• Title/Summary/Keyword: Reclaimed ground

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Studies on Salinity and Growth of Rice at Seosan Reclaimed Land (서산 간척지의 염도와 벼의 생육에 관한 연구)

  • 이희선;김옥봉
    • The Korean Journal of Ecology
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    • v.20 no.5
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    • pp.367-373
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    • 1997
  • The effects of salinity on the growth and production of rice were studied at Seosan reclaimed land from July to October, 1995. The plant height, the number of living aleaves, dead leaves and total leaves, the number of the grains and the dry weight of the grains per individual, and the dry weight of above the ground in $25cm{\times}25cm$ quadrat were investigated on 5 plots whers were different salinity. The plant height, the number of living leaves and total leaves and the number of grains and the dry weight of grains per individual, and the dry weight of above the ground decreased as the salinity of water increase and the number of dead leaves of rice increased as the salinity of water decrease. The effect of salinity on the reproductive production is severer than the vegetative production. Because of the salinity, the growth and the production of the rice at Seosan reclaimed land are worse than the normal rice field.

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Effect of Liquefaction Resistence of Fine-Grained Soils on the Reclaimed Land (준설매립지반의 세립토가 액상화 강도에 미치는 영향)

  • Kim, Jong-Kook;Yoon, Won-Sub;Park, Sang-Jun;Chae, Young-Su
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1717-1726
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    • 2008
  • Vibration triaxial compression test was put in influence for liquefaction strength of fine grained soil of dredged and reclaimed ground and consideration for fine fraction content, relative density, overconsolidation ratio and plasticity index in this study. By the results of these test, the liquefaction strength increased with fine fraction content and the relative density, overconsolidation ratio incresed with liquefaction strength too. However, in the case of nonplastic silt was the smalist liquefaction strength which influenced by dilatancy and interlocking when silt content was 34.7%(average grading 0.12mm). Therefore, liquefaction strength of fine grained soil of dredged and reclaimed ground increased with fine fraction content so it will help to make lower liquefaction.

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An Evaluation of the Settlement and Stability in the Reclaimed Revetment by Field Monitoring Method (현장계측을 이용한 호안의 침하 및 안정성의 평가)

  • Kim, Hyeong-Ju;Yang, Tae-Seon;Choe, Deok-Chan
    • Proceedings of the Korean Geotechical Society Conference
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    • 1992.10a
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    • pp.149-155
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    • 1992
  • In case of construction of the final refuse disposal site on the ground where 20m soft clay layer is deposited, Sand Compaction Pile(SCP) was driven with a view to increase the strength and reduce the settlement when the reclaimed revetment intend to be constructed first in a short time. Field monitoring method is carried out in order to overcome the problems of settlement and stability in the construction of the reclaimed revetment and the assumed problems in the design of composite ground. In this paper the observed data from monitoring sections are analysed, fedback to the desigh and field, and compared with FEM analysis. Conclusions are as follow: in case of 70% replacement the use of modified soilparameters makes the FEM analysis of SCP possible. In case of 27% replacement, n(stress concentration ratio)=0.2-0.3, B(measured settleme reduction coefficient)=0.43 are evalated. Also, horizontal displacement is remarkably happened around the ground.

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The Physico-chemical Properties of the Soil at the Grounds of Replanted Zelkova serrata (Thunberg) Markino in Reclaimed Land from the Sea, Gwangyang Bay (광양만 바다 준설 매립지 느티나무의 식재 지반별 토양 이화학적 특성)

  • 김도균;박종민
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.6
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    • pp.85-94
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    • 2004
  • This study was carried out to analyze physicochemical properties according to the soil height and to the six types of sites that were used as planting ground in the reclaimed land from the sea, Gwangyang Bay. The physicochemical properties of the soil types were tested by t-test(p<0.01, 0.05), at each of the 6 planting ground sites(p<0.01, 0.05), and at each height(p<0.01) of the planting grounds. These areas were tested by ANOVA and were significantly different. Improved soil was better than reclaimed soil from the sea for Zelkova growth because the improved soil contained lower amounts of pH, ECe, N $a^{+}$, $Ca^{++}$, $Mg^{++}$ SAR. Due to freedom from variables such as salt content in the underground as well as the physical and chemical disturbance of the soil, favorable planting ground for tree growth was recorded at the higher grounds than at the lower ones. Soil detriment to the tree growth in the studied sites included elements such as soil hardness, and the distribution of sodium in the tree root systems. The planting grounds for the favorable growth of landscape trees were determined in the following order: the grounds of mounding> the coved ground of improved soil, and the filled ground of improved soil.l.l.l.

Roots Growth Characteristics of Zelkova serrata Makino. after Replanting in the Reclaimed Land from the Sea - On the Root Structure and Spatial Distribution of Fine Root Phytomass - (임해매립지의 느티나무 식재 이후 뿌리 생장특성 -뿌리구조 및 세근의 공간적 분포를 중심으로-)

  • Kim, Do-Gyun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.35 no.5
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    • pp.46-55
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    • 2007
  • This study was carried out to analyze both the root structure and the fine root phytomass of the vertical and horizontal distribution of Zelkova serrata Makino. which was transplanted in the reclaimed land from the sea in Gwangyang, Jeonnam, South Korea. The base ground was reclaimed land from the sea. $Z_1$ of the planting ground was filled to a $100{\sim}150cm$ thickness with the improved soil instead of the reclaimed soil from the sea, $Z_2$ of the planting ground was covered to a $20{\sim}30cm$ thickness with the improved soil and $Z_3$ of the planting ground was mounded to 120cm thickness with the improved soil on the reclaimed land from the sea. In addition, $Z_4,\;Z_5\;and\;Z_6$ of the planting grounds were at the large-sized mound on the reclaimed land from the sea. $Z_4$ of the planting ground was located at the lowest level, $Z_5$ planting ground was located at the slope and $Z_6$ planting ground was located at the top of the large-sized mound. The large-sized mounds contain 3 layers, the base layer was reclaimed land from the sea and the second layer was mounded to a $200{\sim}300cm$ thickness with the desalinized soil from the sea on the base layers and the finally layers were mounded to a $80{\sim}120cm$ thickness with improved soil on the second layer. The planting grounds $Z_3,\;Z_4,\;Z_5\;and\;Z_6$ developed roots such as tap roots, lateral roots and heart roots. However, in $Z_1\;and\;Z_2$ roots development were inhibited. The fine-root phytomass of the 6 planting ground types was as follows: $113.5g\;DM/m^2$ for $Z_5$, $105.5g\;DM/m^2$ for $Z_4$, $88.3g\;DM/m^2$ for $Z_3$, $81.0g\;DM/m^2$ for $Z_6$, $73.0g\;DM/m^2$ for $Z_2$, $43.3g\;DM/m^2$ for $Z_1$. The vertical distribution of the fine root phytomass decreased from the upper to the deeper soil profiles in the 6 mound types. The fine root phytomass was $43.3{\sim}71.8%$ in a $0{\sim}20cm$ thickness of soil layer and it decreased according to the distance from the nearest trees. The root growth in the improved soil was better than in the reclaimed soil from the sea. However, root growth decreased more in the disturbed soils even though the planting grounds contained the improved soils. The retarded development of roots and the spatial distribution patterns of the fine root phytomass were closely connected to the reclaimed soil from the sea. In the disturbed soil, the soil hardness and alkalic cation($Na^+,\;K^+,\;Ca^{2+},\;Mg^{2+}$). were high and the soil water was lacking. We suggest that the construction of planting grounds and the improvement of bad soil are necessary for the proper and effective growth of landscaping plants.

Prediction of Consolidational Settlement of Dredged and Reclaimed Ground (준설매립토지반의 압밀침하량 예측)

  • Yoo, Nam-Jae;Park, Byung-Soo;Jeong, Gil-Soo
    • Journal of Industrial Technology
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    • v.21 no.A
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    • pp.317-327
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    • 2001
  • For soils with high void ratios, the inverse method of utilizing results obtained from centrifuge model test was used to find the constitutive relation of effective stress - void ratio - permeability whereas conventional oedometer test and constant rate of strain consolidation test were also used to fine its relation at ranges of relatively low void ratio. Results of column test about settlement of interface and pore pressure and distribution with time were compared with numerically estimated values to confirm such a constitutive relation as obtained from the inverse method. Consolidational settlement in dredged and reclaimed ground, where the consolidation was in progress, was predicted by using the numerical technique implemented with the finite strain consolidation theory.

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Extraction of Environmental Informations for Reclaimed Area using Satellite Image Data (인공위성데이타를 이용한 간척지역의 환경정보의 추출)

  • 안철호;김용일;이창노
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.7 no.1
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    • pp.49-57
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    • 1989
  • On this study, we performed the landuse classification using the Landsat data acquired before and after reclamation, and extracted the ground temperature from infrared band(TM band6) data. Using the satellite data, it was possible to extract changes of landuses effectively according to the reclamation, and could obtain the thermal characteristics of the reclaimed area and the surroundings by converting infrared data value into temperatures of surfaces of ground and water. The result of this analysis will be used for the land management of large-scale reclaimed area applying the satellite data and related information.

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Application of the $\phi=0$ Analysis for Dredged and Reclaimed Ground (준설매립지반에 대한 $\phi=0$ 해석의 적용성)

  • Kim, Ju-Hyun;Jeong, Sang-Kug;Shim, Min-Bo;Lee, Song
    • Journal of the Korean Geotechnical Society
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    • v.20 no.1
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    • pp.21-27
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    • 2004
  • In this test, there was two-dimensional model loading test implemented for analysis with respect to the problem of evaluating bearing capacity and the application range on the dredged and reclaimed ground, so it was possible to get the following result by comparing a result of loading test and an equation proposed previously. When the difference between average undrained shea. strength by (equation omitted)B of loading board width and the strength under. (equation omitted)B is mere than $\pm50%$, the applicability of Nc(coefficient of bearing capacity where $\phi=0$ analysis is considered in the single layer) was declined. As well, using Nc=5.7, 5.14(coeffcient of bearing capacity where $\phi=0$ analysis is applicable to saturated clay without special limit) for evaluating bearing capacity on the dredged and reclaimed ground causes poor applicability, therefore that seem to be applicable when water content is less than about 75% which makes the unconfined compression test possible.

Study on Constructibility considering Changes of Groundwater Level in Kwang Yang port (광양지역 지하수위 변화를 고려한 시공성에 관한 연구)

  • Kim, Byeong-Ho;Yang, Tae-Seon;Lee, Song
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1120-1125
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    • 2006
  • Larger area will be constructed in a harbor land and container terminal which are constructed in reclaimed land using the dredged materials. Soil improvement work is to be carried out including constructibility, in which is monitoring devices, measuring frequency, installations etc. The ground water tables in the reclaimed area are affected by the several factors which are design reclamation level, consolidation settlement, remaining surcharge pressure and remaining excess pore water pressure. The plan wii be drawn up in which monitoring results for the ground water tables are capable to provide the reliable ground water table when designers and civil engineers construct the harbor structures considering constructibility.

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Evaluation of Liquefaction Remediation of Reclaimed Land by Sand Compaction Pile (모래다짐말뚝(SCP)에 의한 매립지반의 액상화저감효과 평가)

  • Kim, Jong-Kook;Son, Hyung-Ho;Yoon, Won-Sub;Chae, Young-Soo;Choi, In-Gul
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1678-1688
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    • 2008
  • In this study, dredging reclamation ground were performed to evaluate the ground improvement and liquefaction reduction effect with the result that standard penetration test(SPT) and piezo penetration test(CPT) before and after of improvement. Especially, the estimate center of the pile and factor of liquefaction safety to the position of ground around with the pile presented improvement of compaction for improved compaction of dredging reclamation ground.

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