• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.263-274
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• 2018

In this study, the applicability and external/internal stability of a MSEW abutment with a slab were investigated. Structural analysis of slab bridges between 10 ~ 20.0 m and thicknesses of 0.7 ~ 0.9 m was carried out to calculate the reaction forces due to dead and live loads acting on the bridge supports. The slab bridge with a length of 20.0 m satisfied the allowable contact pressure of 200 kPa for the true MSEW abutment. Because the external stability of the true MSEW abutment was dominated by the geometry of the MSE wall, the change in the factor of safety due to the load of the super-structure is small. Because the stiffness of the foundations is fixed and the load of the super-structure is increased, the factor of safety of the bearing capacity was reduced. As the load of the super-structure was increased, the horizontal earth pressure of the true MSEW abutment increased greatly. As a result, the pullout and fracture of the uppermost reinforcement, which are the factors of safety, did not meet the design criteria. Therefore, it is necessary to increase the pullout resistance and the long-term allowable tensile force of the reinforcement placed on the top of the reinforced soils to ensure efficient design and performance of a true MSEW abutment.

• Journal of the Korean Geosynthetics Society
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• v.7 no.2
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• pp.41-47
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• 2008

This paper describes the results of model experiments in the laboratory, which were conducted to assess the behavior characteristics of geosynthetic reinforced soil walls according to different surcharge loads and reinforcement types. The model walls were built in the box having dimension, 100 cm tall, 140 cm long, and 100cm wide. Three types of geosynthetics, geonet, geogrid A and geogrid B, are used as the reinforcements. Decomposed granite soil (SM) was used as a backfill material. Seven model walls are constructed and tested. After the construction of the model wall, the LVDTs are installed to obtain the displacements of the wall face. As the results of the model tests, the maximum horizontal displacements of the model walls occurred due to uniform surcharge pressure were measured at the 0.7H from the bottom of the wall. The more the reinforcement strength increases, the more the wall displacements decrease, and also the reduction ratio of the wall displacement decrease with increasing the surcharge pressure.

• Journal of the Korean Geosynthetics Society
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• v.11 no.1
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• pp.65-75
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• 2012

Since the modem reinforced soil wall technology was introduced in domestic civil engineering society in the year 1980, the reinforced soil walls have been extensively used because these technologies have advantages such as economical efficiency, graceful appearance, and easy construction. This paper describes the application of reinforced soil wall, design criteria, and construction problems. Many cases of troubles, which include a severe deformation of facing, cracks of facing block, overall sliding failure and so on, have been reported. Inappropriate design and construction management mainly induce these problems. The technological level of design and quantity control for reinforced soil wall is not sufficiently supported to cope with the growth quantity of reinforced soil wall construction market and the increasing number of construction companies. The unified standard design and construction criteria of reinforced soil wall should be established with the detail consideration of overall performance and stability. The quality control of design and construction, and cost of construction must be seriously executed to construct a high quality of reinforced soil wall.

• Journal of the Korean Geosynthetics Society
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• v.12 no.1
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• pp.109-114
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• 2013

This paper describes the global stability of the reinforced earth wall, which was collapsed by heavy rainfall. The seepage analysis was conducted to confirm the change effect of groundwater level on slope with reinforced earth wall. The seepage analysis result confirmed that the change of groundwater level is greatly influenced by rainfall. According to the change of groundwater level, the global stability analysis with reinforced earth wall was conducted based on the results of seepage analysis. The safety factor of the slope was 0.476 when the wall is collapsed firstly. The collapse cause analyzed that soil strength was weaken because the ground was saturated by continuous rainfall. Therefore, the global stability, which is considered heavy rainfall, should be conducted at design and construction of reinforced earth wall.

• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.257-265
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• 2012

Since the collapse of MSE walls frequently occurs due to the rainfall, it is necessary to analyze the behavior of MSE wall depending on the characteristics of rainfall and the properties of permeability of backfill. In order to understand the behavior of MSE wall depending on the characteristics of rainfall and the properties of permeability of backfill, finite element analyses were performed on the typical MSE wall. With varying ratio of saturated permeability to rainfall intensity, porepressures, displacements and factor of safety were analyzed. As the ratio of the saturated permeability to rainfall intensity increases, the global factor of safety is found to increase. Based on the analyses, the use of permeability of backfill with $2.56{\times}10^{-5}m/sec$ is desirable considering the characteristics of rainfall in Korea.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.179-188
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• 2018

A new style of panel-type reinforced earth wall is a more integrated structure by connecting the geosynthetic strip reinforcement with a folding groove directly to the front panel through C-shaped insertion hole embedded in the panel. In this study, field measurements were conducted on two reinforced earth walls constructed at different sites to assess the field applicability and structural stability of the new style of panel-type reinforced earth wall. The horizontal displacement of the front panel, tensile deformation of the geosynthetic strip reinforcement, and horizontal earth pressure acting on the panel were measured and analyzed through the field measurements. According to the field measurements, after completion of the reinforced earth wall construction, the maximum horizontal earth pressure applied to the front panel was less than two-thirds of the Rankine earth pressure, and the maximum horizontal displacement of the front panel was less than 0.5% of the wall height, and the maximum tensile strain generated on the reinforcement was less than 1.0%. Therefore, it was found that two reinforced earth walls constructed at different sites remained stable.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.195-196
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• 2017

연약한 지반 위에 시공되는 보강토 옹벽이 연약지반의 침하에 대하여 안정성을 분석하고 지반의 처리를 어떻게 하는 것이 향후 재난발생을 예방할 수 있는지에 대하여 침하량을 분석하고 대처 방법에 대하여 분석하였다.

• Journal of the Korean Geosynthetics Society
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• v.7 no.3
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• pp.9-16
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• 2008

This paper is concerned with the numerical evaluation of the failure behavior of reinforced soil walls based on the elasto-plastic theory. At first, the basic analysis on the failure behavior of reinforced soil walls are discussed. Parametric study of the major factors influencing the failure behavior is conducted by FEM. The objectives are to identify and evaluate the major facts influencing the failure mode of reinforced soil walls. The results of the parametric study on the failure behavior due to soil friction angle, reinforcement type, and reinforecement length are analysed.

• Journal of the Korean Geosynthetics Society
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• v.8 no.1
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• pp.11-18
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• 2009

This paper presents a comparative study of reinforced soil slope by using LEM and SSR-FEM. Current analysis methods for reinforced soil wall are based on LEM. SSR-FEM assumes a reduction of soil strength by a factor to reach a critical state prior to failure based on continuum mechanics. In this study the comparisons are concerned with the factor of safety and the potential failure surface in reinforced soil wall. We investigated the stability of the reinforced soil wall with a slope of $60^{\circ}$ by LEM and SSR-FEM. The comparisons indicated good performance of the SSR-FEM on stability analysis of reinforce soil wall.

• Geotechnical Engineering
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• v.11 no.2
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• pp.107-120
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• 1995

The purpose of this study is to investigate the effects of fiber on engineering properties of Fiber-Reinforced Soil. Engineering properties of soil reinforced with discrete randomly oriented inclusion depend on soil density, particle size, grading, fiber length, tensile strength and stiffness of fiber, mixing ration of fiber, confining stress, etc.. in this paper, the influence of fiber shape, fiber length, fiber diameter, fiber content, cement content and curing duration on engineering characteristics(compaction, shear & permeability) were evaluated for typical soils produced from construction works through uniaxial compression tests and triaxial compression tests. From the experimental results, it was also investigated if there is an optimal range of fiber lengths and fiber contents for the tested soils and tested mono-filament fibers.