• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.4
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• pp.43-51
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• 2003

The purpose of this study was evaluate to the stability on cut slope of forest roads by forest environmental factors. The total of 19 environmental factors on cut slope of forest roads were investigated in about 42.74km constructed during 1987 to 1993 in Gyeongnam and Jeonnam province. The evaluation of slope stability in forest roads were conducted by the discriment analysis. The main factors influencing the stability of cut slope were significant in order of coverage, soil hardness, degree of slope, altitude, silt loam, convex(凸) and compound(凹凸). The centroids value of discriminant function in the stability and unstability area estimated to -1.194 and 1.127, respectively. The boundary value between two groups related to slope stability was -0.072. The prediction rate of discriminant function for stability evaluation of was as high as 90.4%.

• Journal of Soil and Groundwater Environment
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• v.18 no.5
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• pp.15-25
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• 2013

In this study, two kinds of soil-based proficiency testing materials (PTMs), NICE-012L and NICE-012R were prepared and certified for Benzen, Toluene, Etylbenzene and Xylene with evaluation of uncertainties. In order to analyse BTEX (Benzen Toluene Etylbenzene Xylene) for the candidate materials, GC/MS was used after pretreatment according to methods of soil analysis by Ministry of Environment. For the homogeneity test among bottles in terms of candidate materials, ISO 13528 and IUPAC Protocol were used and according to the result, both candidate materials showed sufficient homogeneity. Also, the stability test over the candidate materials was accessed according to the ISO Guide 35 by classifying short-term and long-term stability and the result showed that both candidate materials showed decent stability. The reference values of the two candidate materials depending on BTEX components were derived from the average of the 11 samples that were used for verification of the samples' homogeneity. Uncertainty of measurement was combined by uchar that was caused by a characteristic value, $u_{bb}$ that was caused by between-bottle homogeneity, and $u_{stab}$ that was caused by stability, and then combined uncertainty ($u_{PTM}$) was multiplied to the coverage factor (k) derived from the effective degree of freedom from each factor that leads to expanded uncertainty (U) in about 95% of confidence level. The proficiency testing materials developed through this study were supplied to National Institute of Environmental Research (NIER) and utilized as an external proficiency testing materials for evaluating analysis capacity of soil agencies with specialty in terms of soil analysis approved by Minister of Environment.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.1
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• pp.94-102
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• 1999

The retaining wall is a structure which was made for changing land form in many construction. The first role of the retaining wall is to maintain the slope stability. But recently, the amount of retaining wall have been increasing because of the expansion of construction works and the amenity of urban environment have been decreasing because of environmental destruction and the scenic heterogeneity. So we should consider the slope stability and ecological stability at the same time. The purpose of this study is to develop the retaining wall revegetation technology using the Eco-Stone, the structure of co-satisfying which included the slope stability and the revegetation effect. Eco-Stone is a structure which has high stability for earth pressure, settlement and drainage. And cost and term of construction works also have been decreased. Eco-Stone structure is one of factors composing the ecological network which is harmonize with surrounding environment. In this way, it is expected that the ecological habitats of various species would be restored.

• Economic and Environmental Geology
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• v.33 no.2
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• pp.117-128
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• 2000

Regional evaluations of slope stability by the failure criterion and by environmental geological factors were conducted. The failure criterion is the general conditions for plane failure which consider the geometrical conditions between geological discontinuities and topographical slope planes. The factor focused in this condiction is dip and dip direction. Geostatics, named semivariogram was used for establishing structural domains in slope stability evaluation by the failure criterion. The influential range was calculated to 6 km in the case of dip direction of dominant joint set and 7 km in the case of dip of the same dominant joint set. Then applying this failure criterion to the study area produced a slope stability map using the established domains and slopes generated by TIN module of ARC/INFO GIS. This study considered another regional slope stability analysis. 5 failure-driven factors 9the unstable slope map, geology, engineering soil, groundwater, and lineament density) were selected and used as data coverages for regional slope stability evaluation by geoenvironmental factors. These factors were weighted and overlayed in GIS. From the graph of cumulatave area (%) and instability index, finding critical points classified the instability indices. The most unstable slopes are located in the southern area of Mt. Eorae, Dabul-ri, and the eastern area of Junkok-ri in the first area is plane failure. Also, the expected orientations of failure are 59/338 and 86/090 (dip/dip direction).

• Economic and Environmental Geology
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• v.29 no.5
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• pp.615-622
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• 1996

Slope stability analysis was conducted using remote sensing and Geoscientific Information System (GIS) as a part of natural hazard assessment around Chungju area. Landsat TM band 5 and 7 which contain more information about geological structure and geography are chosen and processed to analyse regional geological structure. Through image processing technique such as PCA, HFF, edge detection and enhancement, regional lineament can be mapped and identified. The lineament density map is constructed based on summed length of lineaments per unit area and the study area can be divided into 7 structural domains. Various factors of slope stability analysis such as geology, slope aspect, degree of slope, landcover, water shed as well as characterized structural domain are constructed as a database of GIS. Rating and weighting of each factor for slope stability analysis is decided by considering environmental geological characteristics of study area. Spatial analysis of regional slope stability is examined through overlaying technique of the GIS. The result of areal distribution of slope stability shows that the most unstable area is all over Jaeogae-ni, Hyangsan-ni and Mt. Daedun.

• Journal of Ocean Engineering and Technology
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• v.20 no.5 s.72
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• pp.70-76
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• 2006

A Probabilistic neural network (PNN) technique for predicting the stability number for the armor blocks of breakwaters is presented. A PNN is prepared using the experimental data of van der Meer and is then compared with the empirical formula and previous artificial neural network (ANN) model. This comparison shows that a PNN can effectively predict the stability numbers in spite of data complexity, incompleteness, and incoherence, and can be an effective tool for the designers of rubble mound breakwaters to support their decision process and to improve design efficiency.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.511-518
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• 2000

Characteristics of joint orientation, length, spacing and their distribution are very important factors for slope stability, Especially, the effect of joint spacing is an essential factor of slope stability. This study is to analyze the effect of joint spacing in cases of sliding and toppling, which is a typical failure mode. Joint spacing can divided into vertical spacing(spacing) and horizontal spacing(gap). And then, the spacing/length ratio of joint directly affect rock slope failure. When the ratio is below 0.05, the possibility of failure is rapidly increased. In case of toppling, the possibility of failure depends on the ratio of spacing to height of slope ratio slope. As the ratio decreases, the possibility of toppling failure increased. The critical ratio of spacing to height of slope is determined by the dip angle of the slope and the orientation of joint sets.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.269-272
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• 2007

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• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.325-326
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• 2007

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• Journal of Korean Society for Atmospheric Environment
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• v.6 no.2
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• pp.168-175
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• 1990

Pasquill stability class (PSC) was evaluated with Monin-Obukhov length (L) using the data observed at a height of 213m meteorological tower in Tsukuba, Japan. PSC was determined with wind speed and insolation (net radiation at night), and L was calculated with the heat flux and the friction velocity obtained at 25m by the eddy correlation method. To evaluate PSC with L, for every class of Pasquill stability (from A to F class), percentiles and median of L were used. Results show that for every class of Pasquill stability, L varies so widely that PSC does not adequately represent the atmospheric stability conditions. The scheme which estimates L using air temperature at two levels and wind speed at single level was developed. Comparison between estimated L by the scheme and observed L reveals that the scheme is better than PSC. Furthermore, the scheme is more advantageous than PSC because it uses air temperature at two levels instead of insolation which is more difficult to observe in the field than air temperature.