• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.526-528
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• 2003

There are some reports which are about measuring the discontinuity from 3D model of rock surface. To generate 3D model is mainly based on remote sensing technique like laser scanning and digital stereo photogrammetry. It is obtained the DEM of the rock slope using above techniques in this study, and examined a suitability and improvement of the photogrammetry for the rock slope by overlap the DEM. It seems that accuracy of DEM generated by photogrammetry technique is influenced by the geometry of rock and type of joint.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1778-1782
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• 2007

Based on three-dimensional (3-D) FE limit analyses, this paper estimates effect of internal pressure on plastic limit loads for elbows with circumferential through-wall crack under in-plane bending incorporating large geometry change effects. Circumferential through-wall crack in extrados is considered. The FE limit analyses using the large geometry change option provide plastic collapse loads (using the twice-elastic-slope method). For the bending mode, closing bending is considered. Other relevant variables affecting plastic limit loads are systematically varied, related to pipe bend geometry (the mean radius, thickness and bend curvature) and defect geometry (the length of circumferential through-wall crack).

• International Journal of Highway Engineering
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• v.15 no.4
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• pp.95-105
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• 2013

PURPOSES: The purpose of this study is to research the influence of road traffic noise by road slope through the analysis of the field road traffic noise and determine consideration of road slope in the case of appling active noise cancellation. METHODS: This study measures vehicle's noise by the NCPX method at the three field sections such as uphill, downhill, and flatland. Total sound pressure and sound pressure level by the 1/3 octave band frequency are calculated through the raw field data. Total sound pressure level is compared by ANOVA test and T test statistically. The results obtained are compared in accordance with the road slope and the progress of the uphill section. RESULTS : The noise characteristic of early, medium, and last parts of uphill was found to be consistent when the vehicle was travelling uphill section. The result of statistical test, it was shown that total sound pressures are not different each other. According to the comparison by the geometry, sound pressure of the uphill section was higher than those of the flatland and downhill section in high frequency band. By the result of statistical test, total sound pressure are different according to geometry in the case of high vehicle speed. In the comparison result by road slope, each sound pressure level was found to be consistent in total frequency. However, total sound pressure proportionally increased according to road slope. CONCLUSIONS: It is found that the effect of road slope on noise generation was little in this experimental sites.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.05a
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• pp.3-34
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• 1998

The stability condition of rock slopes is greatly affected by the geometry and strength parameters of discontinuities in the rock masses. Rock slopes Involving movement of rock blocks on discontinuities are failed by one or combination of the three basic failure modes-plane, wedge, and toppling. In rock mechanics, practically all the parameters such as the joint set characteristics, the rock strength properties, and the loading conditions are always subject to a degree of uncertainty. Therefore, a reasonable assessment of the rock slope stability has to include the excavation of the multi-failure modes, the consideration of uncertainties of discontinuity characteristics, and the decision on stabilization measures with favorable cost conditions. This study was performed to provide a new numerical model of the deterministic analysis, reliability analysis, and reliability-based optimization for rock slope stability. The sensitivity analysis was carried out to verify proposed method and developed program; the parameters needed for sensitivity analysis are design variables, the variability of discontinuity properties (orientation and strength of discontinuities), the loading conditions, and rock slope geometry properties. The design variables to be optimized by the reliability-based optimization include the cutting angle, the support pressure, and the slope direction. The variability in orientations and friction angle of discontinuities, which can not be considered in the deterministic analysis, has a greatly influenced on the rock slope stability. The stability of rock slopes considering three basic failure modes is more influenced by the selection of slope direction than any other design variables. When either plane or wedge failure is dominant, the support system is more useful than the excavation as a stabilization method. However, the excavation method is more suitable when toppling failure is dominant. The case study shows that the developed reliability-based optimization model can reasonably assess the stability of rock slopes and reduce the construction cost.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.1008-1015
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• 2006

Based on three-dimensional (3-D) FE limit analyses, this paper provides plastic limit, collapse and instability load solutions for pipe bends under combined pressure and in-plane bending. The plastic limit loads are determined from FE limit analyses based on elastic-perfectly plastic materials using the small geometry change option, and the FE limit analyses using the large geometry change option provide plastic collapse loads (using the twice-elastic-slope method) and instability loads. For the bending mode, both closing bending and opening bending are considered, and a wide range of parameters related to the bend geometry is considered. Based on the FE results, closed-form approximations of plastic limit and collapse load solutions for pipe bends under combined pressure and bending are proposed.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.339-346
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• 1999

The stability of rock slope is considered to have a deep relation with types of rocks because types of rocks have their own typical weathering profiles, geological structures and characteristics of failures. Therefore it is essential for the evaluation of rock slope stability to analyze geological and engineering characteristics in rock mass. The data which collected from investigated slopes in sedimentary rock of Kyengsang Basin along highways were analyzed. Primary factors affecting slope stability in rock mass are: dips and strikes of slopes and discontinuities, shear strength of discontinuities, slope geometry and geological structures etc.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.10a
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• pp.69-72
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• 1993

In this paper, relatively new slope reinforcing system using an anchored wall is presented. For practical design purposes a method of external and internal stability analyses of an anchored wall installed at the toe of the original unstable or quasi-stable slope is developed. And also Murray's full-scale test results are compared with the passive resistance of an anchor predicted by the present study. Finally a design example of reinforced slope using an anchored wall is analyzed, and the safety as well as benefits is compared with a method of changing the geometry of the original unstable slope.

• ETRI Journal
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• v.42 no.3
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• pp.420-432
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• 2020

The reconstruction of archaeological fragments in 3D geometry is an important problem in pattern recognition and computer vision. Therefore, we implement an algorithm with the help of a 3D model to perform reconstruction from the real datasets using the slope features. This approach avoids the problem of gaps created through the loss of parts of the artifacts. Therefore, the aim of this study is to assemble the object without previous knowledge about the form of the original object. We utilize the edges of the fragments as an important feature in reconstructing the objects and apply multiple procedures to extract the 3D edge points. In order to assign the positions of the unknown parts that are supposed to match, the contour must be divided into four parts. Furthermore, to classify the fragments under reconstruction, we apply a backpropagation neural network. We test the algorithm on several models of ceramic fragments. It achieves highly accurate results in reconstructing the objects into their original forms, in spite of absent pieces.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.6
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• pp.114-120
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• 1997

To assess the validity of the previously computed finite element analysis results, the photoelastic experiment was carried out to determine stress intensity factors for crack originating from thin section of integrally stiffened plates having discontinuous thickness interface. The stress intensity factors were deter- mined by using linear slope method of photoelastic data. Results are presented as variable thickness geometry factor. $F_{IV}$ , for various crack lengths and thickness ratios. The experimental values of F/ sub IV/are compared with 3-D finite element analysis results. The correlation between experimental values and analysis results is resonably good.

• Geomechanics and Engineering
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• v.10 no.3
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• pp.257-267
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• 2016

Charts are used extensively in slope practical application to meet the need of quick assessment of rock slope design. However, Charts for estimating the shear strength of the rock mass of a slope are considerably limited. In this paper, based on the Hoek-Brown (HB) criterion which is widely used in rock slope engineering, we present charts which can be used to estimate the Mohr-Coulomb (MC) parameters angle of friction ${\phi}$ and cohesion c for given slopes. In order to present the proposed charts, we firstly present the derivation of the theoretical relationships between the MC parameters and ${\sigma}_{ci}/({\gamma}H)$ which is termed the strength ratio (SR). It is found that the values of $c/{\sigma}_{ci}$ and ${\phi}$ of a slope depend only on the magnitude of SR, regardless of the magnitude of the individual parameters ${\sigma}_{ci}$(uniaxial compressive strength), ${\gamma}$(unit weight) and H (slope height). Based on the relationships between the MC parameters and SR, charts are plotted to show the relations between the MC parameters and HB parameters. Using the proposed charts can make a rapid estimation of shear strength of rock masses directly from the HB parameters, slope geometry and rock mass properties for a given slope.