• 유기물자원화
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• 제5권1호
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• pp.71-85
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• 1997

현재 우리나라에서 휴 폐광된 광산수는 약 500여개가 넘는 것으로 추정되고 있다. 휴 폐광된 광산은 경관의 저해 및 분진발생, 중금속에 의한 토양, 지하수 및 하천오염, 산성광산 배수의 생선, 지반붕괴 등 안전사고의 위험 등의 환경문제를 안고 있다. 국내에서 조사된 일부 휴 폐광된 금속광산의 오염현황을 보면 폐석 방치, 침출수, 갱내수의 유출, 인근 하천 및 토양의 중금속 오염, 시설물의 붕괴위험을 안고 있는 폐광산이 상당히 발견되고 있다. 휴 폐광된 광산의 관리대책으로서는 법규를 정비하여 토양환경보전법에 광산지역의 토양오염기준 복원기준 등이 설정되어야 한다. 또한 광산폐수, 폐기물을 적절히 처리해야 하며 지반침하대책 및 폐광의 지하공간 활용 등에 관한 연구가 진행되어야한다. 이러한 대책을 추진하기 위해서는 무엇보다도 먼저 휴 폐광에 대한 조사가 선행되어야 하며 오염복원순위의 설정, 재원 및 전문인력의 확충이 필요하다.

• 한국산림과학회지
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• 제15권1호
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• pp.49-60
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• 1972

1972년(年) 8월(月) 18, 19 양일간(兩日間)의 호우(豪雨)(424.1mm)시(時)에 산지(山地)의 단위면적내(單位面積內)에 붕괴발생지(崩壞發生地)가 많았던 안성천유역(安城川流域)의 동북지역(東北地域) 약(約) 20,750 ha의 산지(山地)에서 발생(發生)된 mass soil movement 현상(現象)의 몇 가지 특성(特性)을 조사분석(調査分析)하였다. 결정편암지대(結晶片岩地帶)에서는 계안(溪岸)에 안상(岸狀) 및 여상붕괴(鑢狀崩壞)가, 또 화강암지대(花崗巖地帶)에서는 중상복부(中上腹部)에서 토석유형(土石流型)의 선상(線狀), 판상(板狀) 및 패각상산붕(貝殼狀山崩)이 많이 발생(發生)되었으며, 또 유립목지(有立木地)나 독나지(禿裸地)에서 보다도 치수(稚樹) 유령목지(幼齡木地) 및 척악임지(瘠惡林地)에서 많이 발생(發生)되었다. 평행사면(平行斜面)이나 상승사면(上昇斜面)에서 보다도 하강사면(下降斜面)이나 복합사면(複合斜面)에서, 특(特)히 변곡천이점부위(變曲遷移點部位)에서 많이 발생(發生)되었으며, 산록(山麓)에서 산중복부위(山中腹部位)보다도 중복(中腹)에서 상복(上腹)에 이르는 주곡(主谷)의 최상부(最上部) 분곡부위(分谷部位)에서 가장 많이 발생(發生)되었다. 이 연구결과(硏究結果) 예방치산계획수립(豫防治山計劃樹立)에 필요(必要)한 황폐위험지역(荒廢危險地域)의 판정(判定)에 유용(有用)한 자료(資料)가 될 것이다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.188-188
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• 2016

The Mekong which is one of the world's most significant rivers plays an extremely important role to South East Asia. Lying across six riparian countries including China, Myanmar, Thailand, Laos, Cambodia and Vietnam and being a greatly biological and ecological diversity of fishes, the river supports a huge population who living along Mekong Basin River. Therefore, much attention has been focused on the giant Mekong Basin River, particularly, the soil erosion and sedimentation problems which rise critical impacts on irrigation, agriculture, navigation, fisheries and aquatic ecosystem. In fact, there have been many methods to calculate these problems; however, in the case of Mekong, the available data have significant limitations because of large area (about 795 00 km2) and a failure by management agencies to analyze and publish of developing countries in Mekong Basin River. As a result, the Universal Soil Loss Equation (USLE) model in a GIS (Geographic Information System) framework was applied in this study. The USLE factors contain the rainfall erosivity, soil erodibility, slope length, steepness, crop management and conservation practices which are represented by raster layers in GIS environment. In the final step, these factors were multiplied together to estimate the soil erosion rate in the study area by using spatial analyst tool in the ArcGIS 10.2 software. The spatial distribution of soil loss result will be used to support river basin management to find the subtainable management practices by showing the position and amount of soil erosion and sediment load in the dangerous areas during the selected 56- year period from 1952 to 2007.

• 한국토양비료학회지
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• 제8권3호
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• pp.161-170
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• 1975

Status of agriculture in Jeju province were investigated to find out problems and solutions in view of weather, soils and crop productions. Two hundred harmful windy days per year force to build strong wind-break forest near to farm. Somewhat severe drought situation in croping could be completely avoided by good irrigation system using abundant underground water resources. Poor fertility of soils should be improved by using much compost, lime, fused phosphate, and high dose fertilizers. Optimum fertilizer level for each crop should be determined with special consideration on characteristics of volcanic ash soil.

• 전산구조공학
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• 제2권3호
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• pp.85-95
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• 1989

본 논문에서는 Rayleigh파, 전단파 및 압축파의 영향을 동시에 해석할 수 있는 주파수 종속 무한요소와 이를 이용한 지반-구조물의 동적상호작용의 해석법에 대하여 연구하였다. 방사적으로 전파되는 응력파의 성분에 대한 무한요소와 아울러 매립(Embedded)기초나 적층(Layered)지반을 해석하기 위하여 수평으로 전파되는 파를 해석할 수 있는 무한요소를 개발하였고, 요소행렬 구성하기 위한 적분시 하나의 파성분만 존재하는 경우에 대하여 효율적으로 적용되었던 Newton Cotes 적분과 유사한 방법을 Multi-Waves 문제에 알맞게 확장 적용하였다. 이 방법의 타당성은 반무한, 균질 지만의 위에 놓여있는 원형강판과 지반에 묻혀 있는 원통형 강체기초의 Compliance 함수를 구하여 기존의 문헌에 발표된 값과 비교함으로써 검증하였다. 예제해석은 지진하중을 받는 원자력발전소 격납구조를 대상으로 하여 수행하였으며, 매립깊이의 크기, 지반의 재료감쇠 및 지반의 모형기법에 따른 구조물-지반의 상호작용의 해석결과를 비교 분석하였다.

• 한국농공학회지
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• 제39권5호
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• pp.64-70
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• 1997

Sludge is generated in the process of water and wastewater treatment, and it has been causing various problems environmentally and economically. The firing technology in pottery industry was applied to the sludge treatment, and the final product was called artificial soil. For the production of artificial soil, lime and chabazite was used as additive, and the mixed material was thermally treated in the firing kiln at $300^{\circ}$ temperature for about 15 minutes. The physico-chemical characteristics of the artificial soil was analyzed and it showed that the artificial soil could be used as a soil conditioner for farmland. The concentrations of the toxic heavy metals in the artificial soil were lower than those in the soil quality standard for farmland. It was high in permeability, total nitrogen and total phosphorous concentrations and surface area of the artificial soil compared to the common field soil. Preliminary cost analysis showed that the sludge treatment cost for artificial soil was less than the disposal cost in the current landfill disposal method. This study illustrated that the artificial soil production process can be a feasible alternative for sludge treatment, and produced artificial soil may he applied to farmland without causing significant adverse effect. Further study is recommended for practical application of the system and verification of the longterm effect of the artificial soil on farmland.

• Geomechanics and Engineering
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• 제35권1호
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• pp.95-108
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• 2023

Soft soil ground is a crucial factor limiting the development of the construction of transportation infrastructure in coastal areas. Soft soil is characterized by low strength, low permeability and high compressibility. However, the ordinary treatment method uses Portland cement to solidify the soft soil, which has low early strength and requires a long curing time. Microbially induced carbonate precipitation (MICP) is an emerging method to address geo-environmental problems associated with geotechnical materials. In this study, a method of bio-cementitious mortars consisting of MICP and cement was proposed to stabilize the soft soil. A series of laboratory tests were conducted on MICP-treated and cement-MICP-treated (C-MICP-treated) soft soils to improve mechanical properties. Microscale observations were also undertaken to reveal the underlying mechanism of cement-soil treated by MICP. The results showed that cohesion and internal friction angles of MICP-treated soft soil were greater than those of remolded soft soil. The UCS, elastic modulus and toughness of C-MICP-treated soft soil with high moisture content (50%, 60%, 70%, 80%) were improved compared to traditional cement-soil. A remarkable difference was observed that the MICP process mainly played a role in the early curing stage (i.e., within 14 days) while cement hydration continued during the whole process. Micro-characterization revealed that the calcium carbonate filling the pores enhanced the soft soil.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.966-972
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• 2009

Soil-aggregate system in pavement foundations exist in unsaturated conditions. However, change in water content on foundation layers due to joint and structural cracks during rainfall may cause problems like layer deformations or partial settlements. Therefore, a need exist to evaluate the infiltration and drainage capacity of soil-aggregate foundation system under both saturated and unsaturated conditions. To do that, a laboratory soil-water characteristic curve and permeability under unsaturated conditions are assessed to establish hydraulic properties of geomaterials and limited numerical analysis are performed respectively. As a result, it was found that suction profiles and drainage process was greatly influenced by the initial suction of soil-aggregate system at the time of infiltration, soil water characteristics curves, and hysteresis effects.

• Geomechanics and Engineering
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• 제28권4호
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• pp.405-419
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• 2022

Cavity expansion and contraction solutions for cylindrical and spherical cavities in unsaturated residual soils are presented in this paper. Varying soil state in the plastic zone is accounted by a numerical approach, wherein an element-by-element discretization of the plastic zone of both expanding and contracting cavities is carried out. Unlike existing methods utilizing self-similarity technique, the solution procedure enables the prediction of entire soil-state at any stage of expansion and subsequent contraction. It is also applicable for both cavity creation and expansion problems. The approach adopts constant contribution of suction to effective stress (constant X^s drainage condition) for analysis. The analysis procedure is validated by interpreting the previously reported pressuremeter test results in lateritic residual soil. The typical cavity expansion and contraction characteristics of unsaturated Indian lateritic soil were then examined using this solution procedure. The effect of initial soil-state on cavity limit pressure, plastic radius, reverse yield pressure, and reverse plastic radius are also presented.

• Geomechanics and Engineering
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• 제11권1호
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• pp.59-76
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• 2016

Penetration problems in geomechanics are common. Usually the soil is heavily disturbed around the penetrating bodies and large deformations and distortions can occur. The simulation of the installation of displacement piles is a good example of the interest of these types of problems for geomechanics. In this paper the Material Point Method is used to overcome the difficulties associated with the simulations of problems involving large deformation and full displacement type penetration. Recent modifications of the Material Point Method known as Generalized Interpolation Material Point and the Convected Particle Domain Interpolation are also used and evaluated in some of the examples. Herein a footing submitted to large settlements is presented and simulated, together with the processes associated to a driven pile under undrained conditions. The displacements of the soil surrounding the pile are compared with those obtained by the Small Strain Path Method. In addition, the Modified Cam Clay model is implemented in a code of MPM and used to simulate the process of driving a pile in dry sand. Good and rather encouraging agreement is found between compared data.