• The Journal of Engineering Geology
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• v.22 no.2
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• pp.223-231
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• 2012

Many cut slopes are located near national highways, resulting in large annual damage to infrastructure from the collapse of cut slopes. Therefore, to effectively maintain cut slopes, high-risk slopes should be identified and monitored. In this paper, we evaluate the effectiveness of the management of cut slopes using the risk score calculated from cut-slope inventory data. The inventory survey, as a simple assessment of the characteristics of various slopes, was performed to collect basic data that could be obtained visually in the field for the management of cut slopes. This method is not a precise survey, and it was composed of the general status and characteristics of cut slopes, the inspector's assessment, and inventory data in order to estimate a risk score for each slope. In this paper, we calculated the risk score by investigating the present status of cut slopes adjacent to 10,461 national roads. In order to evaluate the effectiveness of using risk score data, we compared the score for stable slopes with those of failed cut slopes. Failed cut slopes occurred in sections with the highest risk score. The results show that risk score derived from the inventory survey of cut slopes are useful in the management of cut slopes with risk of failure and in monitoring large numbers of cut slopes.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.6
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• pp.63-76
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• 2016

Slope revegetation refers to the use of vegetation and construction to protect a barren slope devastated by road and building construction. Among many revegetation strategies, hydroseeding has been widely utilized to stabilize barren slopes and has become the representative approach. Previous studies on slope stability have been conducted from a civil engineering perspective, mainly evaluating the stability of cut-slopes on solid bedrock and the use of concrete structures to stabilize devastated slopes. This study was conducted to develop a method to evaluate erosion risk of revegetated cut-slopes, based on criteria derived from previous studies. Twenty-five factors were surveyed on both on-the-spot erosion slopes and non-erosion slopes after slope revegetation to compare slope types. The scores of all non-erosion slopes exceed 80 score while erosion slopes are 80 below. Erosion slopes got the range of 68-74 score while non-erosion slopes got the range of 81-100 score in the first result which was not applied for weighted-values. The scores of all non-erosion slopes exceeded 3.10, while erosion slopes were below 3.10. Erosion slopes were in the range of 2.73-3.09, while non-erosion slopes were in the range of 3.15-3.90 in the second result, which was applied with weighted-values according to the AHP result from a previous study.

• The Journal of Engineering Geology
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• v.10 no.2
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• pp.1-17
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• 2000

In this study, 270 cut-slopes are investigated and statistical analyses are performed. More than 84% of unstable slopes are rock slopes or rock-soil mixed slopes, and 72% of the slopes have 10 to 30 meter in height. And in order to clarify the cause of failure, 3 slopes which have been failed are back-analysed by using the computer programs such as DIPS, UDEC and PCSTABL5M. A heavy rainfall during rainy season is a main cause of slope failure, and a blasting vibration during construction could also give a significant influence on the slope instability.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.63-69
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• 1998

The slope revegetation methods in Korea are generally the hydroseeding mixed with perennial herbs, soil, fibers, and fertilizer in consideration of scenic landscape rather than ecological and engineering effect. But perennial herbs can't protect the slope from deep surface erosion and they are not tall enough to create the original naturalness at the boundary parts of existing woodlands. This study is about the slope revegetation method using nutritional propagation capacity of plants and the experimental construction was carried out on the cut-slope of Yongin Hoam C.C. We dug several trenches to a depth of 80cm and at intervals of 150cm from each other. After placing various kinds of live branches(Salix species) into the trench, we backfilled with the excavated soils and finally sprayed water mixed with soil-stabilizer, fertilizer. As six months passed, we made a vegetation research and check the slope surface erosion. Vegetation research was performed in examining the frequency of each block using transect method. 31 kinds of plant species appeared in total area($113.6m^2$) and the dominant species are Setaria viridis, Artemisia rubripes, Persicaria pubescens, Plantago asiatica, Cyperus amuricus, Commelina communis. Among the examined blocks, '아', the top part of the slope, showed the ratio of 1.4 as the highest Alpha-diversity. With regard to life form, therophytes were shown dominant distribution of 58% of total species and neophytes relatively low distribution of 16%. It can be estimated that there is no ecological stabilization of this slope, because of ruderal species' occupation of 74% in total area. Regarding the slope stabilization, the serious surface erosion didn't take place in spite of heavy rainfall this year, but a little surface erosion took place at the block where no other species coming from outside of the site were found.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.3
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• pp.73-83
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• 2010

A technology using continuous fiber soil reinforcement system for the creation of ecological restoration in a damaged area has been developed and introduced. The continuous fiber soil reinforcement system (Geofiber system) is an environmentally friendly slope protection technique that continuous fiber soil reinforced layers are constructed with green plantation on cut slope. The characteristics of this system in terms of the strength and hydraulic performance, and the vegetation were investigated in this study. The main objectives of this comparative study was to quantify the potential contribution of geofiber system for the revegetation on the cut slope in a damaged area. A Geofiber system was constructed to reinforce the lower layer of slopes and revegetation methods including wood chips were carried out on the upper layer by machineries. The results of monitoring during 3 years on cut slopes were as follows : 1) All the quadrat existed in the proper range for vegetation. 2) Species richness was 4.4 (site-1) and 18.5 (site-2) respectively. 3) The averaged coverage rates of quadrats was 90%. It is remarkable that the continuous fiber soil reinforcement system would be capable of applying to a damaged area and also would serve maintaining a healthier environment for floras. However, it behooves to continue monitoring on succession of vegetation for ecological restoration.

• Journal of the Korean GEO-environmental Society
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• v.8 no.3
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• pp.51-57
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• 2007

In the design of slopes during rainfall, the groundwater level is assumed to be located at the ground surface, based on the change in characteristics of rainfall. In addition, stability investigations are performed for large cut slopes in the design of slopes while standard inclinations specified in the design criteria are applied for the slopes that stability investigations are not performed. In spite of the strengthened criteria of groundwater location, slope failures continuously occur during heavy rainfall, regardless of magnitude of slopes. In order to investigate the cause of the failures, stability investigations have been performed on standard inclination of slopes suggested in the design criteria for both dry and rainfall cases by ground condition in this research. Despite that standard inclination of slopes specified in the design criteria should be stable for both dry and rainfall cases, the results show that standard factor of safety has not been obtained in many cases; more than 50% of total cases for dry cases and more than 65% of total cases for rainfall case. Based on the results, this paper indicates the problems in the current design criteria and proposes the plans for establishment of countermeasure.

• Korean Journal of Environmental Agriculture
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• v.17 no.4
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• pp.358-361
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• 1998

This study was carried out to develop a short term hardening method of tree seedlings of Rhus chinensis Mill., Evodia daniellii Hemsley and Parthenocissus tricuspidata(Sieb. et Zucc.) Planck for afforestation on a concave and a crack of cut-rock slope. The seedlings were grown in a cylinder shaped pot made of polyvinyl net with the soil media of peatmoss, vermiculite, clay, compost, fertilizer, and absorbant(40:25:19:15:1:0.1, v:v). They were cultivated in a greenhouse for four months and in field condition for two months. During the last three months of the growing period the seedlings were hardened by periodic desiccation and irrigation in 4 to 10 days interval. The hardened seedlings showed lower leaf water potential, higher leaf osmotic pressure, and lower T/R ratio than those before the hardening. The hardened seedlings survived well on the soil medium in the concave of cut-rock slope.

• The Journal of Engineering Geology
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• v.22 no.4
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• pp.417-425
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• 2012

CCTV cameras are used for surveillance and purposes of security, and can also be applied for monitoring infrastructure and equipment. In the Cut Slope Management System managed by KICT (Korea Institute of Construction Technology), cut slopes are continuously monitored using a real-time system, with CCTV cameras installed at 119 sites to detect slope activity. Here we compare CCTV images with displacement at three sites and perform a quantitative analysis. Methods for improving CCTV camera management and systems are also discussed with regard to communication, obstacles, and nighttime management.

• The Journal of Engineering Geology
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• v.31 no.1
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• pp.31-42
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• 2021

Database of Cut-slope management system (CSMS) has been constructed based on investigations of all slopes on the roads of the whole country. The investigation data is documented by human, so it is inevitable to avoid human-error such as missing-data and incorrect entering data into computer. The goal of this paper is constructing a prediction model based on several machine-learning algorithms to solve those imperfection problems of the CSMS data. First of all, the character-type data in CSMS data must be transformed to numeric data. After then, two algorithms, i.g., multinomial logistic regression and deep-neural-network (DNN), are performed, and those prediction models from two algorithms are compared. Finally, it is identified that the accuracy of DNN-model is better than logistic model, and the DNN-model will be utilized to improve data-quality.

• Journal of the Korean Geotechnical Society
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• v.24 no.8
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• pp.81-88
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• 2008

In this study, to determine the priority of the effect factors and the preferences of commonly used reinforcing methods for the cut-slope, the reasonable analysis using AHP technique was performed. Analytic Hierarchy Process (AHP) technique is the most widely used method out of all existing decision making methods. On choosing the methods, the most important factor is analyzed to be the stability and durability. Stability, durability and environmental compatibility took up over 50% of the total contributing factors. Cut-slope reinforced method preference with increasing stability method confirmed that concrete retaining wall, reinforced-soil wall and cutting method showed the highest preference rate. Also, in practical field conditions, the cutting method out of four methods was chosen to be the most effective method. This reflected that the methods that are equally superior in all aspects of evaluation factors are more important than the methods with superiority in highly prioritized evaluation factors.