칼럼 - "산사태 예방을 위한 산림관리 전략"

차두송,Cha, Du-Song 한국방재협회 2016 방재저널 Vol.18 No.1

임도(林道) 절토사면(切土斜面)의 붕괴위험(崩壞危險) 예측(豫測)에 관한 연구

차두송,지병윤,Cha, Du Song,Ji, Byoung Yun 강원대학교 산림과학연구소 1998 Journal of Forest Science Vol.14 No.-

본 연구는 집중호우로 인하여 임도사면 붕괴가 발생한 강원도 춘천시 지역의 5개 임도(백양임도, 변가터임도, 사오랑임도, 부귀임도, 당림임도)를 대상으로 수량화이론(II)에 의한 절토사면의 붕괴위험 예측에 관하여 분석하였다. 그 결과는 다음과 같다. 임도 절토사면 붕괴는 주로 절토부 구조적인 요인과 식생, 지형적인 요인이 복합적으로 작용하여 발생하는 것으로 나타났다. 또한 편상관계수(partial correlation coefficient) 및 범위(range) 값에 의한 절토사면의 붕괴예측 결과는 절토길이 8m이상, 토심이 2.5m이상, 산지경사 $30^{\circ}{\sim}50^{\circ}$사이, 절토피복율이 무식생인 경우, 절토경사 $60^{\circ}$ 이상에서 붕괴위험도가 높게 나타났으며, 판별적중율은 90.1%이었다. On the basis of data obtained from 5 forest roads(Backyang, Byongatae, Saorang, Bukyu and Dangrim forest road) collapsed under a heavy rainfall in Chunchon, Kangwondo, this study was carried out to predict the cutting slope failure of forest road by using Quantification theory(II). The results were summarized as follows; The cutting slope failure was chiefly occurred by correlated action of road structure, vegetation and topographical factors. The cutting slope failure predicted by partial correlation coefficients and range values was characterized by longer than 8m of cutting slope length, depper than 2.5m of soil depth, between $30^{\circ}$ and $50^{\circ}$ of original ground slope gradient, absence of vegetation coverage on cutting slope, and greater than $60^{\circ}$ of cutting slope gradient. And the rate of correct discrimination by analysis of cutting slope failure was 90.1%.

임도개설에 따른 삼림시업의 실태해석 및 효과분석

차두송,지병윤,김경남,최인화 ( Du Song Cha,Byung yun Ji,Kyoung Nam Kim,In Hwa Choi ) 한국산림과학회 1998 한국산림과학회지 Vol.87 No.2

Based on forestry inventory data and various informations, this study was conducted to analyze the silvicultural activities by distance classes from forest road and to evaluate their effects in the area of Mt. Gari managed by Chunchon Regional Office of Northern Forest Management Office. The results were summarized as follows; 1) Most ㏊rvesting practice(67.9%) was done within 500m from forest roads, in the order of Pumgul, Saorang, and Kongkol forest road. And thinning practice was not related to the distance from forest road, produced 440.6㎥, 35.7% of total thinning volume within 1,000m width along the forest roads. 2) Planting of 530,461 seedlings, 66.8% of total planting stock, in 176.9㏊, 66.6% of total area within 1,000m from forest road, and supplementary planting of 46,243 seedlings was done in 15.4㏊, 42.9% of total area within 500m from forest road. Areas and numbers of seedlings of two planting practices were in the order of Pumgul and Byungatur forest road. 3) Tending operation was done in 330.0㏊, 60.3% of total area within 500m from forest road, and pre-commercial thinning was done in 693.6㏊, 71.2% of total area. Areas of intermediate cutting practices were in the order of Pumgul, Korkol, and Saorang forest road.

수량화 II 류에 의한 임도절토사면의 붕괴요인 평가

차두송,지병윤,Cha, Du-Song,Ji, Byoung-Yun 강원대학교 산림과학연구소 2001 Journal of Forest Science Vol.18 No.-

본 연구는 집중호우로 인하여 절토사면의 붕괴가 발생한 임도를 대상으로 수량화이론(II)을 이용하여 붕괴요인을 평가하였다. 그 결과는 다음과 같다. 임도 절토사면의 붕괴발생에 미치는 요인의 영향은 절토사면길이, 겉보기 토질, 사면방위, 절토사변경사, 산지경사 등 5개 요인이 가장 크게 나타났다. 특히, 절토사면길이는 8m 이상, 겉보기 토질은 토사, 사면방위는 북사면, 절토사변경사는 $60^{\circ}$이상, 산지경사는 $35{\sim}40^{\circ}$ 사이에서 사면붕괴에 기여도가 가장 크게 나타났다. On the basis of data obtained from forest road collapsed due to a heavy rainfall, this study carried out to evaluate the cutting slope failure factors of forest road by using Quantification theory(II). The results were summarized as follows. The factors on cutting slope failure was ranked in the order of cutting slope length, soil type, aspect, cutting slope gradients and slope gradients. And the slope failure was mainly occurred under such conditions as cutting slope length longer than 8m, soil type with soil, aspect of N, cutting slope gradients steeper than 600 and slope gradients greater than $35{\sim}40^{\circ}$.

춘천(春川) 가리산(加里山) 지역(地域)의 임도(林道) 성토사면(盛土斜面)의 토질역학적(土質力學的) 특성(特性)

차두송,전근우,지병윤,오재헌,Cha, Du Song,Chun, Kun Woo,Ji, Byoung Yun,Oh, Jae Heun 강원대학교 산림과학연구소 1999 Journal of Forest Science Vol.15 No.-

This study was carried out to analyze the mechanical properties of soil for counterplan of recovery construction and the slope stability on fill slope of Sang-gul forest road in Mt. Gari. To analyze the mechanical properties of apparent soil on fill slope in forest road, various soils such as soil, gravelly sandy soil, weathered rock were used as experimental sample in this study. In each experimental sample, particle size distribution test, liquid limit test, plastic limit test, and specific gravity test were carried by Korean industrial standards(KS F 2302, KS F 2303, KS F 2304, KS F 2306, KS F 2308). Through the results of soil particle size distribution analysis, soil moisture content analysis, and specific gravity analysis, soil texture, uniformity coefficient, curvature coefficient, dry density and specific gravity were able to be determined in sampling site. As a results in this study, soil was classified as SP, SW, GP by Unified Soil Classification Standard (USCS). specific gravity and dry unit weight of soil have the value range of 2.52~2.60 and 1.39~1.43, respectively. Also plastic index showed non plastic condition. 본 연구는 춘천 가리산 지역의 상걸임도를 대상으로 성토사면의 토질력학적 특성을 파악하여 사면안정해석 및 대책공법의 수립을 위한 기초자료를 제공하고자, 겉보기 토질분류기준인 토사, 호박돌토사, 풍화암 사면에서 토사를 채취하여 시험을 실시하였다. 각 토양시험으로부터 흙의 입도분석(KS F 2302), 흙의 액성한계시험 (KS F 2303), 흙의 소성한계시험(KS F 2304), 흙의 함수량시험(KS F 2306), 흙의 비중시험 (KS F 2308)을 실시하였다. 또한 각 사면에 대해 흙의 입도분석을 통하여 입경분포, 균등계수, 곡률계수를, 흙의 함수량시험과 흙의 비중시험을 통하여 흙의 건조밀도와 비중을 산출하였다. 그 결과, 통일분류법에 의한 토질분류는 SW, SP, GP로, 건조밀도는 $2.52{\sim}2.60g/cm^3$, 비중은 1.39~1.43으로 나타났으며, 소성지수는 비소성 상태인 것으로 나타났다.

수량화(數量化)II류(類)에 의한 임도(林道) 성토사면(盛土斜面)의 붕괴요인(崩壞要人) 평가 (評價) 및 예측(豫測)

차두송,지병윤,Cha, Du Song,Ji, Byoung Yun 한국산림과학회 1999 한국산림과학회지 Vol.88 No.2

본(本) 연구(硏究)는 집중호우로 인하여 임도재해가 발생된 강원도(江原道) 춘천지역(春川地域)의 5개 임도(林道)를 대상으로 임도구조요인 4항목과 입지요인 4항목을 이용하여 수량화(數量化)II류(類)에 의한 임도성토사면(林道盛土斜面)의 붕괴요인(崩壞要因) 평가(評價) 및 예측(豫測)을 실시하였다. 그 결과는 다음과 같다. 임도구조요인(林道構造要因)인 종단(縱斷)물매는 $2^{\circ}$ 이하 및 $4^{\circ}$ 이상, 유하거리(流下距離)는 80m 이상, 성토사면(盛土斜面)길이는 6m 이상, 성토사면경사(盛土斜面傾斜)는 $35^{\circ}$ 이상에서 성토사면의 붕괴위험도가 높은 것으로 나타났으며, 임도입지요인(林道立地要因)인 임도노선위치(林道路線位置)는 능선부, 사면구성물질(斜面構成物質)은 풍화암과 연암, 산지경사(山地傾斜)는 $35{\sim}45^{\circ}$, 사면종단면형(斜面縱斷面形)은 철(凸)형과 요(凹)형 사면에서 붕괴위험도가 높은 것으로 나타났다. 또한 사면붕괴에 영향을 미치는 인자는 성토사면길이, 사면구성물질, 임도노선위치 등의 순으로 나타났으며, 판별적중율(判別的中率)은 86.5%로서 높은 적중률을 나타냈다. 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%.

기계화 집재작업을 (集材作業) 위한 노망정비에 (路網整備) 관한 연구 (Ⅱ) - 적정임도간격 및 임도밀도 (林道密度) -

차두송(Du Song Cha),조구현(Koo Hyun Cho) 한국산림과학회 1994 한국산림과학회지 Vol.83 No.3

This study was carried out to examine the optimal road spacing and road density to minimize the total harvesting cost(road construction cost plus yarding cost) for mechanized yarding system to roadside by one - and two-stage two-way in Forestry build-up region. Chunchon-kun, Kangwon-do. The estimated road construction costs were ranged from ten million won to sixty million won per km. The results have indicated that cable crane was appropriate for yarding machine by one-stage, two-way, and estimated optimal road spacing was 1,698m-4,192m, averaged 3,087m, ;end road density was 3.44m/㏊-8.44m/㏊, and averaged 5. 12m/㏊. In hilly terrain, combination of medium yarder and Logging bogie was suited to yarding machine by two-stage, two-way, and calculated optimal road spacing was 1, 483m-3, 481m, averaged 2, 589m, and road density was 4.05m/㏊-9.46m/㏊, averaged 5.90m/㏊. In steep terrain, combination of medium yarder and jinsung winch was suited, and estimated optimal road spacing was 1,693m-3,982m, averaged 2, 960m, and road density was 3.68m/㏊-8.64m/㏊, averaged 5.38m/㏊.

최적임도배치계획에 관한 연구

차두송(Du Song Cha),이준우(Joon Woo Lee) 한국산림과학회 1992 한국산림과학회지 Vol.81 No.2

A planning method of optimum forest road was tested in the compartment II of Kangweon National University Forests by using a digital terrain model under four evaluation factors, i. e., minimum road length, average skidding distance, exploitative index, and ratio of inaccessible points. The results of the study were as follows : 1. Optimum forest road design based on the minimum road length was shown as 6035.6m, 12.73m/㏊, 279.9m, 1.43, and 15.7% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively. 2. Optimum forest road design based on the average skidding distance was shown as 7828.5m, 16.52m/㏊, 198.4m, 1.31, and 4.0% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively. 3. Optimum forest road design based on the exploitative index was shown as 7410.6m, 15.64m/㏊, 210.9m, 1.26, and 5.0% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively. 4. Optimum forest road design based on the ratio of inaccessible points was shown as 8307.1m, 17.53 m/㏊, 184.9m, 1.29, and 2.5% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively.

Fuzzy 이론을 이용한 임도사면의 붕괴하능성 평가 ( 1 )

차두송(Du Song Cha),지병윤(Byoung Yun Ji),오재헌(Jae Heun Oh) 한국산림과학회 2000 한국산림과학회지 Vol.89 No.1

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°, fill slope length greater than 8m, fill slope gradients steeper than 40°, road on ridge position, soil types with weathered rock, slope gradients steeper than 40°, 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%.

수량화 2류에 의한 임도 성토사면의 붕양요인 평가 및 예측

차두송(Du Song Cha),지병윤(Byoung Yun Ji) 한국산림과학회 1999 한국산림과학회지 Vol.88 No.2

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° or more than 4°, distance of surface-flow longer than 80m, fill slope length greater than 6m, and fill slope gradients steeper than 35°. 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° to 45°, 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%.