• Journal of the Korean Geotechnical Society
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• v.18 no.2
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• pp.107-121
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• 2002

In this study, GIS(Geographic Information System), a new approaching method, is proposed to effectively manage long-term settlements in the big reclamation sites. To verify an applicability of the proposed method, the prediction of long-term settlements which may occur in the overall soft deposits of the Incheon International Airport is carried out. During the process of the prediction of long-term settlements, measured settlement data obtained from an early stage of preloading are analyzed in detail. For purposes of the analysis, an estimation of the recompression index is also made based on the Nagaraj's research results. The coefficient of the secondary consolidation is further determined based on the relationship presented by the Mesri & Godlewski, which defines a ratio between the coefficient of the secondary consolidation and the recompression index.

• Journal of the Korean Geotechnical Society
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• v.16 no.2
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• pp.41-50
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• 2000

본 연구에서는 여러 침하모델들을 매립경과기간이 다른 아홉 개 지역의 실제 스레기 매립지 침하자료들에 적용하였다. 침하모델들을 적용한 결과, 매립연한이 증가할수록 향후 발생가능한 장기침하량도 상당히 감소하는 경향을 보였다. 신선한 쓰레기 매립지에서는 침하모델들마다 예측정도에서 큰 차이를 보이지만, 매립연한이 오래된 매립지들에서는 Power creep law를 제외하고는 예측정도에 있어서 큰 차이를 보이지 않음을 알 수 있었다.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.486-493
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• 2008

Consolidation settlements on marine dredged clays are often greatly and potentially damaging to structures. Currently, large-scale projects are in planning or progressing in Korea. These projects has been performed on thick and soft clay layers. So, the evaluation of long-term consolidation settlement is very important in design and construction. Therefore, In this study, a long-term consolidation characteristics of marine dredged clays are investigated. First, the relationship of $C_{\alpha}/C_c$ on marine dredged clays near Gwang-yang Port was evaluated. Second, long-term consolidation characteristics of the pseudo-preconsolidated ground were evaluated.

• Journal of the Korean Geosynthetics Society
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• v.18 no.3
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• pp.55-67
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• 2019

Deep soft ground in mouth of Nackdong river requires to be analysed with prediction method concerning characteristics of secondary consolidation from the beginning because it causes excessive settlement due to time-dependant secondary consolidation characteristics. This study investigated characteristics of extended settlement by conducting one-dimensional theory, elasto-plastic model and visco-elasto-plastic model as well as analyzing long-term measuring data observed over 2,000 days. According to one-dimensional theory and elasto-plastic model, there is not definite correlation between height of embankment and depth of soft ground while visco-elasto-plastic model showed similar result of settlement to that of long-term measuring data. Consequently it is suggested that applying visco-elasto-plastic model to developing deep underground place as studied area on predicting extended settlement before construction prevents economic loss and delay during process by preparing secondary consolidation characteristics.

• Journal of the Korean GEO-environmental Society
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• v.6 no.1
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• pp.5-13
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• 2005

The conventional settlement prediction method is not appropriate to model landfill settlement because it is very complex phenomenon. Biodegradation needs to be considered for long-term settlement since landfills are comprised of various organic materials and soils. As organic materials are decomposed, they directly influences on settlement producing LFG(Landfill Gas). Therefore, mathematical settlement prediction model is proposed based on the generated gas volume. As one of stabilization methods, leachate recycling system is adopted to model tests. Two model tests; one is leachate recycled, the other is non-recycled, are componented with proposed model and analysed regarding gas generation and settlement. The proposed mathematical model requires correction coefficients of 1.4 and 1.7 for non-recycled model and recycled, respectively. The recycled model showed 22% increase of long-term settlement more than the non-recycled model.

• Journal of the Korean Geotechnical Society
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• v.24 no.7
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• pp.37-42
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• 2008

This paper estimates the long-term settlement of Incheon unsanitary solid waste landfill, which is 20 years old. The unsanitary solid waste landfill was subjected to pre-loading system over a period of 1 year, and 300 settlement monitoring provided the long term settlement data. This landfill contains relatively small amount of organic component, and therefore the initial stage of settlement was very small. The existing settlement models were examineed by comparing the observed behaviors of this site, and also they were used to predict the long-term settlement. Power Creep Law (PCL) model showed good agreement with the measured settlement obtained from the initial stage of the measurement, but other models showed satisfactory agreements after $50{\sim}70$ days of measurement.

• Journal of the Korean Society of Safety
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• v.15 no.2
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• pp.97-102
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• 2000

This paper presents the design, construction and performance of ground treatment to support road embankment on refuse landfill. Long-term settlement of refuse landfill is analysised by Sower and Yen/scanlon. As a results of site test, predicting settlement excess the allowable settlement and ultimate bearing capacity is not satisfied. The effectiveness of DDR(Deep Dynamic Replacement) is monitered by field tests (SPT, PBT, PMT) before, during and after construction of the stone columns. The ultimate bearing capacity for reinforced landfill by stone columns obtained from the in-situ test results has been compared with the existing theories. In municipal wastes landfill, settlement after treatment using stone column is satisfied to allowable residual settlement. Therefore, long-term stability can be gain in these cases.

• Journal of the Korean GEO-environmental Society
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• v.13 no.10
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• pp.5-13
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• 2012

In this study, the degrees of consolidation were evaluated by analyzing the long-term settlement measured at the 3 work sites with soft ground in Gyeongnam Area. The Hyperbolic, Hoshino and Asaoka method were used, which were focused on prediction of long-term settlement of land on the basis of field measurement data. And the applicability of the settlement prediction method according to the measurement periods was investigated by analyzing the degree of consolidation at the target areas after dividing the terms into early and latter parts. According to the results obtained at the early stage of consolidation, the Hyperbolic method appeared to be in the highest applicability level, which was followed by Asaoka and Hoshino method in the order of level. In the case of latter stage of consolidation, Asaoka method appeared to be in the highest applicability level, which was followed by and the Hyperbolic, Hoshino method in the order of level.

• Geomechanics and Engineering
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• v.2 no.2
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• pp.107-123
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• 2010

Ground settlements and pore pressure changes were monitored around a shallow tunnel constructed in clay till during the excavation and primary lining installation. The settlements above the tunnel continued to develop for up to 100 days after the primary lining installation. Triaxial compression tests were carried out to estimate the short-term and long-term deformation characteristics of the till. Numerical simulation was conducted to history match the field measurements, and thus, to quantify the settlements induced by ground stress relief, consolidation and creep. It was found that the surface settlements due to ground stress relief, consolidation and creep are 17, 12 and 71% of total settlement (about 44 mm), respectively. In addition, early installation of rigid concrete lining could be an effective means to reduce the settlement due to creep.

• Journal of the Korean Geotechnical Society
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• v.36 no.3
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• pp.5-14
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• 2020

The railway concrete track has been increasingly adopted for high-speed train such as KTX due to its high running stability, improved ride quality for the passengers, and low maintenance cost. However, excessive settlement of the railway concrete track has been monitored at embankment sections of the ◯◯ High-speed Line, resulting in the concerns on the safety of railway operation. In order to establish an effective maintenance plan for the concrete track railway exceeding the allowable residual settlement, it is essential to reasonably predict their long-term settlement behavior during the public period. In this study, we developed a model for predicting the long-term settlement behavior of concrete track using recurrent neural network (RNN) and examined the applicability of the developed model.