• 한국지반환경공학회 논문집
• /
• 제12권3호
• /
• pp.47-54
• /
• 2011

절토비탈면에서 발생되는 낙석에 대한 안정성을 확보하기 위해 설치되는 낙석방지 울타리는 기본적으로 12.5m 높이에서 400kg인 암괴가 낙하될 때 발생되는 50kJ의 충격에너지를 가정하여 설계되고 있다. 그러나 암괴의 크기가 커지거나 높이가 높은 곳에서 낙하하는 경우에는 기존의 낙석방지울타리로는 안정성 확보가 어려운 실정이다. 본 논문은 낙석해석프로그램을 이용하여 암괴중량에 따른 비탈면 높이, 울타리와의 이격거리, 경사각 등의 변화를 주어 낙석에 대한 안정성 분석을 실시하여 보았다. 해석결과 기존의 2.5m 높이의 낙석방지울타리는 설계하중 조건인 400kg 암괴가 낙석 될 때, 비탈면 높이가 20m 이내의 일부를 제외하고 대부분 낙석에 대해 안정성이 확보될 수 있으나, 20m 이상인 경우 낙석의 튀는 높이가 낙석방지울타리를 넘는 경우가 빈번하고 낙석의 충격에너지도 설계충격에너지 이상인 경우가 발생되는 결과를 얻을 수 있었다. 그러므로 낙석방지울타리의 설계 시 표준도에 준하여 설계하는 방식보다 지반조건에 따른 낙석의 안정성 검토를 실시한 후에 낙석 도약높이 및 충격에너지를 평가하여 낙석방지울타리를 설계하는 것이 적절할 것으로 판단된다.

• 농약과학회지
• /
• 제20권3호
• /
• pp.228-235
• /
• 2016

작물재배 관행과 지형에 의한 농약의 유실양상의 차이를 파악하고자 고추재배 경사지 포장에서 농약유출 실험을 수행하였다. Azoxystrobin 20% 액상수화제를 2004년과 2005년에 살포한 후 작물체를 씻어 내리는 빗물과 유출수 중 azoxystrobin의 잔류 양상을 추적하였다. 농약살포 후 작물체 표면에 부착되었던 azoxystrobin이 빗물에 씻겨 내리는 정도는 살포량의 24~68% 수준이었다. Azoxystrobin의 첫 번째 유출농도는 $50{\mu}gL^{-1}$ 미만이었고, 10% 경사구의 유출률은 0.26~0.59%, 20% 경사구의 유출률은 0.66~0.96%, 30% 경사구의 유출률은 0.84~1.78%로 경사장의 증가에 따라 줄어들었다. Azoxystrobin의 유출률은 유출수량과 관계가 밀접하고, 단위면적당 유출수량은 두둑과 멀칭효과에 의해 감소하였다.

• KIEE International Transactions on Power Engineering
• /
• 제4A권3호
• /
• pp.146-151
• /
• 2004

The most widely used primary protection for the internal fault detection of the power transformer is current ratio differential relaying (CRDR) with harmonic restraint. However, the second harmonic component could be decreased by magnetizing inrush when there have been changes to the material of the iron core or its design methodology. The higher the capacitance of the high voltage status and underground distribution, the more the differential current includes the second harmonic during the occurrence of an internal fault. Therefore, the conventional second harmonic restraint CRDR must be modified. This paper proposes a numerical algorithm for enhanced power transformer protection. This algorithm enables a clear distinction regarding internal faults as well as magnetizing inrush and steady state. It does this by analyzing the RMS fluctuation of terminal voltage, instantaneous value of the differential current, RMS changes, harmonic component analysis of differential current, and analysis of flux-differential slope characteristics. Based on the results of testing with WatATP99 simulation data, the proposed algorithm demonstrated more rapid and reliable performance.

• 한국농촌건축학회논문집
• /
• 제2권1호
• /
• pp.101-112
• /
• 2000

Green environment is most important factor to human being taking a side view of psychological aspect. But, as the civilization progresses rapidly, the green environment decreases. At present, various environmentally friendly methods are developed to prevent the ill effect of the concretes. n this study, Ecostone retaining wall method, which is a kind of environmentally friendly block, are used for verifying the application to the slope stability and protection of rural hosing. In case of rural hosing and structure, the height of the slope is not high and additional loading doesn't act on the slope except the gravity loading of housing and structure. From the result of the stability analysis of Ecostone, 3m to 7m Ecostone retaining wall can have an equivalence capacity comparing with the concrete retaining wall. Therefore, Ecostone method can apply to retaining wall with the structural safety and environmentally friendly aspect using the plants and vegetation.

• 한국환경과학회지
• /
• 제13권6호
• /
• pp.505-512
• /
• 2004

This study was attempted to review the information data for minimizing the destruction of environmental naturalness and the visual damage of landscape from road construction by establishing a model of environmental naturalness for national roads in the suburb areas to suggest an answer to a research question, ' hat does decide the environmental naturalness of roadscape?'. We found that 1) The road-side slope showed no statistical significance in the description of environmental naturalness of roadscape, but the fact that the road-side slope from road construction is the destruction of natural topography cannot be overlooked. 2) In terms of the direction of value variations for independent variables, signboard and telegraph post, soundproofing and protection wall, structure, and building acted toward negative (-) direction, while mountains, sky, road trees, fields, and surrounding green including the road-side slope acted toward positive(+) direction. 3) The variable with highest relative contribution to dependent variables among independent variables is building, which has importance as many as 148 times of road-side slope, while the variable road-side slope has the least importance. Building has the importance of 7.22 times, mountains 5.51 times, road trees 2.59 times, surrounding green 2.54 times, structure 2.41 times, signboard and telegraph post 2.37 times, soundproofing and protection wall 2.20 times, and sky 1.32 times of the fields as a standard criterion values 1.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2000년도 사면안정 학술발표회
• /
• pp.3-38
• /
• 2000

Slope draperies in soil and rock are a well known method to avoid rockfalls into the roads or onto housings. Common wire mesh or a combination of wire mesh and wire rope nets are pinned to the slope by the means of fully grouted nails or anchors. Most of these installations have not been designed to stabilize the slope, but simply avoid the rocks from bouncing. The combination of soil- or rocknailing with a designable flexible facing system offers the advantage of a longterm stabilization of slopes and can replace other standard methods for slope stabilization. The capability to transfer axial and shear loads from the flexible facing system to the anchor points is most decisive for the design of the stabilization system. But the transfer of forces by mesh as pure surface protection devices is limited on account of their tensile strength and above all also by the possible force transmission to the anchoring points. Strong wire rope nets increase the performance for slope stabilizations with greater distances between nails and anchors and are widely used in Europe. However, they are comparatively expensive in relation to the protected surface. Today, special processes enable the production of diagonally structured mesh from high-tensile steel wire. These mesh provide tensile strengths comparable to wire rope nets. The interaction of mesh and fastening to nail / anchor has been investigated in comprehensive laboratory tests. This also in an effort to find a suitable fastening plates which allows an optimal utilization of the strength of the mesh in tangential (slope-parallel) as well as in vertical direction (perpendicular to the slope). The trials also confirmed that these new mesh, in combination with suitable plates, enable substantial pretensioning of the system. Such pretensioning increases the efficiency of the protection system. This restricts deformations in the surface section of critical slopes which might otherwise cause slides and movements as a result of dilatation. Suitable dimensioning models permit to correctly dimension such systems. The new mesh with the adapted fastening elements have already been installed in first pilot projects in Switzerland and Germany and provide useful information on handling and effects.

• Geomechanics and Engineering
• /
• 제33권1호
• /
• pp.29-40
• /
• 2023

Xanthan gum and starch compound biopolymer (XS), an environmentally friendly soil-binding material produced from natural resources, has been suggested as a slope protection material to enhance soil strength and erosion resistance. Insufficient wet strength and the consequent durability concerns remain, despite XS biopolymer-soil treatment showing high strength and erosion resistance in the dried state, even with a small dosage of soil mass. These concerns need to be solved to improve the field applicability and post-stability of this treatment. This study explored the utilization of an alkaline-based cation crosslinking method using calcium hydroxide and sodium hydroxide to induce non-thermal gelation, resulting in the enhancement of the wet strength and durability of biopolymer-treated soil. Laboratory experiments were conducted to assess the unconfined compressive strength and cyclic wetting-drying durability performance of the treated soil using a selected recipe based on a preliminary gel formation test. The results demonstrated that the uniformity of the gel structure and gelling time varied depending on the ratio of crosslinkers to biopolymer; consequently, the strength of the soil was affected. Subsequently, site soil treated with the recipe, which showed the best performance in indoor assessment, was implemented on the field slope at the bridge abutment via compaction and pressurized spraying methods to assess feasibility in field implementation. Moreover, the variation in surface soil hardness was monitored periodically for one year. Both slopes implemented by the two construction methods showed sufficient stability against detachment and scouring, with a higher soil hardness index than the natural slope for a year.

• 한국지반신소재학회논문집
• /
• 제8권4호
• /
• pp.47-51
• /
• 2009

우리나라의 자연재해는 대부분 풍수해에 의해 발생하며, 강우시 산비탈이 갑작스럽게 붕괴되는 산사태로 인해 큰 재난을 겪고 있다. 사면파괴를 유발하는 요인은 다양하고 요인들이 서로 관련이 있기 때문에 어느 하나의 요인에 의하여 사면파괴의 발생을 설명할 수는 없으나, 외적요인 중 강우는 가장 중요한 외적요인이다. 따라서, 본 논문에서는 무보강된 일반사면과 친환경 호안구조물로 사면보호공법이 적용된 사면을 대상으로 실내 강우재현실험을 수행하였으며, 강우강도와 사면경사에 따른 유출량과 저류량을 분석하여 호안구조물의 침식에 대한 사면보호효과에 대하여 검토하였다.

• 예술인문사회 융합 멀티미디어 논문지
• /
• 제7권6호
• /
• pp.681-692
• /
• 2017

최근 들어 사회 간접시설 확충 및 경제발전 계획에 의하여 전국적으로 도로 확포장공사 및 신도시 건설 등 대규모 공사가 이루어지며 이로 인하여 인위적인 사면 훼손이 급격히 증가되고 있다. 기존의 비탈면녹화공법인 식생 기반재 취부공법은 결합력의 부족이나 건조화, 유기물의 부족 등의 문제점들을 보이고 있다. 본 연구에서는 천연부엽토, 바크퇴비, 코코피트, 질석이 포함되어 사용되고 있는 식생 기반재와 친환경적인 토양첨가제를 활용하여 연구수행을 하였다. 토양첨가제의 혼합비율에 따라 압축강도를 측정하였으며 식생 기반재와 토양첨가제를 혼합하여 흙다짐시험방법을 준용하여 몰드높이, 다짐횟수, 다짐방법(층), 양생 조건 등으로 하여 사면 보호용 녹생토 재료특성에 관한 실험을 진행하였다. 실험결과, 석고계 시멘트를 사용한 토양 첨가제에서 우수한 강도 성능이 나타났으며, 성능 향상제와 pH조절제를 사용함으로써 식생 생육기준에 만족하였다. 녹생토와 토양첨가제의 혼합에 따라 강도가 증가하는 것을 확인 할 수 있었으며, 사면 보호 안정성을 높일 수 있을 것으로 판단된다.

• 한국지반환경공학회 논문집
• /
• 제24권5호
• /
• pp.21-28
• /
• 2023

본 논문에서는 시험적 연구를 통해 초속경 복합매트의 물성을 제시하고, 수치해석적 연구를 통해 지반조건, 강우량, 비탈면 기울기, 성토 높이 등에 따른 초속경 복합매트의 비탈면 보호효과를 분석한 연구를 다루었다. 그 결과 모든 조건에서 초속경 복합매트를 적용할 경우 비탈면 안전율은 증가하였으며, 안전율 증가율은 건기 시와 우기 시 모두 평균 40%의 증가율을 보였다. 이러한 연구결과를 통해 초속경 복합매트의 비탈면 보호효과를 입증하였으며, 초속경 복합매트는 비탈면 유실 및 붕괴가 예상되는 구간에 적용하기 적합할 것으로 사료된다.