• Title/Summary/Keyword: consolidation property

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Finite Element Analysis for the Effects on the Stiffness of the Embankment and Sandmat on the Deformation Property and the Safety of Road Embankment (성토체 및 모래매트의 강성이 하부지반의 변형과 성토체의 안전에 미치는 영향에 대한 유한요소해석)

  • Bae, Woo-Seok;Kim, Jong-Woo;Kwon, Young-Cheul
    • Journal of the Korean Society of Safety
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    • v.22 no.4
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    • pp.57-65
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    • 2007
  • Effects on the stiffness of the embankment and sandmat on the construction safety of road embankment was investigated in this study by the numerical experiments using FEM. Two points was mainly focused in this study especially. First the deformation characteristics by the change of the stiffness of sand mat and embankment was investigated by the analyzing the consolidation settlement at the center of the embankment and the lateral displacement at the toe of the embankment. And, the effect of the stiffness on the stress distribution characteristics was also investigated in this study. Furthermore, slope stability analysis was carried out to gain the safe factor by change the stiffness of the sandmat and the embankment. The objective of the study is supplying the result of the numerical experiments for the geotechnical engineers who use the FEM for the safety design of the soil structures. As a result, the stiffness of the superstructures greatly affects on the deformation characteristics both in consolidation settlement and lateral displacement. However, it can be aware that it is not dominants to the stress distribution in the aspect that the no changes in the residual excess pore water pressure. Therefore, the decision of the stiffness has to be carried out deliberately considering not only the consolidation the magnitude of the settlement and the lateral displacement, but the slope stability.

Retention Ratio of Dredged Soil at Incheon Habour Route using Self-Weight Consolidation Test (인천지역 항로 준설토의 침강자중압밀시험에 의한 유보율 결정에 관한 연구)

  • Shin, Eun-Chul;Park, Young-Jin;Kang, Jeong-Ku
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.4
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    • pp.57-66
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    • 2017
  • Self-weight consolidation test and soil property of dredged soil at Incheon habour route were analyzed to determine the initial dredging reclamation amount, reclamation depth, and estimating the required time of self-weight consolidation with calculation of the final planned height of dredging reclamation site. The moisture content, void ratio and ratio of volume change with elapsed time after throwing were estimated through Yano's empirical equation. As a result, there was a less variation in elements when fine-grained soil content was low as similarly to the behavior of coefficient of sedimentation-consolidation, Cs and the highest variation was shown at the fine-grained soil content of 50%. The retention ratio according to the fine grained soil content that could reinforce the comprehensive aspect of retention ratio for each particle size presented in the standard of estimate for reclamation construction work was calculated and presented using the calculated ratio of volume change.

Questions and Solutions on Repair of Lime-Soil Consolidation in Traditional Buildings (전통 건축물 석회다짐층 보수 시공시의 문제점 및 개선 방안)

  • Kim, Jin-Man;Kwak, Eun-Gu;Suh, Man-Cheol;Cho, Heon-Young
    • 한국문화재보존과학회:학술대회논문집
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    • 2002.02a
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    • pp.21-31
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    • 2002
  • Lime-soil consolidations are very important as structural material, bonding material, waterproofing material, and finishing material in korea traditional buildings. In this study, we investigated site application trouble in korea traditional buildings being repaired or restored, and propose following solutions. 1) To diminish quality variation occurred by slaking quick-lime in site, it is desirable to use slaked-lime for lime-soil consolidation. 2) For uniform construction of lime-soil consolidation, we would recommend builders to use mixer to be uniform mixture, premixed type materials and compacting machine in field, 3) and to use rigid suitable temporary construction as scaffold for preventing traditional buildings from additional damage occurred in demolition and construction of a layer of lime-soil consolidation of a roofing. 4) For suitable repair of traditional buildings, it is necessary to specify definitely materials and construction methods suggested by the standard specifications for repair of the cultural property.

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Development of a Single Allocation Hub Network Design Model with Transportation Economies of Scale (수송 규모의 경제 효과를 고려한 단일 할당 허브 네트워크 설계 모형의 개발)

  • Kim, Dong Kyu;Park, Chang Ho;Lee, Jin Su
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.6D
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    • pp.917-926
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    • 2006
  • Transportation Economies of scale are the essential properties of hub networks. One critical property of the hub network design problem is to quantify cost savings which stem from economies of scale, the costs of operating hub facilities and opportunity costs associated with delays stemming from consolidation of traffic flows. Due to the NP-complete property of the hub location problem, however, most previous researchers have focused on the development of heuristic algorithms for approximate solutions. The purpose of this paper is to develop a hub network design model considering transportation economies of scale from the consolidation of traffic flows. The model is designed to consider the uniqueness of hub networks and to determine several cost components. The heuristic algorithms for the developed model are suggested and the results of the model are compared with recently published studies using real data. Results of the analysis show that the proposed model reflects transportation economies of scale due to consolidation of flows. This study can form not only the theoretical basis of an effective and rational hub network design but contribute to the assessment of existing and planned logistics systems.

Microstructure and Mechanical Property of Aluminum Powder Compact by Powder-in Sheath Rolling Method (분말시스압연법에 의해 제조된 알루미늄 분말성형체의 조직 및 기계적 성질)

  • 이성희
    • Journal of Powder Materials
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    • v.9 no.3
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    • pp.153-160
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    • 2002
  • A nitrogen gas atomized aluminum powder was consolidated by powder-in sheath rolling method. A pure aluminum tube with outer diameter of 12 mm and wall thickness of 1mm was used as a sheath. The aluminum tube filled with the aluminum powder, first, was cold-rolled to the thickness of 6mm for performing, and then consolidated by the cold rolling and/or subsequent hot rolling at 360, 460 and $560^{\circ}C$. The aluminum powder compact fabricated by the sheath rolling showed high relative density more than 0.96 at any rolling conditions. The 0.2% proof stress increased with increasing hot rolling reduction and hot rolling temperature. Tensile strength was hardly affected by change in the hot rolling reduction, whereas it decreased with increasing hot rolling temperature. The powder compact showed the large elongation when cold rolling or hot rolling reduction was large. It was found that the sheath rolling was an effective method for consolidation of aluminum powder.

A Study on Characteristics of Strength Increase and Bearing Capacity in Dredged and Reclaimed Soil due to Desiccation Shrinkage (준설토의 건조수축에 의한 강도증가 특성과 지지력에 관한 연구)

  • Yoo, Nam-Jae;Lee, Jong-Ho;Lee, Myung-Woog;Kim, Hyun-Joo
    • Journal of Industrial Technology
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    • v.20 no.A
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    • pp.101-111
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    • 2000
  • This research is results of experimental and numerical works on characteristic of strength increase and bearing capacity in dredged and reclaimed soil due to desiccation shrinkage. For a soil sampled from southern coastal area in Korea, basic soil property tests and standard consolidation test with falling head permeability tests were carried out to obtain consolidational characteristics of soil. Double cone penetration test, laboratory vane test and unconfined compression test were also performed to investigate the change of shear strength with degree of desiccation. Model tests were performed in 1G environment and 30G level artificially accelerated condition by using the centrifuge model test facilities to investigate the bearing capacity of desiccated ground. Test results were analyzed by using the theoretical and load-settlement characteristics method proposed by Meyehof & Hanna(1978). On the other hands, the numerical technique, using the finite strain consolidation theory considering the effect of desiccation was used to estimate the appropriate time of using heavy construction equipments in field with respect to strength increase due to desiccation.

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Erosion Characteristics of Kaolinite (카올리나이트의 침식특성)

  • Lee, Ju-Hyung;Kwak, Ki-Seok;Park, Jae-Hyeon;Chung, Moon-Kyung
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.533-537
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    • 2004
  • The erodibility of soil is an important factor to scour, especially in fine-grained soils. In this study, the erosion characteristics of kaolinite are quantified through the scour rate tests using the Erosion Function Apparatus called EFA. The basic soil property tests are also performed. The kaolinite samples are prepared by mixing with distilled water and formed to the designed maximum consolidation pressure of 60, 110, 160, 240, 360kPa, respectively. The results of the scour rate tests are presented in a format of a plot showing the relationship between erosion rates and shear stresses. Erosion properties of kaolinite showed a striking contrast according to the maximum consolidation pressure, and a correlation was established between the erosion properties of kaolinite and the soil properties; water content, undrained shear strength, dry density.

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A comparative study on consolidants for bronze objects conservation (청동유물 보존처리에 사용되는 강화처리제의 특성 비교)

  • Cho, Hyun-Kyung;Cho, Nam-Chul
    • Analytical Science and Technology
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    • v.22 no.3
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    • pp.263-271
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    • 2009
  • The purpose of metal artifacts conservation is recovering the original state of objects and preventing it from further corrosion. Four different consolidants are selected that are widely used for bronze objects conservation. This study found out the characteristics of thin film by various experiments and analysis for the bronze plates coated using each solutions. After a series of analysis, resin B and V showed good coating properties. However, the evaluation point suited to this purpose are adhesive strength, stability against yellowing and corrosion resistance. Therefore, resin B of four different consolidants could expect to get the most suitable consolidation effect for consolidation purpose.

The Effective $P_2O_5$ Doping into $B_2O_3-P_2O_5-SiO_2$ Silica Layer Fabrication by Flame Hydrolysis Deposition (FHD법에 의한 $B_2O_3-P_2O_5-SiO_2$ 실리카막의 효과적인 $P_2O_5$ 도핑)

  • 심재기;이윤학;성희경;최태구
    • Journal of the Korean Ceramic Society
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    • v.35 no.4
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    • pp.364-370
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    • 1998
  • Boron-phoshor-silicate glass was fabricated on Si substrates by FHD(Flame Hydrolysis Deposition) The microstructrue of silica soot deposited at various conditon such as composition and substrate temperature was analysed by SEM. After consolidation the refractive index and composition of the silica layer were in-vestigated. For refractive index control B, P and Ge were used as additive elements while B and Ge oxides are easily mixed into $SiO_2$, P oxide($B_2O_3$) doping is difficult because of the volatile property due to low melt-ing point. Boron-phosphorous-silicate glass (BPSG) layer were fabricated using bertical torch and optimized flame temperature substrate temperature and distance of torch and substrate. P concentration of BPSG lay-er measured 3.3 Wt% and the consolidation temperature was lower than $1180^{\circ}C$. The measured refractive index of BPSG silica layer in $1.55\;\mu\textrm{m}$ wavelength was $1.4480{\pm}1{\times}10^{-1}$ and the thickness was $22{\pm}1\;\mu\textrm{m}$.

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A Study on the Engineering Properties of Alluvial Clays (충적점토의 토질공학적 제성상에 관한 연구)

  • 류기송;김시원
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.20 no.4
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    • pp.4805-4811
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    • 1978
  • This paper deals with the correlations between the results of the physical property tests and the mechanical property tests for estimating the mechanical indexes by the physical property test results. The soil samples were taken at changweon area, Gyeon-gsangnam-do, where the structures would be placed on the alluvial clay foundation. The outcomes of the study are as follows: 1. Judging from casagrande's plasticity chart, it is considered that the almost all soil samples belong to inorganic silty clay with medium plasticity (clay 14∼62%, silt 36∼73%, sand 1∼29%). The specific gravities are between 2.61 and 2.72, the wet unit weights 1.53g/㎤ and 1.93g/㎤, the liquid limits 28% and 51%, the plastic limits 15% and 31%, the plastic indexes 7% and 27%, the natural moisture contents 33% and 64%. 2. The unconfined compression strengths are between 0.07kg/$\textrm{cm}^2$ and 0.77kg/$\textrm{cm}^2$, the cohesions 0.04kg/$\textrm{cm}^2$ and 0.37kg/$\textrm{cm}^2$, the internal friction angles 0$^{\circ}$ and 9$^{\circ}$. 3. The consolidation tests show that the initial void ratios are between 0.68 and 1.68, the precompression loads 0.27kg/$\textrm{cm}^2$ and 1.15kg/$\textrm{cm}^2$, the compression indexes 0.12 and 0.59. 4. The correlations between the results of the physical property tests and the mechanical property tests for the soil samples are presented as follows: rt=0.011 (203-wn), Cc=0.025 (LL-27.2), Cc=0.46 (e0-0.58), Cc=0.013 (wn-23.2), C=0.021+qu/2.08, qu=2.268rt-3.635

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