• Earthquakes and Structures
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• v.7 no.6
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• pp.909-935
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• 2014

The seismic characteristics of two semi-gravity reinforced concrete cantilever retaining walls are examined via an experimental program using an outdoor shake table (one with and the other without concrete masonry sound wall on top). Both walls are backfilled with compacted soil and supported on flexible foundation in a steel soil container. The primary damages during both tests are associated with significant lateral displacements of the wall caused by lateral earth pressure; however, no collapse occurs during the tests. The pressure distribution behind the walls has a nonlinear trend and conventional methods such as Mononobe-Okabe are insufficient for accurate pressure estimation.

• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.97-106
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• 2003

In this study, the effect of temperature and soil confining stress on geosyntheic stress-strain properties was quantified by performing the temperature dependent confined tension tests for four types of geosynthetic including woven geotextile, composite, geomembrane and geogrid specimen. Temperature instrumentation on the GRS-retaining wall constructed in Jaechon-shi area was also performed to examine the a seasonal temperature variation of geosynthetic reinforcements in the backfill. Based on the test results, a comparison was made between unconfined and confined moduli far each temperature to quantify the soil confinement and temperature effect on stress-strain properties. And it was also proposed that the simple expressions for the secant moduli of geosynthetics as a function of temperature and confining stress on geosynthetics. As a result of the FDM analysis of GRS-retaining wall, the method of considering the effect of temperature and confining stress on geosynthetic reinforcements when performing the FDM analysis of GRS-retaining wall was proposed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.3
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• pp.33-42
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• 2005

The bearing methods using pile of steel itself or reinforced concrete has been applying which in excavated depth was not deep. Also, the retaining wall as resisting structure to lateral force has taken weakness that the cure periods of concreted is long. Recently, with the material cost of steel, the application of cement is more increasing trend. In this study, the design methods of earth retaining and retention wall within the pre-casted concrete pile, PHC(Pretentioned spun High strength Concrete piles), was proposed which in the ground condition of excavated depth was not deep. The typical ground conditions, cohesive and non-cohesive soil, was considered as follows; soil strength as internal friction angle and UU(Undrained Unconsolidation triaxial test) strength, soil reaction and stabilization of structures. The application of design methods could be confirmed through the comparing and analyzing between measured data and utility software for the design.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.06a
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• pp.13-19
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• 2001

The use of reinforced soil have been increased due to it's cost effectiveness, flexibility and so on. In this study, a full-scale reinforced soil with rigid facing were constructed to investigate the soil pressure variation of reinforcing system. The results of soil pressure during backfill construction are described. The influence of facing stiffness on soil pressure is addressed. The results show that lateral earth pressures on the wall are active state during backfill. It is obtained that the lateral soil pressure highly depends on the installation condition of pressure cell and construction condition. Long-term measurement will be followed to verify the design assumptions with respect to the distribution of lateral stress on the facing.

• Journal of the Korean Geosynthetics Society
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• v.10 no.4
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• pp.105-112
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• 2011

This paper presents the numerical modelling technique for modeling the time-dependent behavior of geosynthetic reinforced soil wall under a sustained load. The applicability of power law-based creep models for modeling the creep deformations of geogrid and reinforced soil was first examined. The modeling approach was then used to simulate the long-term performance of a geosynthetic reinforced soil wall used in a bridge abutment. The results indicated that the power law-based models can be effectively used for modelling the long term behavior of geosynthetic reinforced walls under sustained loading. In addition, it was shown that, when using creep deformation susceptible backfill soils, the abutment wall and the sill beam may experience deformations exceeding allowable limits. Practical implications of the findings from this study are discussed in great detail.

• Journal of the Korean Geosynthetics Society
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• v.5 no.3
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• pp.45-52
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• 2006

The collapsed cases are more and more increasing at the large scaled structures because of increasing of the risk due to natural disasters. The measuring instrument such as inclinometer, total station on reinforced-soil retaining wall has been used that displacement, settlement for stability assessment, maintenance and management of it. But because these has gotten many instability measuring factors for stability analysis of RRW, new system needs to complement disadvantage of existing system. In this study, we considered a application of Visual Monitoring System (VMS) to measure a displacement in face of wall through Lab. test about block assembly of segmental retaining wall during load test.

• Geomechanics and Engineering
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• v.6 no.2
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• pp.99-115
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• 2014

Uncertainties in design variables and design equations have a significant impact on the safety of geotechnical structures like retaining walls and slopes. This paper presents a possible framework for obtaining the partial safety factors based on reliability approach for different random variables affecting the stability of a reinforced concrete cantilever retaining wall and a slope under static loading conditions. Reliability analysis is carried out by Mean First Order Second Moment Method, Point Estimate Method, Monte Carlo Simulation and Response Surface Methodology. A target reliability index ${\beta}$ = 3 is set and partial safety factors for each random variable are calculated based on different coefficient of variations of the random variables. The study shows that although deterministic analysis reveals a safety factor greater than 1.5 which is considered to be safe in conventional approach, reliability analysis indicates quite high failure probability due to variation of soil properties. The results also reveal that a higher factor of safety is required for internal friction angle ${\varphi}$, while almost negligible values of safety factors are required for soil unit weight ${\gamma}$ in case of cantilever retaining wall and soil unit weight ${\gamma}$ and cohesion c in case of slope. Importance of partial safety factors is shown by analyzing two simple geotechnical structures. However, it can be applied for any complex system to achieve economization.

• Journal of the Korean Geosynthetics Society
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• v.16 no.2
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• pp.165-174
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• 2017

There are natural disasters caused by abnormal climate in the world. In particular, there are frequent disasters such as floods and landslides caused by rainfall in summer. Rainfall will have a major impact on the stability of a retaining wall. If drainage during rainfall activities within the retaining wall is not made properly, permeated water brings a significant increase in pore pressure inside of the backfill soil and reduces the shear strength of the soil. Therefore, research how to install the drainage layers to reduce the infiltrated water inside of the backfill soil is very necessary. In this study, we performed a numerical modeling to find the optimum installation conditions of the location and number of drainage layer related to stability of the reinforced retaining wall during rainfall installed geosynthetics.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.131-142
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• 2009

Geosynthetic reinforced soil walls are well recognized alternatives to conventional retaining walls due to many advantages in terms of ease of construction, economy, and aesthetics, among others. In recent years, the use of back-to-back (BTB) geosynthetic reinforced soil walls has been increasing for roadway and railway construction. However, there are insufficient studies concerning the behavior of BTB type geosynthetic reinforced soil walls. In this study a series of finite element analysis were performed for BTB walls with various wall geometry and reinforcement distribution. The results were then analyzed to relate the wall geometry and reinforcement distribution and the performance of BTB walls. Optimum reinforcement pattern was also investigated.

• Journal of the Korean Geosynthetics Society
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• v.15 no.1
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• pp.11-19
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• 2016

This paper presents the results of a scale model test to the effect of heat exchanger drainage method in retaining wall of weathered granite soil. Purpose to rise in the temperature of the heat wires inside the weathered granite soil is preventing the collapse of the retaining wall and drainage smoothly moved to the drainage layer. Especially using a spray gun to simulate the rainfall since the rainfall drainage work is important for the rainfall effect on soil, find the difference about displacement of the retaining wall, change of volume water content, drainage, earth pressure and change in the strain of the geosynthetic was effected to heat exchanger within the soil. The result from applying the heat exchanger method decreased the earth pressure and displacement of the wall and increased drainage of water.