• Title/Summary/Keyword: Consolidation effect

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Evaluation of Consolidation Characteristics Considering the Mixed Gradation Ratio of Soft Ground (연약지반의 입도 혼합비를 고려한 압밀특성평가)

  • Park, Yeong-Mog;Yun, Sang-Jong;Chea, Jong-Gil
    • Journal of the Korean Geotechnical Society
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    • v.25 no.10
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    • pp.99-110
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    • 2009
  • In order to provide the design criteria, the characteristics of consolidation for soft ground improvement have been investigated using the field banking test performed by the vertical drain method at the northern container section in Busan New Port. Field test results indicated that the estimated degree of consolidation in design stage decreased by about 7% compared with the measured one. This difference is attributed to the fact that the conservative geological properties were applied with relatively high amount of maximum clay mixture ratio during the design stage. Based on this findings, another laboratory oedometer test was implemented to consider various combination of mixture ratio. It was found that the consolidation degree increased in accordance with the increase of sand/silt mixture ratio. Also, the proportion of 10%, 50%, and 40% for sand, silt, and clay, respectively, was observed as the best combination of mixture ratio to the actual measurement, which is very similar to the average grain size distribution in the banking test area. Therefore, it is suggested that the overall geological characteristics as well as the grain size distribution should be considered in design stage to improve the soft ground that contains mixture of sand, silt, and clay.

Prediction of Compression Index of Busan and Inchon Clays Considering Sedimentation State (부산과 인천점토의 퇴적상태를 고려한 압축지수 추정)

  • Hong, Sung-Jin;Kim, Dong-Hee;Choi, Young-Min;Lee, Woo-Jin
    • Journal of the Korean Geotechnical Society
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    • v.27 no.9
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    • pp.37-46
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    • 2011
  • The compression index, which represents the compressibility of clay, is generally obtained from the consolidation test, or has been predicted by empirical correlations with soil properties. In this study, the results of consolidation tests on natural and reconstituted Busan and Inchon clays are analyzed to figure out the sedimentation state and its effect on empirical correlations. Results of analysis show that the void index of Busan clay is higher than SCL while the void index of Inchon clay is lower than SCL. By comparing prediction errors with ${\Delta}e_r$, which represents the sedimentation state of clay, it is shown that errors predicting the compressibility based on the liquid limit and plasticity index decrease as ${\Delta}e_r$ increases. Supplemented correlations predicting the compression index of Busan and Inchon clays are suggested using these relationships.

A Study on the Anisotropic Characteristics of Permeability of a Remolded Decomposed Mudstone Soil in Pohang (재성형된 포항 이암풍화토의 투수에 관한 이방성 연구)

  • Kim, Young-Su;Jung, Sung-Gwan;Kim, Dae-Man;Kwon, Yong-Min
    • Journal of the Korean GEO-environmental Society
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    • v.4 no.3
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    • pp.5-17
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    • 2003
  • Using Rowe cell for vertical and lateral consolidate test, we concerned characteristics of vertical and lateral consolidation, and permeability on the remolded Decompoed Mudstone Soil in Phoang, and then, compared it with Oedometer test results. Indirect coefficients of permeability were calculated by the results of the coefficient of consolidation that were derived from 9 different kinds of methods. The values of indirect coefficients of permeability derived from ${\sqrt{t}}$ method and hyperbolic method were similar to the results of direct coefficients of permeability with respect to vertical drainage, but, in the case of lateral drainage, for all kinds of methods, the values of indirect coefficients of permeability showed overestimated ones. With vertical and lateral direct coefficient of permeability, by investigating the anisotropic effect with respect to permeability on Decomposed mudstone soil, we obtained average value, 13, with respect to anisotropic characteristics for all kinds of consolidation loadings.

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Variation of Undrained Shear Behavior with Consolidation Stress Ratio of Nakdong River Sand (압밀응력비에 따른 낙동강모래의 비배수전단거통 특성)

  • 김영수;정성관;송준혁;정동길
    • Journal of the Korean Geotechnical Society
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    • v.19 no.4
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    • pp.83-93
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    • 2003
  • This research, in order to study the effects of initial shear stress of anisotropically consolidated sand that has 0.558% fines, performed several undrained static and dynamic triaxial test. To simulate the real field conditions, loose and dense samples were prepared. Besides, the cyclic shear strength of Nakdong River sand under various combinations of initial static shear stress, stress path, pore water pressure and residual strength relationship was studied. By using Bolton's theory, peak internal friction angle at failure which has considerable effects on the relative density and mean effective stress was determined. In p'- q diagram, the phase transformation line moves closer to the failure line as the specimen's initial anistropical consolidation stress increases. Loose sands were more affected than dense sands. The increase of consolidation stress ratio from 1.4 to 1.8 had an effect on liquefaction resistance strength resulting from the increase of relativity density, and showed similar CSR values in dense specimen condition.

Interpreting Characteristics of Educational Facilities Arrangement According to Jinhae's Historical Development Using Space Syntax Theory (진해 교육시설의 시대별 배치 특징에 관한 공간통사론적 해석)

  • Yang, Seung-Jung;Lee, Hyun-Hee;Lee, Jae Hong
    • Journal of the Korean Institute of Educational Facilities
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    • v.22 no.3
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    • pp.21-29
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    • 2015
  • Jinhae's educational facilities had been located in the most integrated area at the beginning. As Jinhae's spatial layout has been in a rapid growth by constructing new towns and experiencing major consolidations over years, it was argued that this morphological transformation inevitably brought to the change of the characteristics of educational facilities' arrangement. In this reason, a number of studies have discussed the ways of how they have been settled down from the beginning of Jinhae. However, they did not take into an account of both the first consolidation happened in 1985 and the second one in 2013. This paper therefore aims to investigate how Jinhae's urban structure has been transformed between the two consolidations from a syntactical perspective, and then to interpret characteristics of educational facilities arrangement accordingly. This study finds out that when Jinhae experienced the first consolidation, educational facilities were occupied in highly segregated areas in terms of both global and local integration values. However, their locations turned out to be more intelligible after the second consolidation. This suggests that they have a significant effect on the process of urban growth at local level. Although the educational facilities particularly in Pungho and Ungchun are in highly integrated spaces at global level, they are still less intelligible.

Thermal Conductivity of Saturated Unfrozen Kaolinite during Consolidation (포화된 카올리나이트의 압밀에 따른 열전도계수에 관한 연구)

  • Kim, Hak-Seung;Lee, Jang-Guen;Kang, Jae-Mo;Kim, Young-Seok;Hong, Seung-Seo
    • The Journal of Engineering Geology
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    • v.21 no.2
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    • pp.157-162
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    • 2011
  • Experimental tests have been performed to measure the thermal conductivity of unsaturated soils, and computational models have been widely used to predict thermal conductivity. However, measured values of the thermal conductivity of unsaturated soils cannot be compared with predicted values because of the gradient in moisture content within unsaturated soils. In this study, experimental consolidation tests on saturated unfrozen kaolinite were performed to investigate the effect of dry density and moisture content on thermal conductivity. The results were used to evaluate the validity of a model employed to calculate thermal conductivity.

Assessment of the Models for Predicting the Thermal Conductivity of Saturated Kaolinite (포화된 카올리나이트를 이용한 열전도계수 예측모델의 신뢰성 검토)

  • Lee, Jangguen;Kim, Hakseung;Kang, Jaemo;Kim, Youngseok;Bae, Gyujin
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.3
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    • pp.21-27
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    • 2012
  • Estimating the thermal conductivity of clayey soils is important for enhancing the performance of geoengineering structures in cold regions and clay barriers for nuclear waste repositories, but specimen disturbance, saturation, and heat boundary conditions of the test apparatus hinder reliable measurements of the thermal conductivity of saturated clayey soils. This paper presents the results of an experimental study carried out using modified consolidation tests with the needle probe method to measure thermal conductivity. Experimental consolidation tests with saturated kaolinite were performed to investigate the effect of effective stress and dry density on thermal conductivity for saturated kaolinite. In addition, thermal conductivity of soil particles were thoroughly investigated and experimental results were used to evaluate the accuracy of the models to predict thermal conductivity.

Effect of Calcium Sulfate and Sodium Hyaluronate on Early Bone Consolidation in Distraction Osteogenesis of the Canine Mandible (개의 하악골에서 신생골 조기 골경화에 Calcium Sulfate와 Sodium Hyaluronate가 미치는 영향)

  • 이주명;조병채
    • Journal of Veterinary Clinics
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    • v.20 no.3
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    • pp.351-356
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    • 2003
  • The aim of this experiment was to study the calcium sulfate on early bone consolidation in distraction osteogenesis in the canine mandible. Twelve dogs were used and divided into control group (group A, 4 heads), sodium hyaluronate injection group (group B, 4 heads), mixture of calcium sulfate and sodium hyaluronate injection group (group C, 4 heads). Each group were subdivided into 3 weeks testing group (totally 6 heads) and 5 weeks testing group (totally 6 heads). Mandibular distraction was started at the 5th day after the mandibular osteotomy and continued for 10 days by 1 mm a day. After the distraction on the 10th day of mandibular distraction, 0.5 m1 saline in group A, 0.5 m1 sodium hyaluronate in group B, and 0.5 ml mixture of calcium sulfate and sodium hyaluronate in group C were each injected in mandibular distraction lesion. And X-ray examination, bone mineral density, and histopathological findings were examined. The radiological findings were the most radiopaque in group C, and the most radiolucent in group A in both 3 and 5 week testing group. The level of bone mineral density was also the highest in group C, and the lowest in group C in both 3 and 5 week testing group. The histopathological findings of new bone formation were the most remarkable in group C in both 3 and 5 week testing group. New bone formation of group A was not present in both 3 and 5 week testing group. In conclusion, calcium sulfate is a kind of material that can stimulate early bone formation and can shorten the duration of bone consolidation. And it can be effective in clinical usage.

Selection and Conservation for the Filler of Three-storied Stone Pagoda at the West of Gameunsaji Site in Gyeongju (경주 감은사지서삼층석탑 충전제 선정과 보존처리)

  • Lee, Tae-Jong;Kim, Sa-Dug;Gal, Seo-Yeon
    • Journal of Conservation Science
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    • v.26 no.4
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    • pp.361-370
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    • 2010
  • The open pore of stone cultural heritage is not expected to have an effect only by consolidation, and it has a drawback that only the internal wall adheres and gets consolidated due to the incrase of liquidity caused by the low viscosity and difference of materials in the case of filling with high molecules synthetic resins. Therefore, this research selected the effective filler for Three-storied Stone Pagoda at the West of Gameunsaji Site through the verification of filling effects of materials using the information about various fillers based on minerals. As the result of filler experiment, got filled with the combination of KSE 500 STE + KSE Filler A${\cdot}$KSE Filler B that is the same as the Member or has very similar properties. The total surface area of the west stone is $252.6m^2$ and the area where the internal opening has been developed is $17.77m^2$(7.03%) requiring a task that fills the internal($24,885m{\ell}$).

Distorted Bounding Surface of Clay with Consideration of the Effect of Temperature on Shearing Response (전단시 온도 영향을 고려한 점성토의 왜곡 경계면 모델 개발)

  • Woo, Sang Inn;Yune, Chan-Young
    • Journal of the Korean Geotechnical Society
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    • v.36 no.12
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    • pp.117-124
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    • 2020
  • The present research focuses on a methodology to describe shearing response of clay with respect to temperature. An increase of temperature shifts the normal consolidation line to move down in the plane of void ratio and mean effective stress. The critical state line, however, does not move as much as the normal consolidation line in accordance with temperature increase. As temperature increase, therefore, the difference between the critical state mean effective stress and the pre-consolidation pressure reduces. To reflect this easily, the present study applies a bounding surface consisting of two parts divided by the critical state mean effective stress. This study calibrated a bounding surface for the soft Bangkok clay and performed elemental simulation for undrained triaxial compression tests. The elemental simulation showed that the model can describe the mechanical response upon temperature of clay without complex hardening and evolution rules compared to the experimental data.