• Journal of the Korean Geosynthetics Society
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• v.12 no.4
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• pp.1-10
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• 2013

Recently, the closed landfills are usually converted into parks or playground by the check the stability of landfill because they settle unevenly making them unsuitable for structures. When the closed landfill reuse, environmental and structural stability is important. To increase the bearing capacity and reduce the probable settlement of a foundation on waste disposal ground, a layer of geosynthetics(Geocell) is placed on the waste disposal ground. In this paper, the analysis of long-term settlement parameter correlation was performed, also the evaluation of bearing capacity reinforcement effect was conducted by field test. The settlement measured in the field, and input the same ground index when an integer to identify each model were compared by calculating the settlement. In addition, by adjusting the parameters of each model to identify the most similar to the value of field measurement parameters were calculated. Based on the analysis results, when the using the Park's model C(intermediate) = 0.0678, the expected settlement is similar to the field measurement results. Also, the bearing capacity of geocell reinforced ground is 1.193~1.554 times higher than that of unreinforced ground.

• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.43-50
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• 2012

In this research, the value of consolidation index was investigated. The range of the investigated standard deviation was analyzed and the deviation based settlement was calculated. Also, the compression index, which is the effect of the uncertainty in the ground was analyzed using the flimsy ground construction method. The settlement behavior in each embankment compaction stage was analyzed by applying the precompression load method, drainage expediting method, and displacement method through numerical analysis. In addition to the above, the settlement behavior was studied by analyzing the Piled Raft method which is stable for long term settlement. As a result, the final settlement amount based on average analysis results was that the settlement based on each of the average interpretation value, mean value of the maximum and minimum value and average compression index was different. The result of the comparison shows the difference in variation coefficient by the difference in time. Amongst them, the Piled Raft method shows the most consistent variation coefficient regardless of time and it also was least affected by the compression index of uncertainty.

• Journal of the Korean Geotechnical Society
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• v.21 no.4
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• pp.83-98
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• 2005

In this paper, a conceptual approach of the stress path method was newly proposed for a rational estimation of settlements of saturated clay deposits. In the proposed approach, settlement-related characteristic deformation behaviors of a specific clay deposit, which can cover all probable stress changes expected in the field, are experimentally evaluated in advance. Then settlements of various structures constructed on the deposit are easily estimated with only the characteristic deformation behaviors and without any additional experimental effort. In Part I of this paper, in order to provide practicality to the new conceptual approach, we developed a detailed procedure which is capable of evaluating characteristic deformation behaviors of a saturated clay deposit with only a limited number of tests and easily predicting deformations under a given stress change using the characteristic deformation behaviors. The applicability of the developed procedure was clearly shown by presenting an actual application example.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.5
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• pp.469-484
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• 2012

This study aims to numerically investigate ground movement around a square steel pipe as well as a group of square steel pipes induced by its and their ground penetration for trenchless construction of a concrete box. From numerical results, ground movement induced by a square steel pipe is much more dominantly governed by vertical displacement rather than horizontal displacement. Ground settlement induced by pipe penetration is much larger as the overburden becomes lower. The settlement is also shown to be slightly dependent upon the sequence of pipe penetration. More careful construction management is highly in demand during the penetration of upper pipes since their induced settlement occupies approximately 75 percent of total ground settlement after the whole construction of steel pipes.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.65-72
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• 2018

Seismically induced settlement exceeding dam freeboard may lead to a dam failure. The prediction of settlement is important also because it is also reported to be strongly related to longitudinal crack width and depth, which are critical indices used for safe evaluation of dams. The empirical correlation derived from numerical simulations is most often used. In this study, two-dimensional dynamic nonlinear analyses are performed using representative CFRD and ECRD fill dams. A total of 20 recorded motions are used to account for the influence on ground motion intensity and magnitude. The calculated crest settlements are correlated to four ground motion parameters, which are peak ground acceleration (PGA), peak ground velocity (PGV), Aria Intensity ($I_A$), and magnitude. It is demonstrated that using ground motion parameters in addition to PGA can significantly increase the prediction accuracy.

• Geotechnical Engineering
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• v.13 no.2
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• pp.137-154
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• 1997

Piling engineers in limit state design should consider both capacity of a pile and settlements of pile for stability of a structure. This paper analyzes the prediction of the settlements of single piles and nine-group piles installed at an overconsolidated clay site by common prediction methods and cone penetrometer test data obtained closely at pile locations. The effects of Young's modulus, which varies spatially in soil profile, on estimating the set tlements of piles have been investigated briefly. The predicted settlements for single piles and nine-pile group by using simple linear elan tic methods, Vesic's method and Poulos's method, overestimated overalls the measured valroes, and the assumption of Youngs modulus, which are to be varied linearly through the soil layers. did not significantly affect the settlement predictions.

• Journal of the Korean Geotechnical Society
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• v.15 no.4
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• pp.175-184
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• 1999

Several major land reclamation projects such as the Inchon International Airport construction, Songdo New City construction, LNG Tank and LPG storage construction are underway along the coastal line of Inchon in Korea. This study was carried out to investigate the feasible use of waste lime in the land reclamation projects. Waste lime (hydrated lime) used in this study is produced as a by-product in the manufacturing process of $Na_2CO_3$ from local chemical factory in Inchon. This study presents the characteristics of bearing capacity and settlement on the ground formed by layers of waste lime and dredged soil. From the laboratory and in-situ plate load test, the ultimate bearing capacity by in-situ test was 1.25~1.37 times higher than that of the theoretical ultimate bearing capacity. Based on the settlement analysis by Magset- II, the total settlement of layered ground steadly increased up to the ratio of waste lime depth 0.2 and therefore rapidly increased with the increase of waste lime depth. The results of the present study indicate that the ratio of waste lime depth for reclamation work is about 0.2.

• Proceedings of the Korean Geotechical Society Conference
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• 1991.10a
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• pp.332-347
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• 1991

Accurate prediction of future settlement is essential for the settlement control of soft soil by pre-loading method. To predict future settlement in clayey soft soils, several methods like Asaoka method, Hyperbolic Method and Hoshino method are currently being used. These methods predict the future sett1ement by mathmatical treatment of the measured settlement data on the basis of consolidtion theory and empiricism. But the correlation coefficient between the measured and the predicted settlement was relatively low (0.8~0.9). Also, the prediction of future settlemet for the design load is very difficult. In this article, the measured field settlement data was treated as the the field consolidation test. Hence, condolidation coefficient(Cv) and compression index(Cc) was evaluated from the field settlement data. Cv and Cc values from field data was used to calculate the degree of consolidation and settlement at desired time. By this method, the correlation coefficent between the measured and the predicted settlement was significantly increased(0.97~0.99). Also the settlement by the design load after the improvement of soft soil could be predicted reasonably. This method is quite rational and sound but it requires thousands of calculation steps. Today, by the aid of low priced personal computers above mentioned technique could be used much acre economically and effectively than conventional methods. This article presented the mechanisms and capacities of this method and demonstrated the enhanced correlation coefficient when applied to actual field settlement data.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.111-122
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• 2005

The data on the pile load tests performed on 35 large drilled shafts are analyzed to investigate the load-settlement characteristics of large drilled shafts embedded in bed rocks. Generally, the settlement of large drilled shafts embedded in bed rocks is too small to determine the ultimated load with application of the regulation in design code for either the total settlement or the residual settlement. Therefore, to determine the yield load of large drilled shafts embedded in bed rocks, p(load)-logS (settlement) curve method, which has been proposed originally for the driven pile, was applied to the investigation on the data of the pile load tests. This technique shows that the yield load can be determined accurately and easily rather than other conventional techniques such as P-S, logp-logS, S-logt, and P-S curve methods. An empirical equation is proposed to represent the relationship between pile load and settlement before the yield loading condition. And the settlement of piles was related with the depth embedded in rock as well as rock properties. Based on the investigation on the data of pile load tests, the resonable regulations f3r both the total settlement and the residual settlement are proposed to determine the yield load of large drilled shafts embedded in bed rocks.

• Journal of the Korean Geotechnical Society
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• v.23 no.1
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• pp.39-49
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• 2007

In this study, quantitative sensitivity analysis on rockfill material influencing the dam crest settlement of CFRD (Concrete-Faced Rockfill Dam) subjected to earthquake loading was carried out. The purpose of this study is to indicate the most important input parameter from the results of sensitivity analysis, to show the quantitative variation of settlement at the crest of CFR type dam during earthquake with this input parameter, and to recommend the approximate estimation method of the settlement on the crest of CFRD subjected to earthquake loading. The statistic characteristics of rockfill parameters which were obtained from large triaxial tests were evaluated. The total 108 dynamic numerical analyses (2 input earthquake, 2 magnitudes for each earthquake, 27 rockfill material property combinations) on CFRD were conducted. The global sensitivity analysis was carried out using the results of numerical analysis. From the sensitivity analysis, It was found that the crest settlement of the CFRD subjected to earthquake was absolutely affected by the shear modulus of rockfill material irrespective of the input earthquakes and the magnitude of input acceleration. On the contrary, it was found that the effect of cohesion and friction angle of rockfill was negligible. From the results of sensitivity analysis and numerical analysis, the approximate estimation method of the settlement on the crest of CFRD subjected to earthquake loading was recommended on condition that the rockfill shear modulus and simple dam information was known.