• 한국환경복원기술학회지
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• 제14권3호
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• pp.169-176
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• 2011

The purpose of this study is to examine the ecologically suitable restoration characteristics in riparian slopes constructed by continuous fiber soil reinforced system (Geofiber system) which does not contain the concrete materials. The findings are as follows : (1) as the tested soil was not washed away by rainfalls and floods, Geofiber could replace the concrete wall and gravity stone net bag technique from the civil engineering structural point of view; (2) after one year of the construction, it was monitored that land cover ratio was 80-90%, which indirectly shows that vegetation is safely maintained; and (3) at the same time, 5-8 flora species were found in each test grid and more importantly dominant species have been moved from alien species to native herbaceous plants. From the above findings, Geofiber system is recommendable to restore the riparian slopes in terms of stability and natural landscape points. However, a long term monitering is needed considering flora succession process in a given environment as well as suitability tests should be carried out through the comparative investigations in other environments.

• 한국환경복원기술학회지
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• 제1권1호
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• pp.18-27
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• 1998

To investigate the restoration progression on soil physical properties and vegetation at the surface of logging road affected by timber harvesting operation. This study was carried out at logging roads constructed from 1989 to 1994 in Mt. Baekwoon, Kwangyang, Chollanam-do. Judging from the analysis of soil hardness, there were significant changes in the depth of soil between 5 and 10cm. Soil hardness was recovered from the compacted condition to the natural forest condition after 9 years passed. Soil macroporous ratio (pF2.7) of topsoil was higher than that of deep soil. Soil moisture retention of topsoil was more improved than that of deep soil. From the view of soil bulk density, the necessary time for recovering to the undisturbed condition of forest soil was about 10 years in the logging road left. Soil physical properties such as soil bulk density and porous ratio were recovered as time passed. Improved soil physical properties promoted the plant recovery on the logging road surface. The dominant species on the logging roads were Comus kousa, Prunus sargentii as overstory species, Rubus crataegifolius, Lespedeza bicolor as understory species, and Saussurea gracilis, Pteridium aquilinum var. latiusculum as herbaceous species. The plant recovery of bank-slopes was faster than that of cut-slopes and road surface. In progress of year, average plant coverage were 70 to 90% in cut- and bank-slopes and 30 to 60% on the logging road, surface which was elapsed 9 years after logging road construction. Therefore, additional planting and seeding work could be effective to the soil condition and vegetation restoration.

• 한국환경복원기술학회지
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• 제7권4호
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• pp.98-109
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• 2004

This study was conducted to develop revegetation methods for the restoration of the steep slopes by recycling of bark compost and mushroom media. In general, bark compost and mushroom media can be used as soil media for the restoration works, because they can increase infiltration of rainfall and give enough porous to breathe and elongate for the root growth as well as environmental value. This experiment was carried out to know the effect of soil media composed by different ratio of mushroom media for the restoration of steep rock-exposed slopes, and to certificate how soil media(PEC) will be effective to germinate and grow for native plants. The main results of the study are summarized as follows; 1. In percent coverage, the soil media PEC1 is more valuable than PEC2. The seed mixtures recommended by Government of Transportation and Construction can be used at PEC1 and PEC2, but it will be more useful if the total amount of seed are reduced and seed mixtures are altered in a direction of native plants. 2. The soil media is under 20 mm tested by Yamanaka Hardiness Tester which is available for the seed germination and growth. 3. The surface cracks are not occurred in PEC1 and PEC2, but more than 30 cracks per 1 square meter are occurred at soil media which is constructed by normal soil-seed-fertilizer hydro-seeding methods. 4. The soil moisture contents are over 20 percent level during 15 day. Such moisture content in soil media will be effective for the plant growth. By using Terra-Control, PEC can maintain enough soil moisture. 5. The eroded soils from $60^{\circ}$ slopes by artificial rainfall with the intensity of 20 mm/hr in one day after seeding are estimated under 1%. By the results of erosion test, it comes to the conclusion that soil media of PEC can be adapted at steep rock exposed slopes.

• 한국조경학회지
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• 제19권2호
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• pp.75-91
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• 1991

This study is one of studies on the analysis of vegetation spatial image and visual preference of roadside slopes in Chi-Ri Mt. national park. In this article, we analized the soil characteristics and the actual vegetation within slopes and forest lands contiguous to those. The results obtained were summarized as follows; The physical and chemical properties of soil in forest lands were better than slopes and Cheoneun temple - Seongsam pass was the best fertilized among 3 sector. In the structure of woody plants in forest lands, the high importance value species were Pinus denciflora, Quercus aliena within Ukmojeong-Deokdong sector, Q. aliena, Q. varabilis, Q. serrata within Banseon-Seongsam pass sector, and P. denciflora, Q. dentata within Cheoneun temple-Seongsam pass sector. And also, Aster scaber, Arundinella hirta, Pteridium aquilinum were the high importance value herbs within all sector. In slopes, the species diversity indices of woody plants were low, but that of herbs showed slightly high. By the cluster analysis used in similarity index, it was observed that woody plants structure between slopes and forest lands made little, but the herbs made slightly higher than woody plants.

• 한국지반공학회논문집
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• 제25권10호
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• pp.55-65
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• 2009

강우침투에 의한 사면의 표층파괴는 국내에서도 잘 알려져 있고 이러한 불포화 사면에서의 수리학적/역학적 거동은 매우 복잡하다. 불포화사면에 대한 해석 수행 시, 함수특성곡선은 매우 중요한 지반정수로 활용되고 있는데 풍화사면의 경우 층으로 구성되어 있고 상재하중을 받고 있어 함수특성곡선의 적용시 적절한 상재하중의 효과에 대한 고려가 필요하다. 이러한 상황을 반영하기 위하여 본 연구에서는 풍화토를 대상으로 다양한 조건의 상재하중하에서 함수특성곡선을 획득하였으며 이를 통하여 불포화전단강도를 추정하였다. 또한 상재하중의 영향을 고려하여 불포화풍화사면에 대한 안정성을 평가하였다. 해석 결과 상재하중에 대한 효과는 매우 중요하며 적절한 해석에서의 적용은 사면안정성 예측은 항상 시킬 수 있다고 판단된다.

• 한국농공학회지
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• 제39권4호
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• pp.82-89
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• 1997

A physically-based soil-water erosion model with simple hydrology and Rose & Hairsine's erosion concept is described, and was implemented in the form of computer program. The model derived from the concept of stream power(Bagnold, 1977) considers settling velocity characteristics of the soil and distinguishes between the processes of entrainment and re-entrainment. It deals separately with rill flow and sheet flow, handles vegetation in terms of soil contact cover, and has the ability to simulate soil movement on nonuniform slopes. The model predicted sediment concentrations reasonably with the results of Mclsaac et al. (1990). It showed a capability to quantitatively predict the movement of soil on uniform and nonuniform slopes. Among the model parameters, soil depositability $({\phi})$ was the most sensitive from the sensitivity analysis.

• 한국환경복원기술학회지
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• 제10권4호
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• pp.95-108
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• 2007

Test application of revegetation measure was made on the roadside slope damaged by Nongseo-Eomo national road improvement project in a bid to prevent the soil from being washed out as well as to restore the ecological environment, and the survey for assessment of the effect of slope revegetation measures was conducted, beginning May 11 through Nov 7, 2006. In the wake of comprehensive reviewing and evaluating the surrounding topographic environment, physical and chemical characteristics of soil, germination of revegetation plants, analysis of bio mass, covering ratio and the plants appeared, measure b was found to have been most appropriate to cut blasting rock slope, and alternatively measure c. For cut ripping rock slope, measure c-1 appeared to be effective in revegetation effect, and alternatively, b-1.When it comes to cut soil slope, measure c-2 was found to be effective, and b-2 to be a good alternative. And for embankment soil slope, measure b-3 appeared to be most efficient in revegetation effect and measure f as alternative.

• Geomechanics and Engineering
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• 제34권4호
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• pp.341-380
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• 2023

This study evaluates the seismic fragilities in fill slopes in South Korea through parametric finite element analyses that have been barely investigated thus far. We consider three slope geometries for a slope of height 10 m and three slope angles, and two soil types, namely frictional and frictionless, associated with two soil states, loose and dense for frictional soils and soft and stiff for frictionless soils. The input ground motions accounting for four site conditions in South Korea are obtained from one-dimensional site response analyses. By comparing the numerical modeling of slopes using PLAXIS^2D against the previous studies, we compiled suites of the maximum permanent slope displacement (D_max) against two ground motion parameters, namely, peak ground acceleration (PGA) and Arias Intensity (I_A). A probabilistic seismic demand model is adopted to compute the probabilities of exceeding three limit states (minor, moderate, and extensive). We propose multiple seismic fragility curves as functions of a single ground motion parameter and numerous seismic fragility surfaces as functions of two ground motion parameters. The results show that soil type, slope angle, and input ground motion influence these probabilities, and are expected to help regional authorities and engineers assess the seismic fragility of fill slopes in the road systems in South Korea.

• 한국지반공학회논문집
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• 제18권5호
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• pp.27-35
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• 2002

원 지반을 성토하여 인공적으로 형성된 다짐지반에 터파기를 하여 관을 매립하거나, 암거를 설치하는 작업을 수행 하는 경우가 자주 있다. 이 때 조성되는 임시굴착사면의 기울기를 적용함에 있어서 실험이나 사면안정해석 등의 적절한 과정을 수행하지 않음으로 인해 사면붕괴가 발생하여 인명 피해는 물론이고 공기의 지연 및 공사비의 증액 등 크고 작은 손실을 초래하고 있다. 본 논문에서는 이러한 임시사면의 안정성 검토를 위해 대표적인 경우들에 대한 사면안정해석을 수행하였으며, 특히 사면안정에 대한 다짐지반의 비등방성에 따른 전단강도의 영향을 검토하였다. 해석에서 적용한 다짐지반의 비등방성 전단강도는 전단면과 다짐층 간의 경사를 변화시키면서 수행한 일련의 직접전단시험으로부터 추정하였다. 해석 결과, 비등방성을 고려하는 지의 여부에 따라서 임시사면의 적절한 안정기울기가 소폭으로 변화할 가능성이 있음을 알았다. 그러나, 이에 따른 안전율의 변화나 파괴면의 양상은 그리 크게 변하지 않는 것으로 나타났다.

• 한국지반공학회논문집
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• 제21권8호
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• pp.95-105
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• 2005

토목섬유로 보강된 성토사면에 대한 사면안정해석은 보강재의 효과를 고려하여 수정된 한계평형해석법을 사용하는 것이 일반적이나, 대부분의 경우 보강재에 의하여 활동면상에 증가된 전단저항력만을 고려함으로써 전체 활동토체의 평형조건의 만족여부는 확실치 않다. 일반적으로 사면안정해석은 활동면상의 법선응력의 분포를 구하는 것으로 귀결 되므로, 본 연구에서는 활동면상에 작용하는 법선응력의 분포를 수평방향의 거리 $\chi$에 대한 2차함수로 가정하여 보강재의 효과를 고려하면서 힘과 모멘트의 평형조건을 모두 만족하는 새로운 사면안정해석법을 제안하였다. 제안된 사면 안정해석법은 잘 알려진 보강 및 무보강 사면에 대한 사면안정해석 사례와 보강토 옹벽 및 보강사면에 대한 모형실험 결과에 대한 해석을 통하여 그 타당성을 검토하였다. 그 결과 본 연구에서 제안한 방법은 보강 및 무보강사면에 대하여 타당한 사면활동에 대한 안전율을 제공해주는 것으로 나타났다.