• Journal of the Korean Society for Railway
• /
• v.3 no.2
• /
• pp.84-91
• /
• 2000

The general concept of reinforced roadbed in the high-speed railway is to cope with the soft ground for the bearing capacity and settlement of foundation soil. The cyclic plate load tests were performed to determine the behavior of reinforced ground with multiple layers of geogrid underlying by soft soil. With the test results, the bearing capacity ratio, elastic rebound ratio, subgrade modulus and the strain of geogrids under loading were investigated. Based on these plate load tests, laboratory model tests under cyclic loading were conducted to estimate the effect of geogrid reinforcement in particular for the high-speed rail roadbed. The permanent settlement and the behavior of earth pressure in reinforced roadbed subjected to a combination of static and dynamic loading are presented.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.1
• /
• pp.25-34
• /
• 2014

The aim of this study is to analyze the mechanical characteristics and settlement feature of the composite ground with structural form changes. The laboratory model test is a soil tanker to be contained with clay and grid form improved soil, which is conducted in total 9 case with the uniaxial compressive strength of improved soil and replacement ratio of improved soil. The numerical analysis for variation of stress distribution ratio with depth was performed in the same conditions which are the laboratory model test. As a result, stress distribution ratios in mid and high replacement ratio are increasing and settlement is decreasing, except low replacement ratio. This study is presented for form effect ratio and settlement reduction factor with change of structure form, which is able to be helpful in further research and reference for change of structural forms at composite ground.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.96-102
• /
• 2006

Because of the increasing need to use clayey soil as the backfill in reinforced soil structures and embankment material, nonwoven geotextiles with the drain capability have been receiving much attention. However, there are few studies of the deformation behavior of nonwoven geotextiles at geosynthetics reinforced soil structures in the field because the nonwoven geotextile, which has low tensile stiffness and higher deformability than geogrids and woven geotextiles, is difficult to measure its deformation by strain gauges and to prevent the water from infiltrating. This study proposes a new, more convenient method to measure the deformation behaviour of nonwoven geotextile by using a strain gauge; and examines the availability of the method by conducting laboratory tests and by applying it on two geosynthetics reinforced soil (GRS) walls in the field. A wide-width tensile test conducted under confining pressure of 7kPa showed that the local deformation of nonwoven geotextile measured with strain gauges has a similar pattern to the total deformation measured with LVDT. In the field GRS walls, nonwoven geotextile showed a larger deformation range than the woven geotextile and geogrid; however, the deformation patterns of these three reinforcement materials were similar. The function of strain gauges attached to nonwoven geotextile in the walls works normally for 16 months. Therefore, the method proposed in this study for measuring nonwoven geotextile deformation by using a strain gauge proved useful.

• Journal of the Korean Geotechnical Society
• /
• v.29 no.11
• /
• pp.107-118
• /
• 2013

Geosynthetic reinforced soil (GRS) walls have been increasingly applied recently due to its numerous geotechnical engineering applications. However failure occurs in some cases of constructed GRS walls. These GRS wall failures are mostly due to the unpredictable characteristics of intensive rainfall. Hence, the need for new and innovative ideas for rehabilitation methods has been getting attention. This paper introduces a case study for the design and restoration method of collapsed GRS wall using Limit equilibrium and Numerical Analyses. Restoration method includes: (1) soil nailing without backfill excavation and (2) reconstruction with GRS wall after collapsed backfill excavation. Analyses results show minimal horizontal displacements and shear strain on the reinforced concrete facing for the restoration case with soil nailing. On the other hand, horizontal displacements are developed in the middle of the mortar block facing and shear strains are developed at the bottom facing with spiral curves for the reconstructed GRS wall after collapsed backfill excavation. Therefore, the collapsed GRS wall was restored with the soil nailing without backfill excavation and its construction procedures are discussed in this paper.

• Journal of the Korean Geosynthetics Society
• /
• v.5 no.4
• /
• pp.35-42
• /
• 2006

This paper describes a field experience on geogrid-reinforced soil walls rising up to 29.5m in height. Since experiences of design and construction on very high-raised geogrid reinforced soil wall were limited, thorough design and construction management was performed for safe construction of the wall. Regarding design of the wall, both internal and external stabilities were examined based on the design guideline specified by FHWA and overall slope stability analyses were performed by using Bishop simplified method. Moreover, a series of instrumentations were performed. The results of instrumentation for two tiered reinforced soil wall showed that not only the deformations of both the wall face and the reinforcement but also the horizontal earth pressures acting on the wall facing were very small. These results indicate that the reinforced soil wall technology can be applied successfully for high-raised tiered wall more than 20m heights and FHWA design guideline is very conservative for that large wall.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.3
• /
• pp.457-462
• /
• 2022

This study is about the case applied of a shallow foundation reinforcement method for a low/mid-rise building where a relatively small load is applied by using a soil stabilized material that utilizes recycled resources. First, laboratory mixing test was conducted for four mixing ratios in order to derive the optimal mixing ratio in the field. Using the derived optimal mixing ratio, it was applied as a shallow foundation for the building in the field. The field application method used a simple process of compaction by the soil mixedure with the original soil and the soil stabilized material in the field. After field application, a plate bearing test was performed on one original ground and two improved ground to confirm the allowable bearing capacity. As a result of checking the bearing capacity, it was found that sufficient bearing capacity was exhibited.Therefore, it was confirmed that it can be used as a shallow foundation for the building.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.6C
• /
• pp.385-393
• /
• 2006

Soil nailing is a reinforcement method used for stabilizing excavated walls or slopes. Due to its much advantages such as ease of construction and economical efficiency, use of soil nailing is increased. However, the soil nail has much disadvantages for use in urban area. The soil nail needs to be installed inevitably beyond private land boundary, which causes rent for use. For this reason, removable soil nailing system was developed. However, the removal rate of this system is just about 50￠¦70%. To resolve this problem, the Fiber Reinforced Plastic (FRP) soil nailing system which does not need to be removed and allows for the installation beyond private land, is developed. In this paper, through theoretical and experimental studies in laboratory and field such as prototype tests, pullout tests, we evaluate the stability and behavior characteristics of the FRP soil nailing system. And, numerical analyses using FLAC2D were performed with respect to various soil conditions, where prototype test for excavation wall and pullout tests were carried out. As a result of this study, the FRP soil nailing systems show similar behavior characteristics with those of removable soil nailing system. Finally, considering the serviceability and mechanical stability of FRP soil nailing systems, it is enough to be used as a good alternative of general soil nailing system.

• Journal of Korean Association for Spatial Structures
• /
• v.15 no.2
• /
• pp.79-86
• /
• 2015

This study investigated the embedded depth of guardrail posts through 3-D soil material model and carried out evaluation of the dynamic performance of guard rail. In order to calculate for embedded depth of sloping ground, displacement of guardrail posts is analyzed according to the embedded depth of experiment variables. Through the static test of guardrail posts, the maximum deflection was found to decrease the interval. By performing the dynamic test using the Bogie Car, that is confirmed the elastic modulus of the soil occuring the maximum deflection. Guardrail posts is considered to need for further reinforcement in the larger slope than the plains. This study researched about maximum displacement and deviation velocity through dynamic performance of guardrail system and conducted analysis about protection performance evaluation of passenger.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.905-917
• /
• 2008

Road or Railway construction over soft ground is needed to be considered on secondary consolidation which will be caused differential settlement, lack of transport serviceability, higher maintenance cost. Especially for the railway construction in the second phase of Gyung-Bu or Ho-Nam high speed railway, concrete slab track has been adapted as a safe and cost effective geotechnical solution. In this case controlling the total settlement under the tolerance is essential. And pile supported geogrid reinforced construction method is suggested as a solution for the problem of the traditional method on soft soil treatments. Pile supported geogrid reinforced construction method consists of piles that are designed to transfer the load of the embankment through the compressible soil layer to a firm foundation. The load from the embankment must be effectively transferred to the piles to prevent punching of the piles through the embankment fill creating differential settlement at the surface of the embankment. The arrangement of the piles can create soil arching to carry the load of embankment to the piles. In order to minimize the number of piles geogrid reinforced pile supported construction method is being used on a regular basis. This method consists of one or more layers of geogrid reinforcement placed between the top of the piles and the bottom of the embankment. This paper presents several methods of pile supported geogrid reinforced construction and calculation results from the several methods and comparison of them.

• Journal of Conservation Science
• /
• v.34 no.6
• /
• pp.549-556
• /
• 2018

In November 2011, various artifacts were excavated from the No. 8 stone-lined tomb in Suchon-ri, Gongju by the Chungnam Institute of History and Culture. These included artifacts with lacquered mainframe and silvery metal ornament. These were recovered together with soil and underwent conservation treatment. In this paper, we discuss the scientific analysis and conservation treatment of the lacquered artifacts excavated from the Suchon-ri site. Among our findings is that the artifacts have three layers of lacquer coating and the metal parts are primarily composed of Ag. As the artifacts were recovered with soil from the site, the soil was removed from underneath and inside the artifacts. The inside of the lacquerware was reinforced with rayon paper using 3% funori, and the metal was treated with acrylic resin after removing the acrylic resin previously used to recover the artifact, followed by cleaning. The metal was also internally reinforced with gauze. Finally, the interior reinforcement was made using PVA and resin in pulp and attached with funori to preserve the shape of the lacquerware, and the exposed rayon was finished with acrylic paint. The main advantages of this study are its review of conservation treatment strategies for lacquer artifacts whose numbers have recently increased, and the application of new conservation treatment methods.