• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.1576-1580
• /
• 2006

The destruction of river and damage caused by flood are suddenly increasing due to the abnormal climate. In the investigation result about the damage, approximate 52% of the destruction of embankment are caused by earth work. Moreover, to recover conveyance of relief channel, bed sediment is dredged about 198 millions $m^3$ with 'the project of bed dredging'. So, the concern for bed sediment is the more increasing, the requiring high quality material for banking and the way for application of bed sediment are also the more increasing. In this paper, properties of bed sediment were analyzed through sedimentary mechanism analysis. Moreover, possibility to build embankment with bed sediment in 6 points which is in catchment of the Nak-dong river was also analyzed. At 6 points, which were selected to survey easily, sediment discharge was analyzed with formula. Moreover, size and permeability were analyzed and the feasibility for material of embankment was proposed. If bed sediment wasn't proper, complementary measures were proposed.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.03a
• /
• pp.649-658
• /
• 2009

The Aim of this development is the safety management network of embankment facilities using forecasting analysis algorism. Using this algorithm it is possible to predict a failure of embankment facilities in advance. therefore, it is necessary for making plans of a safety countermove. In this development we have researched the analysis method which could operate effectively the embankment facilities using real-time monitoring data from a remote sensing system and the safety managerial program using the algorithm from the analysis method developed.

• Journal of the Korean Geotechnical Society
• /
• v.28 no.5
• /
• pp.27-39
• /
• 2012

In this paper, a series of centrifuge tests were performed to evaluate the seepage characteristic of reinforced embankment. The centrifuge models simulated an actual embankment reinforced by enlargement of levee cross-section. The centrifuge models have the same conditions except the locations of enlargement with low permeable material : water-side and land-side. In addition, the prototype embankment is constructed on low permeable clay layer. In the case of water-side reinforcement, the reinforced zone makes water head down and the saturated zone of embankment propagates slowly. In the case of land-side reinforcement embankment, the saturated zone enlarged relatively faster but the amount of exit water at land-side toe was very small because of the land-side reinforcement zone. The low permeable clay foundation layer was being continuously saturated by the inflow from the embankment as well as the uplift flow from the permeable layer induced by the excess pore water pressure.

• Journal of Korea Water Resources Association
• /
• v.51 no.spc
• /
• pp.1161-1169
• /
• 2018

In this study, a new methodology was proposed to evaluate the flood vulnerability of river levee and to investigate the effect on the levee where the water level changes according to climate change. The stability of levee against seepage was evaluated using SEEP/W model which is two-dimensional groundwater infiltration model. In addition to the infiltration behavior, it is necessary to analyze the vulnerability of the embankment considering the environmental conditions of the river due to climate change. In this study, the levee flood vulnerability index (LFVI) was newly developed by deriving the factors necessary for the analysis of the levee vulnerability. The size of river levee was investigated by selecting the target area. The selected levees were classified into upstream part, midstream part and downstream part at the nearside of Seoul in the Han river, and the safety factor of the levee was analyzed by applying the design flood level of the levee. The safety ratio of the levee was analyzed by applying the design flood level considering the current flood level and the scenario of climate change RCP8.5. The degree of change resulting from climate change was identified for each factor that forms the levee flood vulnerability index. By using the levee flood vulnerability index value utilizing these factors comprehensively, it was finally possible to estimate the vulnerability of levee due to climate change.

• Journal of Korean Society of Disaster and Security
• /
• v.15 no.3
• /
• pp.1-14
• /
• 2022

Recently, the risk of water disasters are increasing due to climate change and the aging of river levees. Existing conventional river embankment inspections have many limitations due to the consumption of a lot of manpower and budget. Thus, it is necessary to establish a new monitoring and forecast/warning method for effective flood response. This study proposes the river levee health monitoring system by analyzing the relationship between river levee deformation and hydrological factors using Sentinel-1. The variance index calculated in this study was classified into 4 grades. And the levees collapse section was judged to be a high vulnerable point in which the variance rapidly increased based on the result of the rapid increase in soil moisture. In the future, it is expected that it will be possible to advance levee maintenance technology and improve national disaster management through the advancement of the existing levee management system and automated monitoring through the forensic method that combines remote technology.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.3
• /
• pp.13-19
• /
• 2012

Due to recent climate change, big typhoon and heavy rainfall happen frequently not only in Korea but also all over the world. It leads to collapse of levee by extraordinary flood. It lead to collapse of levees by extraordinary flood. These natural disasters give the life and property damages in near region. In this study, it was performed that a stability in levee using seepage analysis. It has been evaluated hydraulic gradient of exit zone according to variations in levee crest width, gradient. As a result, it showed that hydraulic gradient of exit zone was decreased due to increase of levee crest width and gradient, and it was evaluated that vertical hydraulic gradient was decreased than that of the horizontal hydraulic gradient.

• Journal of Korea Water Resources Association
• /
• v.42 no.7
• /
• pp.547-558
• /
• 2009

General reliability assessment of levees embankment is performed with safety factors for rainfall characteristics and hydrologic and hydraulic parameters, based on the results of deterministic analysis. The safety factors are widely employed in the field of engineering handling model parameters and the diversity of material properties, but cannot explain every natural phenomenon. Uncertainty of flood analysis and related parameters by introducing stochastic method rather than deterministic scheme will be required to deal with extreme weather and unprecedented flood due to recent climate change. As a consequence, stochastic-method-based measures considering parameter uncertainty and related factors are being established. In this study, a variety of dimensionless cumulative rainfall curve for typhoon and monsoon season of July to September with generation method of stochastic temporal variation is generated by introducing Monte Carlo method and applied to the risk assessment of levee embankment using reliability index. The result of this study reflecting temporal and regional characteristics of a rainfall can be used for the establishment of flood defence measures, hydraulic structure design and analysis on a watershed.

• Journal of the Korean Geotechnical Society
• /
• v.39 no.10
• /
• pp.27-39
• /
• 2023

To effectively manage flood risk, it is crucial to assess the stability of flood defense structures like levees under extreme flood conditions. This study focuses on the time-dependent probabilistic assessment of embankment slope stability when subjected to rapid water level drops. We integrate seepage analysis results from finite element analysis with slope stability analysis and employ Monte Carlo simulations to investigate the time-dependent behavior of the slope during rapid drawdown. The resulting probability of failure is used to develop fragility curves for the levee slope. Notably, the probability of slope failure remains low up to a specific water level, sharply increasing beyond that threshold. Furthermore, the fragility curves are strongly influenced by the rate of drawdown, which is determined through hydraulic analysis based on flood scenarios. Climate change has a significant impact on the stability of the water-side slope of the embankment due to water level fluctuations.

• Geophysics and Geophysical Exploration
• /
• v.13 no.1
• /
• pp.102-108
• /
• 2010

The internal structure of a river embankment must be delineated as part of investigations to evaluate its safety. Geophysical methods can be most effective means for that purpose, if they are used together with geotechnical methods such as the cone penetration test (CPT) and drilling. Since the dyke body and subsoil in general consist of material with a wide range of grain size, the properties and stratification of the soil must be accurately estimated to predict the mechanical stability and water infiltration in the river embankment. The strength and water content of the levee soil are also parameters required for such prediction. These parameters are usually estimated from CPT data, drilled core samples and laboratory tests. In this study we attempt to utilise geophysical data to estimate these parameters more effectively for very long river embankments. S-wave velocity and resistivity of the levee soils obtained with geophysical surveys are used to classify the soils. The classification is based on a physical soil model, called the unconsolidated sand model. Using this model, a soil profile along the river embankment is constructed from S-wave velocity and resistivity profiles. The soil profile thus obtained has been verified by geotechnical logs, which proves its usefulness for investigation of a river embankment.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.58 no.3
• /
• pp.91-100
• /
• 2016

Recently, lots of damages have been lost because large magnitude earthquakes were occurred in the world. It has been increased the number of earthquakes in Korea. It needs improvement required for the repair of deteriorated reservoirs, reinforcement and raised reservoir coping with climate change and earthquake. This study aims to investigate the seismic behavior of deterioration reservoir levee using dynamic centrifugal model test. Therefore, two case tests in centrifugal field of 60 g, the result has provided the influence on the acceleration response, displacement, settlement and the pore water pressure of the reservoir with earthquakes. From the results larger displacement and acceleration response at the front side of reservoir embankment with poor-fabricated core in seismic condition may degrade overall stability. Reasonable reinforcement method of the raised reservoir embankment is required for ensuring long-term stability on earthquake.