• 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.

• Journal of the Korean Geotechnical Society
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• v.18 no.3
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• pp.61-72
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• 2002

This paper presents the results of investigation on the behavior of soil-reinforced segmental retaining walls in tiered arrangement using the finite element method of analysis. 2D finite element analyses were performed on tiered walls with two levels of offset distance. Cases with equivalent surcharge as suggested by the NCMA design guideline were additionally analyzed in an attempt to confirm the appropriateness of the equivalent surcharge model adopted by NCMA. Deformation characteristics of a tiered wall with small offset distance suggest a compound mode of failure and support current design approaches requiring a global slope stability analysis for design. Also revealed is that the interaction between the upper and lower walls significantly affects not only the performance of the lower wall but also the upper wall, suggesting that the upper walls should also be designed with due consideration of the interaction.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09c
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• pp.3-10
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• 2010

Case study was carried out on the interpretation of the mechanical behavior of a severely damaged reinforced earth wall comprising geotextile with the concrete panel facing. In this part I, the outline of the damaged reinforced earth wall is in detail described. The background and cause of the damage are discussed based on the results of site investigation. The engineering properties of the fill were examined by performing various in-situ and laboratory tests, including the surface wave survey (SWS), PS-logging, RI-logging, soaking test, the direct shear box (DSB) test, bender element (BE) test, etc. The background as well as the cause for the damage of the wall may be described such that i) a considerable amount of settlement took place over a 3m thick weak soil layer in the lower part of the reinforced earth due to seepage of rainfall water, ii) the weight of the upper fill was partially supported by the geo-textile hooked on the concrete panels (n.b., named conveniently "hammock state" in this paper), and iii) the concrete panels to form the hammock were severely damaged by the unexpectedly large downwards compression force triggered by the tension force of the geotextile. The numerical simulation for the hammock state of the wall, together with counter-measures to re- stabilize the wall is subsequently described in Part II.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.167-170
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• 2003

• Journal of Environmental Science International
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• v.16 no.9
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• pp.1099-1102
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• 2007

This paper presents eco-friendly planting method to overcome the problems of existing concrete retaining wall and gabion retaining wall, respectively, based on the examination on existing concrete and gabion retaining wall. Prior to doing this, proper design method was provided through pull out test. Planting method using gabion metal net and L shape green net retaining wall were compared and analyzed. According to this study, it is confirmed that reduction of construction period and economical profit in construction can be achieved by both manufacturing at the factory and self procurement at the job site as well as the use of metal net, which is applied as a substitution of existing strengthening material. For the effect of planting method, the use of L shape green net retaining wall shows superiority to environment-friendly gabion retaining wall in its ability to rootage and germination of the grass. The L shape green net retaining wall had excellent performance in helping rootage of grass and prevention of soil leakage, and even if raining period, remarkable damage of planting mat does not occur when planting mat is applied.

• 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 Geotechnical Society
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• v.18 no.5
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• pp.169-178
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• 2002

The stress~strain characteristics of geosynthetics reinforced clayey soil were investigated by triaxial compression tests. All the tests were peformed either on unreinforced or reinforced soils under fully drained condition after having been consolidated isotropically or anisotropically to the required level of effective stresses by the small increment of 0.05kgf/$cm^2$. The anisotropically consolidated drained tests were performed to simulate the in-situ condition of reinforced soil structures such as reinforced soil wall, abutment and embankment which are generally in the anisotrpic state. From a series of tests it was ffund that the behavior of the anisotropically consolidated reinforced clayey soils was very different from stress~strain characteristics of consolidated reinferced clayey soils. It was found especially that the initial Young's moduli of anisotropically consolidated reinforced clayey soils were higher than those of isotropically consolidated reinforced clayey soils. It was found also that the reinforcement effect in anisotropically consolidated reinforced soils developed at a much lower level of axial strain(0.01%) compared with isotropically consolidated ones(about 1.0~5.0%).

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1562-1571
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• 2005

The use of geogrid for SRW systems and bridge abutment has increased rapidly over the past 10 years in Korea. The concept of segmental retaining walls and reinforced soil is very old and for example The Ziggurats of Babylonia(i.e. Tower of Babel) were built some 2,500 to 3,000 years ago using soil reinforcing methods very similar to those described in current design. Modern SRW(Semental Retaining Wall) units were introduced in 1960's as concrete crib retaining wall systems. In this paper, the friction properties between segmental concrete units and geogrid are investigated by performing various tests.

• 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.

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.55-66
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• 2011

This paper presents the results of an investigation on the failure mechanism of geosynthetic reinforced soil walls in back-to-back configuration using 1-g reduced-scale model tests as well as discrete element method-based numerical investigation. In the 1-g reduced scale model tests, 1/10 scale back-to-back walls were constructed so that the wall can be brought to failure by its own weight and the effect of reinforcement length on the failure mechanism was investigated. In addition, a validated discrete element method-based numerical model was used to further investigate the failure mechanism of back-to-back walls with different boundary conditions. The results were then compared with the failure mechanisms defined in the FHWA design guideline.