• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2006.03a
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• pp.277-287
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• 2006

• Proceedings of the Korean Geotechical Society Conference
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• 1993.06b
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• pp.167-189
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• 1993

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11b
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• pp.41-58
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• 2000

• Proceedings of the Petrological Society of Korea Conference
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• 2004.05a
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• pp.74-74
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• 2004

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.33-41
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• 2003

The large planar failure has occurred in a rock cut slope of highway construction site in Boeun. This area is considered to be unstable since the discontinuity, whose orientation is similar to the orientation of the failure plane, is observed in many areas. Therefore, several analysis techniques such as SMR, stereographic analysis, limit equilibrium, numerical analysis, which are commonly used in rock slope stability analysis, are adopted in this area. In order to analyze the stress redistribution and nonlinear displacement caused by cut, which are not able to be obtained in limit equilibrium method, DEM and shear strength reduction technique were used in this study. Then the factors of safety evaluated by shear strength reduction technique and limit equilibrium were compared. In addition, the factor of safety under fully saturated slope condition was calculated and subsequently, the effect of the reinforcement was evaluated.

• Korean Journal of Agricultural Science
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• v.23 no.1
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• pp.1-12
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• 1996

To design the safe and rational rock slope, several rock slopes of roads in Kang-won area were analyzed, and the following results were obtained ; 1. The results were analyzed by stereographic projection at the rock slope that the joint was developed. All of the sloped which were designed by standard slope of rock was not considered that the joints were unstable. 2. The relation of rainfall and slope failure, as well as the danger of failure, was very high when the maximum hourly rainfall was larger than 20mm and when there was a 2-day cumulative rainfall that was larger than 200mm. 3. In the design of rock slope, operated by the stereographic projection considering discontinuity. If turn out unstable, it should be analyzed carefully using the limit equilibrium method. 4. In the design of rock slope, it is desirable to consider the discontinuity of rock(joint, bedding, fault).

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.83-92
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• 2005

The aim of this study was to investigate damage conditions of cut slope structures due to acid rock drainage (ARB) and to assess the acid production potential of various rocks. Acid rock drainage is produced by the oxidation of sulfide minerals contained in coal mine zone and mineralization belt of Pyeongan supergroup and Ogcheon group, pyrite-bearing andesite, and Tertiary acid sulfate soils in Korea. Most of cut slopes producing ARB have been treated with shotcrete to reduce ARD. According to the field observations, ARD had an adverse effect on slope structures. The corrosion of shotcrete, anchors and rock bolts and the bad germination and growth diseases of covering plants due to ARD were observed in the field. The concentration of heavy metals and pH of ARD from cut slope exceeded the environmental standard, indicating a high potential of environmental pollution of surrounding soil, surface water and ground water by the ARD. According to acid base accounting (ABA) of the studied samples, hydrothermally altered volcanic rocks, tuffs, coaly shales, tailings of metallic mine had a relatively high potential of acid production but gneiss and granite had no or less acid production potential. It is expected that the number of cut slopes will increase hereafter considering the present construction trend. In order to reduce the adverse effect of ARD in construction sites, we need to secure the data base for potential ARD producing area and to develop the ARD reduction technologies suitable.

• Economic and Environmental Geology
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• v.38 no.3 s.172
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• pp.305-317
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• 2005

This study addresses the preliminary results of rock slope stability analyses including hazard assessments for slope failure conducted on the selected sections of rural road cut slope which are about 4 km long. The study area is located in the Mt. Chuntae northeast of Busan and mainly composed of Cretaceous rhyolitic ash-flow tuff', fallout tuff, rhyolitc and andesite. The volcanic rock mass in the area has a number of discontinuities that produce a potentially unstable slope, as the present cut slope is more than 70 degrees in most of the slope sections. Discontinuity geometry data were collected at selected 8 scanline sections and analyzed to estimate important discontinuity geometry parameters to perform rock slope kinematic and block theory analyses. Kinematic analysis for plane sliding has resulted in maximum safe slope angles greater than $65^{\circ}$ for most of the discontinuities. For most of the wedges, maximum safe cut slope angles greater than $45^{\circ}$ were obtained. Maximum safe slope angles greater than 80" were obtained fur most of the discontinuities in the toppling case. The block theory analysis resulted in the identification of potential key blocks (type II) in the SL4, SL5, SL6 and SL8 sections. The chance of sliding taking place through a type ll block under a combined gravitational and external loading is quite high in the investigated area. The results support in-field observations of a potentially unstable slope that could become hazardous under external forces. The results obtained through limit equilibrium slope stability analyses show how a stable slope can become an unstable slope as the water pressure acting on joints increases and how a stable slope under Barton's shear strength criterion can fail as the worst case scenario of using Mohr-Coulomb criterion.

• Tunnel and Underground Space
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• v.16 no.6 s.65
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• pp.506-525
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• 2006

For the design of large scale rock slope which has complex formations and geological structures, generally, insufficiency of geotechnical investigations and laboratory tests are the main factors of slope failures doling construction. In such case, remedial measures to stabilize slope should be selected and applied through reliable investigations and analysis considering the geotechnical characteristics. The rock slope of this study, one of the largest cut slopes in Korea with a length of 520.0 m and maximum height of 122.0 m consists of metasedimentary rocks. And a case study on the causes of large-scale rock slope failure was carried out by analysis of landslides history and site investigations during construction. When the slope with the original design slope of 0.7: 1.0 (H:V) was partially constructed, the slope failure was occurred due to the factors such as poor conditions of rocks (weathered zone, coaly shale and fault shear zone), various discontinuities (joints, foliations and faults), severe rain storm and so on. The types of failures were rockfall, circular failure, wedge failure and the combination of these types. So, the design of slope was changed three times to ensure long-term slope stability. This paper is intended to be a useful reference for analyzing and estimating the stability of rock slopes whose site conditions are similar to those of this study site such as geological structures and geotechnical properties.

• Proceedings of the Korean Geotechical Society Conference
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• 1995.06a
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• pp.59-95
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• 1995