• Journal of the Korean GEO-environmental Society
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• v.13 no.12
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• pp.35-42
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• 2012

There are many large-scale coastal region landfill and land development by loading to use territory efficiently, this regions are mostly soft clay ground. Constructing structures and road on the soft ground bring about engineering problems like ground shear fracture and a big amount of consolidation by bearing capacity. Improvement of soft soil is required to secure soil strength and settlement control. In improvement of soft soil, predict for the amount of settlement based on field surveyed reports are important element for estimating pre-loading banking height and the final point of consolidation. In this study, there is calculating theoretical settlement by analyzing field surveyed report and ground investigation to improvement of soft soil with pre-loading and vertical drain method. And present settlement prediction method reflect soil characteristics in Gimpo Hangang site by analysing prediction settlement and observational settlement during compaction using hyperbolic, ${\sqrt{s}}$, Asaoka method.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.888-895
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• 2009

Compaction is a process of increasing soil density using physical energy. It is intended to improve the strength and stiffness of soil. In embankment, degree of compaction affects the construction time, money, also method of soil improvement. In large scale embankment project, difficulties of embankment should change due to uncertainty of settlement. So it is very important to predict the final settlement and factor of safety induced by embankment. In many construction site, there are primarily design of high embankment using in-situ soil. Therefore numerical analyses are necessary for valid evaluation of the settlement prediction. But due to the construction cost and schedule, there were lacking in properties of soil and also limited number of in-situ test were performed. So we proposed the method that can easily estimate the proper soil parameters and suggest the proper method of numerical analysis. From this, two-dimensional finite-difference numerical analysis was conducted to investigate the settlement and factor of safety induced by embankment with various case of compaction rate and embankment height.

• Geotechnical Engineering
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• v.13 no.6
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• pp.107-122
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• 1997

This paper presents a ground surface settlement prediction method for shield tunneling in cohesive soils. In order to develop the method, a parametric study on shield tunneling was performed by using a threetimensional elasto-plastic finite element analysis, which can simulate the construction procedure. By using the results of the finite element analysis, the ground movement mechanism was investigated and a base which relates the ground surface settlement and iuluencing factors was formed. The data base was then used to formulate semi -empirical equations for both surface settlement ratio above tunnel face and imflection point by means of a regression analysis. Furthermore, a prediction method for transverse and longitudinal surface settlement profiles was suggested by using the leveloped equations in conjunction with the normal probability curve. Effectiveness of the developed method was illustrated by comparing settlement profiles obtained by using the developed method with the results of finite element analysis and measured data. Based on the comparison, it was concluded that the developed method can be effectively rosed for practical applications at least within the conditions investigated.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.27-33
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• 2003

This study analyzed an application possibility of neural network to overcome problems of conventional settlement prediction. It is very important to estimate settlement in preloading method used to improve soft ground. At present, Hyperbolic method, Hoshino method and Asaoka method are used mostly in the prediction of settlement. But these methods can not predict settlement at the phase of design. On the other hand, neural networks are capable of predicting settlement through accumulated data in the phase of design and this method can be easily applied in practice. In this study Elman neural network is used to estimate future settlement.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.168-171
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• 2001

It is a common practice to extract water from the ground for domestic, agricultural or industrial uses or to lower the groundwater level for construction work. An accurate prediction of ground settlement Is sometimes crucial when groundwater is pumped. This case study have shown that drawdown of the groundwater table may cause ground subsidence. Many settlement gauges was installed in the vicinity of a pumped well to measure the surface settlement. The relationships between the level of groundwater drop and surface settlement is investigated In this research.

• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.351-362
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• 2007

Predicted behaviour of a soft clay deposit in design stage is sometimes different from in-situ settlement and pore pressure measured during and after construction. In this paper, characteristics of settlement and pore pressure occurred in soft soil deposits were investigated briefly in order to get a better understanding of time-dependent viscoplastic behaviour and prevent geotechnical problems resulted from long-term settlement, differential settlement, etc.

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.19-26
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• 2012

In this study, characteristics of consolidation settlement of soft grounds adapting preloading method and vertical drain method were compared. A real measurement settlement is compared with predicted one by the future settlement prediction method like the Asaoka's method, the Hyperbolic method and the Hoshino method. A accuracy of predicted future settlement by the Asaoka's method is relatively higher than the Hyperbolic method or the Hoshino method generally. But in the area conducted with the vertical drain method, settlement prediction accuracy of three methods is similar unlike popular beliefs; Asaoka's is the better method for prediction than others. The study area is also confirmed by investigation of the drainage system after applying the change through the N values, soil physical and mechanical properties were investigated, and physical properties are improved.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.706-712
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• 2022

Purpose: In this study, field experimental research was conducted to analyze the settlement characteristics of soft ground in the central inland region of Korea and use it in practice. Method: The design predicted values and comparative analysis were performed using the ten settlement measurement data actually measured in the field experiment. For the design prediction value, Terzaghi's one-dimensional consolidation settlement analysis was used. In the experiment, the surface subsidence plate was used for field measurement. Result: The settlement behavior of the predicted value and the actual value was generally similar, but in the settlement value, the actual settlement value showed a settlement behavior of 30% or less compared to the predicted settlement value. The rate of consolidation settlement in this study area was in the range of 9.6% to 27.0%, and the average value was 18.21%. It is analyzed that the prediction of the settlement amount of the silty soils distributed in the inland plains of the central region of Korea can be relatively overestimated. Conclusion: It is judged that precise ground investigation and detailed prediction are necessary because there is a possibility of over-design in the design for predicting the amount of settlement of the silty soils distributed in the inland plains of the central region of Korea.

• Journal of the Korean GEO-environmental Society
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• v.15 no.11
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• pp.21-27
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• 2014

In this study, the prediction methods for the crest settlement after impounding and the maximum internal settlement during dam construction were proposed through the analysis on settlement data at 46 monitored points of 37 Center-Cored Rockfill Dams (CCRDs). Results from this analysis provided that the crest settlement increases with elapsed time, and from the relationship between the dam height and the maximum internal settlement during dam construction, it is confirmed that the internal settlement was largely evaluated when the coarse-grained material was used as the dam core. This internal settlement increased in proportion to the dam height. In addition, the crest settlement of the CCRD with the core compacted with fine-grained material was relatively large. It is expected that the results of this study would provide the practical tool for the design, construction and management of CCRDs.

• Geomechanics and Engineering
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• v.31 no.6
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• pp.637-651
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• 2022

The seismic design of embankment dams requires more comprehensive studies to understand the behaviour of dams. Deformations primarily control this behaviour occur during or after earthquake loading. Dam failures and incidents show that the impacts of deformations should be reviewed for existing and new embankment dams. Overtopping erosion failure can occur if crest deformations exceed the freeboard at the time of the deformations. Therefore, crest settlement is one of the most critical deformations. This study developed empirical formulas using Gene Expression Programming (GEP) based on 88 cases. In the analyses, dam height (H_d), alluvium thickness (H_a), the magnitude-acceleration-factor (MAF) values developed based on earthquake magnitude (Mw) and peak ground acceleration (PGA) within this study have been chosen as variables. Results show that GEP models developed in the paper are remarkably robust and accessible tools to predict earthquake-induced crest settlement of embankment dams and perform superior to the existing formulation. Also, dam engineering professionals can use them practically because the variables of prediction equations are easily accessible after the earthquake.