• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.569-572
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• 2008

The slope failures frequently occurred during heavy rainfalls in Korea of which 70% consists of mountains result in average 60 casualties and hundreds of millions US dollars of property damage. The status of design methods were analyzed with use of existing 102 design reports, Also, the design standards related to cut slopes are suggested by various institutions but the contents of standards are not proper to reflect the complicated geological features of Korea. And most reports rarely followed the suggested standards and are insufficiently conducted.

• The Journal of Engineering Geology
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• v.16 no.2 s.48
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• pp.189-199
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• 2006

This paper presents a field study of the stability of slope collapsed during road construction and proposes a reasonable countermeasure if the current slope is unstable. As a result of slope investigation, it was found that the slope includes five tension cracks and the sliding surface is started from the tension crack and propagated the surface soil layer through weathered rock layer. The slope stability analyses are conducted in case of dry and rainfall seasons. The results indicate that the slope is unstable status. A reinforcement method of slope failure should be selected according to the scale of failure. That is, the scale of slope failure, which is classified small, middle and large size determines the reinforcement method of slope. Since the slope interested in this study is large size failure slope, the reinforcement method to control slope failure is selected stabilizing piles, and seed spray and drainage of surface waterare also selected to remain the factor of safety. The SLOPILE (Ver. 3.0) program is applied in order to do stability analysis of slope reinforced by piles. As the result of analysis, the slope reinforced by a row of piles shows the stable state. It is clearly confirmed that the stabilizing of piles can improve the stability of slope.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.4
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• pp.45-59
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• 2016

This study introduced wood waste into revegetation base materials for recovery of highway cut slope. The object of this study is to derive the mixing ratio of wood waste, kaoline and silica by conducting a test installation, monitoring, analysis and evaluation. The following items were investigated and analyzed each experimental zone to deduce the mixing ratio of wood waste, kaoline and silica on slope revegetation base materials: the physical and chemical properties of the vegetation base materials, soil-hardness, soil-humidity, collapse and eroded spots, established number of trees, existing species of grass and tree species, vegetation coverage ratio, pest status, and invasion of disturbance species. The revegetation method was evaluated in each experiment zone which had different mixing ratios. As a result, experiment zone C scored 47 points out of 60 as the best revegetation method. However, this result has been derived from just one construction and short-term monitoring. In order to derive the suitable and dependable mixing ratio, conducting an objective revegetation method evaluation and long-term experimenting and monitoring is required.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.6
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• pp.187-200
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• 2020

Despite the eco-friendly route plan, road slopes were collapsed due to road construction, resulting in human and property damage. To solve this problem, the Ministry of Land, Transport and Maritime Affairs established guidelines in 2009 to conduct a test-bed for slope recording considering the conditions of the site and the ecological environment, and divided them into recording quality and economic evaluation. The following results were obtained by analyzing 183 construction methods of cut-soil sections at 60 sites from 2012 to 2018 for road slope afforestation research. Straw net+seedspray, vegetation media spray method 1T, 3T were used the most, and vegetation media spray method 3T(patent) was excellent in quality, and straw net+seedspray was excellent in economics. As a result of analyzing the market unit price and the construction unit price, vegetation media spray method submitted the construction unit price at up to 60% lower than the market unit price. As a result of the analysis of the key factors of the greening method evaluation, the economic assessment had the greatest influence on all evaluation items. Problems in the evaluation method of revegetation were first identified as problems in the allocation of points and secondly as problems in the evaluation criteria. As for the improvement of the economic assessment criteria, the method was proposed to evaluate the same method based on market unit price when the same method was constructed, and not to conduct an economic assessment if there was a difference in market unit price between methods, or to add weight to the scores. Based on the monitoring data of 60 road slopes, this study drew up problems and improvement measures. However, with regard to scoring, research on appropriate scoring is needed by examining the current status.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.6
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• pp.215-226
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• 2015

This study introduced food waste into re-vegetation base materials for surface loss recovery of carry-away highway cut slope. The object of this study is to derive the mixing ratio of food waste by conducting a test installation, monitoring, analysis and evaluation for recovery of carry-away highway cut slope. The following items were investigated and analyzed each experimental zone to draw mixing ratio of re-vegetation base materials and food waste : the physical and chemical properties of the vegetation base materials, soil-hardness, soil-humidity, left out and the collapsed point, established number of trees, species richness of grass species and tree species, coverage, pest status, and invasion of disturbance species. The re-vegetation method was evaluated by each experiment zone which has different mixing ratio. As a result, experiment zone A was rated 45 points out of 60 rating points as the best re-vegetation method. However, this study result has been derived from one construction and short-term monitoring. In order to derive the suitable and dependable mixing ratio, conducting an objective re-vegetation method evaluation and long-term experiment and monitoring is required.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.2
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• pp.1-15
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• 2007

A variety of revegetation methods are being utilized and developed. However, most of revegetation methods used on highway slopes in Korea are based on foreign-introduced plant varieties to stabilize road surfaces and to administer afforestation for surface covering at an earlier phase. Therefore. it results in various problems. such as failure to achieve harmony with the surrounding vegetation and 10 cause re-denudation of slopes as the foreign-in introduced plant varieties wane out from 2~3 years after hydro-seeding, etc. In addition, some of the revegetation plants seeded in the earlier phase grow excessively high, thus causes successional problems, such as to inhibit the invasion of the secondary vegetation from the surrounding areas, etc. Therefore, in this study, 160 slopes located in the nationwide express highways have been investigated and analyzed in order to produce basic data for restoration of ecological environment in slopes created on a long-term basis by investigating and analyzing locational characteristics of cut and filled slopes in express highways, status of revegetation methods, characteristics of soil and plant-ecological environment. 1. Investigation on cut and embanked slopes in express highways was carried out in the total of 160 locations, which include 108 cut slopes and 52 embanked slopes. As a whole, the most frequently used revegetation method was seed spray, which was found to be used in the total of 55 target slops investigated. 2. Planting method of Wistaria floribunda applied to some of the blasted rock zones was found to cause damages as Wistaria floribunda trailed up the surrounding vegetation and the secondary invaded trees. In order to prevent this, this method must be used only in the lowest parts of large-sized slopes. Also, it will be required to administer continuous management and maintenance in the areas already planted with this plants. 3. The areas of blasted rock and ripping rock slopes were applied with coir net (net + seeding) method. However, many of these areas failed in achieving ground covering. Most areas where revegetation was in progress, they were covered with Eragrostis curvula(Weeping lovegrass) only. In areas with soil, such as decomposition of granite, where afforestation is difficult. In this slopes, soil base must be improved by hrdroseeding with thin-layer vegetation base application methods in order to achieve success in afforestation with native plants. 4. Woody species, rather than herb species, are more helpful in stabilization of slope surfaces. Therefore, it is important to be able to grow and protect woody species on highway slopes. Growth of woody vegetation is most largely influenced by soil depth. Thus, when hydro-seeding woody plants, it is recommended to apply at the upper layer of the slopes, which is capable to sufficiently provide the fundamentals required in plant growth.

• Tunnel and Underground Space
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• v.17 no.5
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• pp.350-359
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• 2007

Most large cut slopes of open pit mines, roadways, and railways are steeply inclined and composed with rocks that do not contain soils. However, these rock slopes suffer both weathering and fragmentation. In the case of steep slopes, falling rock and collapse of a slope may often occur due to surface erosion. Cast-in place concrete and rubble work are the most widely used earth structure-based pressure supports that act as restraints against the collapse of the rock slope. In order to overcome the shortcomings of conventional retaining walls, a segmental grid retaining wall is being used with connects precasted segments to construct the wall. In this study, laboratory model test was conducted to estimate deformation behavior of segmental grid retaining wall with configuration of rear strecher, height and inclination of the wall. In order to examine the behavior characteristics of a segmental grid retaining wall, this research analyzes the aspects of spacial displacement through relative displacement according to change in the inclination of the wall. Also, the walls behavior according to the formation and status of the rear stretcher which serves the role of transferring the load from the header and the stretcher which make up the wall, the displacement of backfill materials in the wall, and the location of the maximum load were surveyed and the characteristics of displacement in the segmental grid retaining wall were observed. The test results of the segmental grid retaining wall showed that there was a sudden increase in failure load according to the decrease in the wall's height and the size of the in was greatly decreased. Furthermore, it revealed that with identical inclination and height, the structure of the rear stitcher did not greatly affect the starting point or size of maximum horizontal displacement, but rather had a stronger effect on the inclination of the wall.