• Geotechnical Engineering
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• v.11 no.3
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• pp.17-26
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• 1995

Embracing a suggestion by Sullivan(1984) and minimizing the sum of the estimation variances at all thresholds, a rigorous solution to order relatioll problems in multiple indi gator kriging is formulated. By utilizing the particular structure of the resulting optimization problem, a solution algorithm is developed that requires little computational effort beyond the initial indicator kriging. Thus, this proposed solution is computationally efficient, mathematically consistent, and based upon an explicit statistical foundation-unlike many of the ad hoc solutions currently in use.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.541-548
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• 2008

Active application of auger-drilled piling is expected in Korea considering its advantage in noise and vibration problems against driven piling and its cost-effectiveness in comparison to the cast in-situ piling. The current design practice being used in Korea is adopted from the Japanese one, however the equipment and construction procedure is modified for the geotechnical conditions and construction circumstances in Korea. Therefore there is an urgent need for the establishment of the rational design criteria for the auger-drilled piling in Korea. As the preliminary work for the establishment, this paper presents the current practice in Korean railway constructions. Design criteria of Korea Railway Network Authority are introduced and its characteristics and the problems are described. Application cases of auger-drilled pile to railway construction are introduced as well.

• International Journal of Railway
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• v.2 no.4
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• pp.180-186
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• 2009

High speed railway challenge the design, construction and maintaining of traditional railway, many traditional design concepts have been changed. Transition of railway and bridge has two main problems. one is that different lines have different ability of resisting distortion in area of trial load, which was known that problem of smooth transition of stiffness, the other is that differential settlement between artificial structure and earth structure cause bending of railway. The two problems have effect on train moving. The principle of processing transition of railway and bridge is same in world, but it is difficult to find relationship between design standard of transition, vehicle performance, line standard, design speed and so on form documentation and data reports. Based on mechanics, the paper analyzed dynamic performance of transition of high speed railway, studied various rough elements which is effective to train moving, built mathematical model of interaction of train and transition of high speed railway and developed numerical simulation software. In various different work conditions, we did great quantity of numerical simulation, comprehensive analysis and performance analysis.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03c
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• pp.78-87
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• 2000

Enormous instruments have been installed to measure movement and stresses during and after the construction of Seoul Subway. However, a number of problems have been noticed and reported, such as planning, calibration, installation, contract procedure etc. Some of them are presented and discussed in this paper in order to call an attention to these problems and provide a baseline for the future improvement.

• Journal of the Korean Geotechnical Society
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• v.21 no.9
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• pp.25-34
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• 2005

This paper proposes a selection methodology composed of neural network (NN) and genetic algorithm (GA) to design optimal NN structure. We combine the characteristics of GA and NN to reduce the computational complexity of artificial intelligence applications and increase the precision of NN' prediction in the design of NN structure. Genetic selection approach of design parameters of NN is introduced to obtain optimal NN structure. Analyzed results for geotechnical problems are given to evaluate the performance of the proposed hybrid methodology.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1446-1451
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• 2008

The clay found in the river or in any waste water treatment plant usually have a very high content of water. A large amount of sediments hinder the navigation in river. In waste water treatment plant, there is requirement of settling the thick sludge. These problems are overcome by using rapid means of sedimentation and settling. This paper focus on how method of Electrokinetic sedimentation can be made faster. Sedimentation using Electrokinetic phenomenon has been discussed with varied voltage applied and effect and dose of coagulant in increasing the process. The experimental test has been carried out at water content that are generally present in the case of river and small canals carrying waste water. This paper also focus on different heavy metals concentration during the process and the power aspects of process. A series of experiment were done to support the proposed theory and how a bubble formation could hinder the purpose of experiment.

• Proceedings of the Korean Geotechical Society Conference
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• 1996.10a
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• pp.123-134
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• 1996

• Proceedings of the Korean Geotechical Society Conference
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• 1997.09a
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• pp.73-94
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• 1997

• Journal of the Korean Geotechnical Society
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• v.23 no.8
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• pp.117-127
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• 2007

Slope stability analysis is a geotechnical engineering problem characterized by many sources of uncertainty. Some of them are connected to the uncertainties of soil properties involved in the analysis. In this paper, a numerical procedure for integrating commercial finite difference method into probabilistic analysis of slope stability is presented. Since the limit-state function cannot be expressed in an explicit form, the ANN-based response surface method is adopted to approximate the limit-state function and the first-, second-order reliability method and the Monte Carlo simulation technique are used to calculate the probability of failure. Probabilistic stability assessments for a hypothetical two-layer slope and the Sugar Creek embankment were performed to verify the application potential to the slope stability problems. The examples show the successful implementation and the possibility of the extension of the proposed procedure to the variety of geotechnical engineering problems.

• Journal of the Korean Geotechnical Society
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• v.23 no.2
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• pp.19-27
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• 2007

Dry and wet test methods established by Korean industrial standards to estimate opening size of 3 types of geotextile which are widely used for filter of plastic drain board in Korea are performed to evaluate characteristics of the test methods and to compare the test results. Judging from test results, dry method is a relatively poor test, having lots of problems causing many errors but a simple-quick test. Wet method is a very specific test avoiding many of the problems of dry method such as electrostatic charges, trapping in the geotextiles and so on. However, one of wet test methods, KS K ISO 12956, takes long time to complete a test and is too strict to handle loss of granular material. Generally, opening size of a geotextile by wet test method is smaller than that of dry test method. Especially, opening size by KS F 2126 which is called hydrodynamic method but at present is not used anymore is similar to or smaller than that by KS K ISO 12956 method.