• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.862-870
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• 2010

This thesis has been researched on optimized design method for the total cross section of embankment considering the fact that the size of embankment cross section is directly related with economic efficiency when dam designing. In general, embankment cross section of fill dam is either determined by cohesion and angle of internal friction, a strength parameter of embankment materials or by permeability of embankment. Therefore the size of embankment cross section depending on strength parameter of embankment materials was determined by using MIDAS-GTS program through stress-seepage coupled analysis at the time of fill dam design. As a result, determination of embankment cross section was more affected by the size of central core and permeability rather than by slope stability by shear strength and it was revealed that in case of embankment height being over 20m, stability against infiltration and slope action could be secured only when embankment slope is at least over 1:2.5. In addition, it was also revealed that in case of making the size of central core exceeding specification standard, total cross section of embankment could be reduced considerably and at the time of embankment design, adequate size and appropriateness of embankment cross section could be determined with referring the table suggested by this study.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.749-758
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• 2010

Embankment Slope (or Fill Slope) is defined as artificial slope formed by the filling of soil or rocks on the original ground. Recently a lot of embankment failures and collapse has occurred due to the increase of torrential rainfall and typhoons. Embankment collapse has lead to a great loss of lives and property therefore there is a need to establish a systematic embankment slope management system that will handle the maintenance and repair of risky embankment slopes. The objective of this study is to establish an "Embankment Slope Management Method" for embankment slopes located along national highways all over Korea. The method for field investigation of embankment slopes was recommended and the system for investment priority determination was also developed. The factors that lead to the collapse of embankment slopes caused by natural calamities were also determined through the initial survey of embankment slopes located along river fronts and mountainous areas.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.956-962
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• 2009

A high embankment is generally constructed by dividing into several sub-embankments. Unlike any soil embankment, a rock embankment is constructed by means of dynamic compaction. Such a sub-embankment and dynamic compaction may induce an increase of pressure at the lower part of embankment and cause a different behavior of ground from initial status. In this study, settlement of a high rock embankment is estimated using a hyperbolic model taking into construction history. The results from prediction are compared with those obtained from field measurements and large plate loading tests.

• Geomechanics and Engineering
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• v.6 no.1
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• pp.17-31
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• 2014

This paper investigates the development of failure surfaces induced by an embankment on soft marine clay deposits and the characteristics of such surfaces through numerical simulations and its comparative study with monitoring results. It is well known that the factor of safety of embankment slopes is closely related to the vertical loading, including the height of the embankment. That is, an increase in the embankment height reduces the factor of safety. However, few studies have examined the relationship between the lateral movement of soft soil beneath the embankment and the factor of safety. In addition, no study has investigated the distribution of the pore pressure coefficient B value along the failure surface. This paper conducts a continuum analysis using finite difference methods to characterize the development of failure surfaces during embankment construction on soft marine clay deposits. The results of the continuum analysis for failure surfaces, stress, displacement, and the factor of safety can be used for the management of embankment construction. In failure mechanism, it has been validated that a large shear displacement causes change of stress and pore pressure along the failure surface. In addition, the pore pressure coefficient B value decreases along the failure surface as the embankment height increases. This means that the rate of change in stress is higher than that in pore pressure.

• Geomechanics and Engineering
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• v.8 no.4
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• pp.511-521
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• 2015

It is a common failure type that high-filled embankment slope sideslips. The deformation mechanism and factors influencing the sideslip of embankment slope is the key to reduce the probability of this kind of engineering disaster. Taking Liujiawan high-filled embankment slope as an example, the deformation and failure characteristics of embankment slope and sheet-pile wall are studied, and the factors influencing instability are analyzed, then the correlation of deformation rate of the anti-slide plies and each factor is calculated with multivariate linear regression analysis. The result shows that: (1) The length of anchoring segment is not long enough, and displacement direction of embankment and retaining structure are perpendicular to the trend of the highway; (2) The length of the cantilever segment is so large that the active earth pressures behind the piles are very large. Additionally, the surface drainage is not smooth, which leads to form a potential sliding zone between bottom of the backfill and the primary surface; (3) The thickness of the backfill and the length of the anti-slide pile cantilever segment have positive correlation with the deformation whereas the thickness of anti-slide pile through mudstone has a negative correlation with the deformation. On the other hand the surface water is a little disadvantage on the embankment stability.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.507-534
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• 2015

The present work investigates the behavior of the embankment models resting on soft soil reinforced with ordinary and stone columns encased with geogrid. Model tests were performed with different spacing distances between stone columns and two lengths to diameter ratios (L/d) of the stone columns, in addition to different embankment heights. A total number of 42 model tests were carried out on a soil with undrianed shear strength $${\sim_\sim}10kPa$$. The models consist of stone columns embankment at s/d equal to 2.5, 3 and 4 with L/d ratio equal 5 and 8. Three embankment heights; 200 mm, 250 mm and 300 mm were tested for both tests of ordinary (OSC) and geogrid encased stone columns (ESC). Three earth pressure cells were used to measure directly the vertical effective stress on column at the top of the middle stone column under the center line of embankment and on the edge stone column for all models while the third cell was placed at the base of embankment between two columns to measure the vertical effective stress in soft soil directly. The performance of stone columns embankments relies upon the ability of the granular embankment material to arch over the 'gaps' between the stone columns spacing. The results showed that the ratio of the embankment height to the clear spacing between columns (h/s-d) is a key parameter. It is found that (h/s-d)<1.2 and 1.4 for OSC and ESC, respectively; (h is the embankment height, s is the spacing between columns and d is the diameter of stone columns), no effect of arching is pronounced, the settlement at the surface of the embankment is very large, and the stress acting on the subsoil is virtually unmodified from the nominal overburden stress. When $(h/s-d){\geq}2.2$ for OSC and ESC respectively, full arching will occur and minimum stress on subsoil between stone columns will act, so the range of critical embankment height will be 1.2 (h/sd) to 2.2 (h/s-d) for both OSC and ESC models.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1036-1041
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• 2008

In order to analysis the reason of sliding failure in embankment slope under construction in soft soil area, a model section located in Gimhae Region in Gyeongsangnam-Do, where the sliding failure had been occurred during embankment works in soft soil area, had been selected. This area had been firstly treated with the Pack Drain Method, and additional embankment works of 9.7 meters out of total 14 meters in thickness had been under construction. The results of analysis showed that the reason of sliding failure were overspeed in embankment construction and the overestimation of design factors in calculating strength of each layer of embankment and poor management and inaccuracy reading of measurement devices.

• Geomechanics and Engineering
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• v.21 no.1
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• pp.35-51
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• 2020

In this study, the seismic response analysis of embankment dams was investigated through numerical modeling. The seismic behavior of dams under main earthquake records and wavelet-based records were studied. Earthquake records were decomposed using de-noising method (DNM) and down-sampling method (DSM) up to five levels. In decomposition process, low and high frequencies of the main earthquake record were separated into two signals. Acceleration response, spectral acceleration, and Fourier amplitude spectrum at the crest of embankment dams under different decomposition levels were evaluated. The seismic behavior under main and decomposed earthquake records was compared. The results indicate an acceptable agreement between the seismic responses of embankment dams under wavelet-based decomposed records and main earthquake motions. Dynamic analyses show that the DNM-based decomposed earthquake records have a better performance compared to DSM-based records. DNM-based records up to level 4 and DSM-based records up to level 2 have a high accuracy in assessment of seismic behavior of embankment dams. The periods corresponding to the maximum values of acceleration spectra and the frequencies corresponding to the maximum values of Fourier amplitude spectra of embankment dam crest under main and decomposed records are in good agreement. The results demonstrate that the main earthquake records can be replaced by wavelet-based decomposed records in seismic analysis of embankment dams.

• Geomechanics and Engineering
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• v.31 no.3
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• pp.319-328
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• 2022

Ensuring the integrity of a country's infrastructure is necessary to protect surrounding communities in case of disaster. Embankment dam systems across the US are an essential component of infrastructure, referred to as lifeline structures. Embankment dams are crucial to the survival of life and if these structures were to fail, it is imperative that states be prepared. Southern California is particularly concerned with the stability of embankment dams due to the frequent seismic activity that occurs in the state. The purpose of this study was to create a numerical model of an existing embankment dam simulated under seismic loads using previously recorded data. The embankment dam that was studied in Los Angeles, California was outfitted with accelerometers provided by the California Strong Motion Instrumentation Program that have recorded strong motion data for decades and was processed by the Center for Engineering Strong Motion Data to be used in future engineering applications. The accelerometer data was then used to verify the numerical model that was created using finite element modeling software RS2. The results from this study showed Puddingstone Dam's simulated response was consistent with that experienced during previous earthquakes and therefore validated the predicted behavior from the numerical model. The study also identified areas of weakness and instability on the dam that posed the greatest risk for its failure. Following this study, the numerical model can now be used to predict the dam's response to future earthquakes, develop plans for its remediation, and for emergency response in case of disaster.

• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.243-252
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• 2013

This study was carried out to investigate safety evaluation of agricultural reservoirs due to raising the embankment. The seepage analysis and large-scale model test were performed to compare and analyze the pore water pressure(PWP), leakage quantity, settlement and piping phenomenon in the inclined core type and the vertical core type embankments. The PWP after raising the embankment showed smaller than before raising the embankment and the stability for piping after raising the embankment. The allowable seepage quantity and the allowable leakage for the steady state and transient conditions is within the range of safe management standard. After raising the embankment in the inclined core, there was no infiltration by leakage. For the vertical core, the PWP showed a large change by faster infiltration of pore water than in the inclined core. In a rapid drawdown, inclined core was remained stable but the vertical core showed a large change in PWP. Settlement after raising the embankment showed larger amounts of settlement than before raising the embankment. The leakage quantity before raising the embankment and the inclined core type showed no leakage. From the result, an instrument system that can accurately estimate a change of PWP shall be established for the rational maintenance and stabilization of raising the embankment for agricultural reservoirs.