 지반환경 및 준설매립에관한 학술세미나
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    • pp.96-109
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    • 2001
  • Land was reclaimed at the waterfront in the Pluit area of Jakarta for a 90ha residential-cum-recreational development. The reclamation works involve construction of permanent and temporary dykes, fill placement, soil improvement, dredging of internal canals and marina, and construction of canal revetment. The site lies on 16m to 18m thick soft seabed deposits. Settlement of the reclaimed areas will result as a consequence of consolidation of the soft underlying sediments. In order to reduce post-construction settlement to within acceptable levels, a system of vertical drains and preloading was adopted. This paper describes the use of Fibredrain, a prefabricated vertical drain made of jute and coir fibres developed at the National University of Singapore, in the soil improvement works and a secondary use in the construction of perimeter dykes for the reclamation works. The construction of the perimeter dyke must be carried out in such a way that slope stability is on ensured. Bamboo rafts and bamboo clusters with Fibredrain inserted, and stage construction were employed to improve stability during the dyke formation for the Pantai Mutiara project.

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경북지역을 중심으로 한우농가의 축분 특성 조사 (Characteristics of Livestock Manure in Hanwoo Farms Centered in Gyeongsangbuk-do Province)

  • 최성업
    • 한국환경과학회지
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    • 제31권3호
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    • pp.281-284
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    • 2022
  • This study focused on the characteristics of manure in five beef cattle farms and two breeding farms in Hanwoo centered in Gyeongsangbuk-do province. The results of analysis and evaluation are as follows; First, the pH of manure in all the farms in this study was within the appropriate range of 8.81 to 9.45. Second, the dry matter content varied from 44.7% to 70.5% for all the farms. Third, the total nitrogen content in all the farms was 2.05-3.04%, which is higher than the reported range; however, it could play a role as a soil improvement agent when used as compost. Fourth, although the exact range of ammonia-N (VBN) content was not reported, results analyzed in all the farms showed that the level of impact on the environment was insignificant. In conclusion, soil and environment improvement effects are expected to be effective if the manure at Hanwoo farms in the Gyeongbuk area are used as compost through appropriate management.

새만금 방조제 내측사면의 식생환경 조사 (A Study for the Environment of Vegetation to the Inside Slope of Sea Dike)

  • 유전용;강병윤;김현태;최경영;양영철;권태영
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2003년도 학술발표논문집
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    • pp.315-318
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    • 2003
  • A study was performed to examine the soil environment, vegetation type to the inside slope of sea dike. The soil pH was about 8.5, electric conductivity was $4.59dSm^{-1}$, soil strength was 12.1mm, organic matter was 0.21%. The vascular plants of the inside slope of sea dike were consisted of 101 taxa such as 26 families, 80 genera, 93 species, 8 varieties, 1 hybrid. The life cycle of the plants was annual 38.6%, biennial 14.8%, perennial 46.5%. As it compared with consistency ratio in the flora of korea, the distribution of annual, biennial appeared highly. From this examine, it appears that the environment need soil improvement using water holding materials and organic supplements.

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사면파괴 지역의 연약점토에 대한 비배수 전단강도 적용에 관한 연구 (A Study of Application of the Undrained Shear Strength of the Soft Clay in the Area of Slope Failure)

  • 정진호;이성록;임창규
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2006년도 춘계 학술발표회 논문집
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    • pp.681-686
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    • 2006
  • This study is to examine slope activity safety ratio on the strength of the natural sample or soil collected through field test in the slope activity region during destruction happened in the course of soil-relocating work planned for ground improvement under strict supervision at the house-building site, using Bishop's slope analysis method and investigate relationship between slope analysis theories and actual destruction so as to compare determining method of clean water of soil essential for slope activity analysis and accuracy of resulting value of clean water of soil.

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Sampling Study on Environmental Observations: Precipitation, Soil Moisture and Land Cover Information

  • 유철상
    • 한국환경과학회지
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    • 제5권2호
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    • pp.103-112
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    • 1996
  • Observational date is integral in our understanding of present climate, its natural variability and any cnange roue to anturopogenic effects. This study incorporates a brief overview of sampling requirements using data from the first ISLSCP Field Experiment (FIFE) in 1987, which was a multi-disciplinary field experiment over a 15km grid in Konza Prairie, USA. Sampling strategies were designed for precipitation and soil moisture measurements and also detecting land cover type. It was concludes that up to 8 raingages would be needed for valuable precipitation measurements covering the whole FIFE catchment, but only one soil moisture station. Results show that as new gages or station are added to the catchment then the sampling error is reduced, but the Improvement in error performance is less as the number of gages or stations increases. Sampling from remoteiy sensed instruments shows different results. It can be seen that the sampling error at 1arger resolution sizes are small due to competing error contribution from both commission and omission error.

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Vacuum distribution with depth in vertical drains and soil during preloading

  • Khan, Abdul Qudoos;Mesri, G.
    • Geomechanics and Engineering
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    • 제6권4호
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    • pp.377-389
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    • 2014
  • The vacuum consolidation method which was proposed by Kjellman in 1952 has been studied extensively and used successfully since early 1980 throughout the world, especially in East and Southeast Asia. Despite the increased successful use, different opinions still exist, especially in connection to distribution of vacuum with depth and time in vertical drains and in soil during preloading of soft ground. Porewater pressure measurements from actual cases of field vacuum and vacuum-fill preloading as well as laboratory studies have been examined. It is concluded that (a) a vacuum magnitude equal to that in the drainage blanket remains constant with depth and time within the vertical drains, (b) as expected, vacuum does not develop at the same rate within the soil at different depths; however, under ideal conditions vacuum is expected to become constant with depth in soil after the end of primary consolidation, and (c) there exists a possibility of internal leakage in vacuum intensity at some sublayers of a soft clay and silt deposit. A case history of vacuum loading with sufficient subsurface information is analyzed using the ILLICON procedure.