• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.113-113
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• 2010

본 논문에서는 composite hollow bushing에 사용되는 FRP tube의 winding 각도 및 장력 변화에 의한 변위 특성을 해석하였다. Winding 각도 및 장력에 따라 FRP tube의 인장 및 굽힘강도 특성이 변화되므로 최적의 composite bushing의 설계하기 위해서는 이에 대한 해석 및 시험이 요구된다. 따라서, 본 논문에서는 와인딩 각도 및 와인딩 장력에 따른 굽힘강도와 변위에 대하여 고찰하였으며, 와인딩 장력에 따른 각각의 특성에 대해서도 검토하였다.

• Journal of the Korean Geotechnical Society
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• v.20 no.5
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• pp.109-116
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• 2004

The model tests are conducted to assess the behavior characteristics of geogrid reinforced soil walls according to different surcharge pressures and reinforcement spacings. The models are built in the box having dimension, 100cm tall, 140cm long, and 100cm wide. The reinforcement used is geogrid(tensile strength 2.26t/m). Decomposed ganite soil(SM) is used as a backfill material. The strain gauges and LVDTs are Installed to obtain the strain in the reinforcements and the displacements of the wall face. From the results, it can be concluded that the more the reinforcement tensile strength increases, the more the wall displacements and the geogrid strains decreases. The maximum wall displacements and geogrid strains of the model walls occur due to the uniform surcharge pressure at the 0.7H from the bottom of the wall. The horizontal displacements of the wall face nonlinearly increase with the increase of surcharge pressures, and this nonlinear behavior is significantly presented for larger surcharge due to the nonlinear tensile strength-strain relationship of the reinforcements.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.119-127
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• 2017

This paper presents a study of reinforced earth model wall reinforced by geosynthetics subjected to vertical surcharge. 7 types of reinforced earth model wall were constructed in the model box($100cm{\times}140cm{\times}100cm$) to assess the deformation and stress behavior of model walls according to different tensile strength and laying number of reinforcement and surcharge pressures. 3 types of geosynthetics that have different tensile strength were used as reinforcement. The test was carried out by changing the number of reinforcement to 5, 7, 9, and surcharge pressure to 50, 100, 150, 200, 250 kPa. The model test found that the maximum lateral displacements occurred at the 0.7 H (H : Wall height) position from the bottom of the model wall and vertical stress was low in the smaller surcharge pressure and the larger tensile strength of reinforcement.

• Journal of the Korean Geotechnical Society
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• v.20 no.1
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• pp.83-90
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• 2004

Retaining walls with reinforced earth have been constructed around the world. The use of reinforced earth is a recent development in the design and construction of earth-retaining structure. It is believed that reinforced retaining wall has some advantages which make construction quite simple basically. It wilt take short construction time relatively, comparing, fur example with reinforced-concrete retaining wall. In addition, low price and easy construction will be good attractive points in practical point of view. In this study, five field-tests monitoring data for lateral pressures on geogrid-reinforced retaining wall have been compiled and evaluated. Based on field-tests it is found that horizontal displacements of the facing was measured to be about 0.19∼0.76% and that the maximum tensile strains of reinforcement was evaluated to be about 0.66∼1.98%. The maximum tensile strains, measured from each site, do not reach 5% of the practical allowable strain of the geogrid. And also it is found that the lateral pressure distributions of reinforced-earth retaining wall are close to a trapezoid shape like a flexible retaining wall system, instead of a theoretical triangular shape.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.5
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• pp.428-431
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• 2005

In this paper, the displacement and stress of pile foundation constructed in the soft cohesive soils were measured and investigated at each construction phase. The piles belongs to compressive stress then extension due to lateral flow of soft soils. Battered piles showed different stress state according to construction direction. The lateral displacements of piles radically occurred at the embankment phase.

• The Journal of Engineering Geology
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• v.25 no.2
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• pp.237-250
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• 2015

Underground structures such as a tunnel have been considered as safer than structures on the ground during earthquake. However, severe damages of underground structures occurred at subway tunnel during 1995 Kobe Earthquake and such damages are gradually increased. In this study, a dynamic behavior of a cut and cover tunnel surrounded by weathered soils is investigated using Mohr-Coulomb Model. Parametric study was carried out for boundary conditions, tensile strength, and earthquake magnitudes. The results of numerical analyses in terms of ground deformations and stresses acting on the lining were quite dependent on the side boundary condition (free or fix conditions) and tensile strength of surrounding soils. The ground was deformed upward at the end of earthquake when the side boundary condition was fixed, whereas residual deformations were not predicted when it was free. When the tensile strength of a soil was set to the same as its cohesion, residual deformation was less than 1cm, regardless of side boundary conditions or input accelerations. In addition to that, stress conditions at the maximum deformation and end of earthquake were within an allowable range and considered as safe. Proper boundary conditions and material properties such as tensile strength are quite important because they may significantly impact on the results of dynamic analyses.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.3
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• pp.212-219
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• 2015

This study focuses evaluating the efficiency and performance evaluation of composite type sheet-membrane waterproofing method that utilizes a separation behavior inducement system designed to resolve the chronic problems of disintegration and damage of overlap areas of waterproofing layers. As the result of the test, the tensile strength value was at 13.8N/mm and elongation rate at 587% for the separation behavior inducement type specimen, and the compared specimens had 14.2N/mm for tensile strength and 335% for elongation rate. For the separation behavior adhesion method specimen, when tensile stress or displacement occurred, the Zero-Span tension occurrence did not follow, which resulted in that the bottom sheet layer and the top membrane layer did not simultaneously becoming damaged. When undergoing the top and bottom layers were separated through separation behavior due to lack of flexibility, the bottom layer began to damage at the primary stage, and with the allowed boundary the upper membrane layer began to display flexibility and showed continuous displaced resulting in secondary phase damaging.

• Journal of the Korean Geosynthetics Society
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• v.6 no.2
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• pp.21-26
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• 2007

The tensile properties of geogrid are affected by such factors as temperature, specimen length, gauge length, testing speed and measuring equipment. The tensile strength of geogrids can be determined by ASTM 06637 and ISO 10319. The main differences between two testing methods are testing speed and specimen length. This paper presents the results of the wide-width tensile tests for three geogrids according to different specimen length and tension speed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.275-281
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• 2011

When a flat bar type metal specimen for general tension test is subject to incremental uniaxial tension, a narrow plastic shear band, so called luders band, is generated at some instance. This band typically has an angle to the axis of specimen and many early researches have been done to investigate the condition and angle of this localized deformation phenomenon by many researchers. This study follows the procedure of Thomas(1961) under plane stress boundary condition. $J_2$ plasticity theory, balance of linear momentum, and constitutive equations are used to derive the angle of luders band under plain strain boundary condition. The result was confirmed by other angle based on acoustic tensor theory.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.169-174
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• 2009

We conducted structural analysis to investigate disadvantage of wire-mesh arranged at the plane and to develop three-dimensionally bent U-type wire-mesh. In all case that distributed loading at the whole top slab and the half top slab, and the wire mesh was bent $45^{\circ}$, flexura tensile stress was the fewest in both positive moment and negative moment, and the wire mesh was bent $45^{\circ}$ in crossway the shear stresss was the fewest. Therefore, by arranging wire-mesh with $45^{\circ}$ more bent than plane, flexura tensile stress, shear stress, displacement will be reduced and structural function will be improved.