• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.896-905
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• 2006

Several soil parameters such as particle characteristics, geological element, drainage and loading conditions are influenced on the shear strength of soil. The characteristics of soil particles are important factor to the shear strength of soil. However, this component is not well considered in the determination of soil strength in Korea. The particle shape of sand was analyzed by utilizing SEM(Scanning Electron Micrograph) and compared its results in terms of aspect ratio, angularity and roughness. Based on the determined soil parameters, the ultimate bearing capacity of sandy ground was estimated by using Terzaghi bearing capacity equation.

• Journal of Industrial Technology
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• v.35
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• pp.81-88
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• 2015

The single regression method was used to analyze the correlationship between the compression index with mechanical properties for reclaimed marine clays in the Gyeonggi coast of Korea. As results of performing regression analysis for 62 samples about reclaimed marine clays in the Gyeonggi coast of Korea, linear regression lines between compression index and natural water content, void ratio in situ, and liquid limit respectively were obtained. The changed properties of reclaimed soil due to disturbance during dredging and reclaiming could be investigated by comparing with the existing empirical correlation equations for the original ground where dredging was performed.

• Journal of Industrial Technology
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• v.18
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• pp.77-86
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• 1998

This study is to provide the useful data for the design and construction of the geotechnical engineering works by collecting and analyzing the soil properties of granite soil in the Kangwon Province. Data base was obtained from 92 field sites in the Kangwon province divided into 15 areas based on administration district. Total numbers of data were 478. Correlations between soil constants, especially compaction properties, were obtained by performing statistical analysis. Analyzed results were as follows. 1. Most of granite soil consists of SM and GM based on United Soil Classification System. 2. Mean gravity of granite soil is 2.65 3. High correlations between optimum moisture content and the maximum dry density, plasticity index and liquid limit are obtained. 4. Analyzed results between other soil constants show relatively low correlation. However, they show consistent trends matchable to geotechnical engineering senses.

• Geotechnical Engineering
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• v.14 no.1
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• pp.81-92
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• 1998

Coal ash from thermal power plants has been produced in large quantity and discarded uselessly, However, it is possible to supply construction material properly by utilizing the coal ash as construction material. In this study, the applicable model and its applicability for deformation analysis of coal ash fill and reclamation ground are studied. Camflay model gives complete constitutive law which illustrates deformation and pore water pressure while soil is loaded under the various stresses at drained and undrained conditions. The merit of proposed model which is acquired from laboratory tests is that only a few soil parameters are available. The whole parameters of Camflay model are obtained by typical mechanical test and CV triaxial test on the sample with optimum mixing ratio( i.e. fly ash : bottom ash=5:5) Then the results from proposed numerical analysis are compared with laboratory results. The differences between laboratory test and numerical analysis are negligible. Parameters deter mined from laboratory tests are useful as a basic data for deformation analysis of coal ash reclamation ground using Camflay model.

• Journal of the Korean Geotechnical Society
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• v.24 no.5
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• pp.27-35
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• 2008

Geotechnical characteristic values for reliability-based design were analyzed using domestic marine clays. Analysis results indicate that there were close to mean values in oder of Student/Ovesen, Schneider and EN 1990's approach. However, it was found that the EN 1990's approach is inappropriate far estimating geotechnical characteristic value due to low reliability of estimation results. Four approaches had a trend of evaluating characteristic value conservatively with increasing of soil variability. Also, stability and settlement of breakwater subjected to nominal stress with unimproved soft grounds were computed to investigate the effects of estimated characteristic values. In case of using the Schneider's approach, the ratio of allowable bearing capacity/acting loads suggested 65% of that obtained from using the arithmetic mean approach, and showed underestimated value of 13.6% of the settlement obtained from the latter. The comparison of case designs using a representative value from arithmetic mean approach with the proposed approaches, using characteristic value showed that the former was mostly overestimated.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.11a
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• pp.136-139
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• 2001

제주도는 당근 재배면적이 2000여 ha로 전국의 50%, 생산량은 60% 차지하는 주요 월동작물이다. 재배지역은 화산회토 지역인 성산읍지역과 패사토지역인 구좌읍지역으로 크게 나눌 수 있다. 화산회토의 토양은 배수가 잘되고 토질이 부드럽고 작토층이 깊어 당근재배에 (Dowker and Jackson, 1977, Rubatzky and Quiors, 1999) 유리한데, 아직까지 이 지역에 적합한 품종이 밝혀지지 않은 실정이다. (중략)

• Geotechnical Engineering
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• v.11 no.3
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• pp.43-54
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• 1995

The aim of the work described in this paper is to develope a constitutive model for the prediction of an unsaturated soil and to confirm the application'of the model, which is composed of the elastic and plastic part in consideration of the matric suction and the net mean stress. From test results, volume changes and deviator stresses are analyzed at each state and their relationships are formulated. The application of the model to silty sands is confirmed by the comparison between test and predicted results. During drying -wetting and loading -unloading processes for isotropic states, the agreement between predicted and test results are satisfactory. Predicted deviator stresses are well agreed with test results in shearing process. Overall acceptable predictions are reproduced in high confining pressure. Usefulness of the model is confirmed for the unsaturated soil except volumetric strain, which is not well agreed with the test results due to deficiency of dilatancy of the model in low confining pressure. It is, therefore. recommended to study the behavior of dilatancy for an unsaturated soil.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5957-5962
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• 2011

In this study, the values of the four kinds of cone factors($N_{kt}$, $N_{ke}$, $N_{{\Delta}u}$, and recently proposed $N_e$) and the soil properties, for the northeastern part of Shiwha area, were investigated. The measured and calculated undrained strengths, which have been obtained from the various experimental data, were compared with each other, and their relationship with the plastic index was also studied. The strength from the $N_{{\Delta}u}$ method was unexpectedly not reasonable and the higher values of cone factors were observed with the larger plastic index.

• Geotechnical Engineering
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• v.3 no.1
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• pp.25-38
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• 1987

The prediction of driving stresses in piles is necessary for optimum selection of driving hammers, better design of precast piles, enact assessment of drivabilities and complete description of piling specifications. However, the existing pile-driving formulas based on the theory of Newtonian impact have some defects and shortcomings; the numerical method by the wave equation analysis using electronic computer usually Involves various uncertainties and limitations which can yield erroneous outcomes because it employs soil constants of which the nature is unknown as essential parameters and ignores the effect of residual stresses set up in the pile .after each hammer blow; and the electronic measuring technique needs extra time and expense. The method developed herein is presented for the purpose of giving field engineers a reliable and convenient analytical procedure for the prediction of driving stresses along the full length of pile using the most effetive parameters without resort to electronic computer. This method is based on the fundamental mechanics of stress waves in elastic rods and takes into account the effect of residual stresses induced by reversed friction in piles.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.371-378
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• 2003

The compression index of clay distributed in the west and south coast of the Korean Peninsula had been studied. Compression index was obtained from the conventional consolidation test, and was conducted accordingly to obtain the field virgin compression curve by means of Schmertmann's graphical correction. To examine a correlation closely between physical properties of soils($e_o$, LL, w) and compression index(Cc), linen. and non-linear regression analysis were employed based on the data collected from tests. The conclusions are as follows. The compression index obtained by means of Schmereann's graphical correction is about 1.16 times for the value of original oedometer test curve for U/D samples. Non-liner regression curve was preferable to establish a correlation equation rather than linear regression curve. All derived equations so far achieved have been summarized and given. However, linear equation is better for practical use so that part by part simplified linear equations were also suggested alternatively together with their own non-linear regression curve.