• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.626-631
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• 2006

본 연구는 2006년 7월 집중호우에 의해 많은 인적.물적 피해가 발생한 강원도 지역의 피해 현장을 조사하였으며, 그 중 성토사면붕괴를 붕괴유형별로 구분하고 발생원인과 특성을 분석하여 그에 따른 적절한 대책방안을 제시하였다. 집중호우에 의한 성토사면의 붕괴유형 중 토석류에 의한 도로횡단 배수구조물의 기능상실로 유수가 노면으로 침출되고 수압이 발생하여 도로가 유실된 유형과 하천선형 불량으로 만곡수충부(물이 직접 부딪히는 부분)에서 유속이 빨라져 세굴에 의한 붕괴가 전체성토붕괴사면의 83%를 차지하였다. 이에 대한 대책방안으로는 토석류를 계곡상부에서 부터 예방할 수 있는 방법으로 사방댐 및 그물망 공법 등이 좋은 대책방안이 될 수 있으며, 토석류에 의한 유송잡물을 모두 통과할 수 있도록 충분히 큰 배수시설을 설치하는 방법도 좋은 대책방안이 될 수 있다. 무엇보다 열대성 국지 폭우를 이제 일상의 한반도 기후현상으로 받아들여 주먹구구식의 일회성 대책방안을 지양하고 바뀐 강우특성과 빈도를 고려하여 계획 홍수위를 재산정하고 그에 따라 하천정비계획을 재검토해야 할 것이다.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.324-330
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• 2001

This study was carried out to develop prediction model for fill slope failure of forest road in igneous rock area using fuzzy theory which is non-linear model. The results were summarized as follows. The importance weight of factors on fill slope failure was ranked in the order of fill slope length, fill slope gradient, soil type, aspect, road position and longitudinal slope form. The degree of potential slope failure was high mainly under the such conditions as fill slope length greater than 8m, fill slope gradients steeper than $40^{\circ}$, constituent material with weathered rock, aspect of NE and road on ridge position. The optimal prediction model was developed with 0.15 of optimal coefficient(c) and 3.1165 of ${\lambda}$-value when fuzzy integral value of slope failure possibility is more than 0.5. And the discriminant accuracy was 86.8%, which shows the high availability for discrimination.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.33-40
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• 2000

This study was carried out to evaluate the fill slope failure possibility of forest road in Metamorphic rock area using fuzzy theory which is non-linear model. The results were summarized as follows. The potential slope failure by nine factors was mainly occurred under the such conditions as the total road width ranging from 4m to 5m, longitudinal gradients below $2^{\circ}$, fill slope length greater than 8m, fill slope gradients steeper than $40^{\circ}$, road on ridge position, soil types with weathered rock, slope gradients steeper than $40^{\circ}$, aspect of NW, and longitudinal slope form in convexity. The weight of importance by factors on fill slope failure was ranked in the order of fill slope length, fill slope gradient, road position, soil type, aspect and longitudinal slope form. The analysis showed that the fill slope failure possibility was low with less than 0.485 of the fuzzy integral value and high with more than 0.620 of the value. And the discriminant accuracy was 74.6%. The analysis with six out of nine factors indicated that the possibility was low with less than 0.441 of the fuzzy integral value and high with more than 0.583 of the value. In this case, the discriminant accuracy was slightly increased to 78.0%.

• Journal of Forest and Environmental Science
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• v.7 no.1
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• pp.35-41
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• 1990

This study was conducted to find out the suitable gradient and length of the slope from the landslide of banking slope and cutting slope caused by rainfall. The survey was carried out on forest road built in 1986. And the period of survey was from June, 1989 to August, 1989 after dividing the forest road into A and B. The survey plots consisted of the 12 banking slopes and 6 cutting slopes. The results obtained from the study were summarized as follows; 1. The rate of landslide appeared 75% in A forest road, 50% in B forest road, and then the average 67% in A and B forest road. But the value of landslide showed considerably low. 2. Because of landslide chiefly occuring on banking slope of $36^{\circ}{\sim}38^{\circ}$ and on cutting slope of $42^{\circ}{\sim}43^{\circ}$, it is suitable to decide the banking slope and cutting slope below each $36^{\circ}$ and $40^{\circ}$. 3. Landslide was the same on banking slopes through the length of slope. The best suitable length of slope is below 4m in cutting slope.

• Journal of the Korean GEO-environmental Society
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• v.5 no.3
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• pp.41-50
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• 2004

The study of seepage behavior is very important to slope stability of road landfill for heavy rainfall season. This study is done to propose more stable of road landfill based on analysis of seepage behavior and slope stability for some cases of road landfill. The selected sections of collapsed road landfill are most general case of road landfill, a case is landfill on the ground area and another case is on the slope area. The results of this study is summarized as follows. It is founded that the road landfill on the ground area is increased saturation region due to rainfall infiltration, and the seepage behavior of road landfill is solved by theory of unsaturated flow. The road landfill is more unstable due to rainfall infiltration at the slope surface, especially during heavy rainfall. The case of road landfill on the slope area is analyzed in consideration of slope surface infiltration, and it is founded that the slope instability is increased because of rainfall infiltration. The drain layer located on the original ground which made by more permeable materials could be good action of slope stability in the case of road landfill on the slope area.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.240-248
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• 1999

On the basis of data obtained from five forest roads collapsed due to a heavy rainfall of 1995 in Chunchon, Kangwon-do, this study was carried out to evaluate and predict the fill slope failure of forest roads with four factors of forest road structure and those of location condition by using Quantification theory(II). The results were summarized as follows ; In the structure factors of forest road, the fill slope failure was mainly occurred in longitudinal gradients less than $2^{\circ}$ or more than $4^{\circ}$, distance of surface-flow longer than 80m, fill slope length greater than 6m, and fill slope gradients steeper than $35^{\circ}$. In the factors of location condition, the failure was mainly occurred in ridge portion of road position, weathered rock and soft rock of constituent material, slope gradients in the range from $35^{\circ}$ to $45^{\circ}$, and concave and convex of longitudinal slope forms. The priority order for factors influencing on fill slope failure was ranked by fill slope length, constituent material, road position, and so on. And the rate of correct discrimination by analysis of fill slope failure was estimated at the high prediction of 86.5%.

• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.581-587
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• 2007

작년 7월 태풍 에위니아와 집중적인 호우는 강원도 지역에 많은 피해를 주었으며, 특히 강원도 인제, 양양, 평창 등의 지역에서 수십 명의 인명피해와 재산피해를 발생시켰다. 이로 인해 집중호우로 인한 사면 붕괴 및 산사태, 토석류 발생사례 및 하천과 인접한 도로 성토사면 붕괴 사례 등의 조사가 실시되고 수집된 자료를 분석, 문제점 제시 및 많은 대책방안들이 도출되었다. 이에 본고는 작년 수해현장들을 다시 찾아 수해복구 방법들을 조사하였으며, 수해복구사례를 소개함으로써 매년 여름철 발생되는 집중호우에 의한 자연재해 예방에 몸 담고 있는 관련자 및 토목기술자들에게 수해 저감 및 대책방안에 대한 일례를 전하고자 한다.

• Journal of Korean Society of Forest Science
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• v.76 no.2
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• pp.161-168
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• 1987

Forest road (10 Km) constructed for the demonstrational purpose by Forest Work Training Center (F.T.C.) in 1984 was partly damaged through the roadside landside and ditch erosion by the typhoon in 1986. The causes were investigated to apply for protecting against the damage of mountain forest road. The damaging length caused by roadside landside is around 3% out of total length of 10 Km forest road, and mostly coming from the curve road filled up more than 10 m slope length on the concave mountain slope, partly from the foot of fillslope along the ever-following valley and from the both side of fillslope under the outlet of culvert with ever-flowing water. In case of ditch erosion, the big damage at V-type ditch is coming from the overflow of valley water flowing down along the inside slope. Other problem is also showing in the steepness of longitudial gradient, which is felt as a problem in road to be constructed under more than 10 persent of gradient. Other cause of ditch erosion is coming from the bury of sand basin (water collecting wall) by the debris in small diameter culvert zone, namely less than 400mm, in diameter and by the soil mass slumped down from steep wall slope. From above results the causes of F.T.C. model road damage is showing to come from no-following the general guide or little experience to protect against the forest road damage. When improved above mentioned mistakes, F.T.C. Method of mountain forest road type could be developed as a model of Mountain forest road.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.354-365
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• 1993

The purpose of this investigation is to point out the physical fixation and stability of banking slopes of forest roads by invasion of trees. We investigated the situations of sediment discharge and coverage of invaded trees at banking slopes of forest roads. The coverage of invaded trees were calculated from crown injection based on the stable slope and was compared with length of slope, slope gradient, and passage years after construction of forest road. 1. We investigated on the sediment discharge and the invasion of trees at banking slopes, which were actually observed 8 forest roads of Kyonggi-Do and Kangwon-Do. 2. There was no physical stability of the banking slope due to the surface erosion and slope failure, but the tree invasions were active at the stable plots. 3. The length of slope was constructed to 4.0m to 61.0m and recent forest road was mainly constructed to the slopes longer than 30m. There was strong regional effect between the length of slope and the coverage of invaded trees and the above two factors were inversely proportional to each other. 4. There was no significant relationship between the slope gradient and the coverage of invaded trees and the slope constructed within the angle of repose showed the relatively high coverage of invaded trees. 5. There was no significant relationship between the passage years and the coverage of invaded trees in the same investigative region after the construction of forest road. But there was a gradually increasing relationship of tree invasion between above two factors. However, there was some limitation to expect the invasion of the tree species. 6. In the light of the above results, we suggest that the construction of forest road may need foundation work and vegetation work simultaneously for the physical stability to make the environment of tree plantation and that the reasonable increase of construction cost of forest road may be prior to the other factors.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1383-1387
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• 2005

사면의 식생이 초기에는 강우에 의해서 표면흐름, 지하수위 증가, 지표수의 침윤에 의해서 성장이 될 수 있으나, 시간이 경과함에 따라 식생에 의한 사면의 안정성을 확보 하는 데에는 큰 영향을 미치지 못한다. 즉, 사면의 식생을 복우언시켜 식물근(뿌리)에 의해서 사면을 안정화 시키기 위해서는 사면의 위치, 고도 및 방향 등에 따라 적응할 수 있는 식물의 선택과 성장에 충분한 수분을 보습할 수 있는 구조의 사면계획과 구조물 설치가 필수적이다. 본 연구에서는 절$\cdot$성토면에서 경사면의 붕괴를 방지하고 식생을 복원하는 방법으로 Mattress Gabion을 제안하였다. 정형화되고 유연성 있는 다공성 Mattress 구조를 통한 식생의 복원은 사면의 안정과 환경친화적인 목적을 모두 만족할 수 있었다. 특히, Gabion 근고공이 설치된 이후에 공극이 큰 Mattress 구조물을 중심으로 식물의 뿌리를 지반에 직접 연결하거나, 식생 활착이 어려운 암반 절취 사면에서도 Mattress 옹벽을 통해서 식물이 양질의 흙에 직접 활착할 수 있도록 설계한 사면 Mattress의 경우는 사면의 안정성 증대와 아울러 지하수의 표면흐름과 투수 및 침윤에 의한 식물의 성장피해를 최소화하고 시간이 지날수록 식생에 의해서 Mattress Gabion 옹벽이 내구성과 유연성을 유지할 수 있었다.