• Title/Summary/Keyword: settlement characteristics

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Analysis of Settlement Characteristics of Shallow Foundation on Sandy Soil Overlained by Rigid Ground (강성지반위 사질토층에 위치한 얕은기초의 침하량특성분석)

  • Hwang, Hui-Seok;Kim, Dong-Geon;Yoo, Nam-Jae
    • Journal of Industrial Technology
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    • v.34
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    • pp.45-52
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    • 2014
  • In this paper the settlement characteristic of shallow foundation on sandy soil overlained by rigid ground was investigated by analyzing results of model tests. For model experiments, model tests were performed with sandy soils sampled from the field, changing the relative density of sandy soil and the ratio of thickness of sandy layer(H) to the width of model strip footing(B). As result of tests, settlement of sandy soils increases as the value of H/B increases, whereas it increases with relative density of soil. Bearing capacity decreases as the thickness of the sand layer relative to the footing width increases. In order to analyze the settlement characteristics of sandy ground, the results of model tests were compared with the predicted values using the empirical formulas proposed by Terzaghi, De Beer and Schmertmann. The method by De Beer was found to be in good agreements with test results.

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A Study of Bearing Capacity and Settlement of Shallow Foundation by FEM (유한요소법에 의한 얕은 기초의 지지력 및 침하 특성 연구)

  • Park, Jong-Su;Park, Choon-Sik;Jang, Jeong-Wook
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1312-1319
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    • 2006
  • This thesis studied the scale effects on bearing capacity and settlement characteristics by using FEM. The conclusions of the study are as follows. 1) For sandy soil, the bearing capacity ratio increased in the form of logarithm as the foundation width increased. Hence application of static mechanic theory results in overestimation of the bearing capacity when the bearing capacity should be derived from plate loading test results. 2) In clayey soil, the characteristics of the bearing capacity associated with foundation width met Terzaghi's bearing capacity theory. 3) In sandy soil, the settlement ratio increased non-linearly as foundation width increased. However, in clayey soil, the settlement ratio increased linearly. 4) In ordinary soil, the foundation width - settlement ratio turned out to be close to that of sandy soil.

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A study on the characteristics of primary and secondary settlement for a peat soil in Sri-Lanka (Sri-Lanka내 Peat Soil의 일차압밀 및 이차압축 침하특성에 관한 연구)

  • Jin, Sung-Ki;Lee, Jae-Weon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.235-242
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    • 2004
  • For this study, a Peliyagoda area located on a route was selected among many sections of a CKE(Colombo to Katunayake Expressway) route in Sri-Lanka. Its subground consists of a very weak and thick peat soil named amorphous or fibrous peat. All of data, obtained in the design process of soft ground treatment were analyzed to evaluate the settlement characteristics resulted from an embankment load and to present reasonable methods for estimation of secondary compression settlement. For these purposes, soil parameters were used obtainedby field and laboratory tests the settlement analyses were conducted base on the field monitoring results within 20 months. In addition, Reasonable methods were studied to estimate primary consolidation and secondary compression settlement.

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Determinants of Demand for Residential Settlement in Rural Society Based on Depopulation Classification (과소화유형에 따른 농촌사회 정주수요 분석)

  • Lee, Hee-Chan;Kim, Hyun
    • Journal of Korean Society of Rural Planning
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    • v.15 no.1
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    • pp.61-71
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    • 2009
  • The objective of this research was to analyze the determinants of demand for residential settlements in rural societies. A significant aspect of the demand analysis was to consider depopulation classification as a moderating variable with a view to its role as an essential dividing factor of socioeconomic characteristics and physical environments of the areas of concern. The data collection for analysis was divided according to types of depopulation into the three categories of less developed, stagnated, and developed areas. For the cause and effect analysis between the residential demand and factors of settlement, the ordered probit model was applied. Significant determinants of settlement demand unfolded according to depopulation types. In the case of less developed areas, residential demand was affected significantly by the factors of daily life convenience and public facilities. Key settlement demand determinants of stagnated regions included the aspects of basic natural environment, daily life convenience and education. Meanwhile, key settlement demand determinants for developed areas included education and agriculture economic aspects. The importance-performance analysis was also applied to a set of settlement characteristics of rural communities to figure out the settlement factors requiring urgent endeavor to improve.

Field test of the long-term settlement for the post-grouted pile in the deep-thick soft soil

  • Zou, Jin-Feng;Yang, Tao;Deng, Dong-ping
    • Geomechanics and Engineering
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    • v.19 no.2
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    • pp.115-126
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    • 2019
  • The long-term settlement characteristics for the cast-in-place bored pile in the deep-thick soft soil are investigated by post-grouting field tests. Six cast-in-place bored engineering piles and three cast-in-place bored test piles are installed to study the long-term settlement characteristics. Three post-grouting methods (i.e., post-tip-grouting, post-side-grouting, and tip and side post-grouting) are designed and carried out by field tests. Results of the local test show that decreased settlements for the post-side-grouted pile, the post-tip-grouted pile and the tip and side post-grouted pile are 22.2%~25.8%, 30.10%~35.98% and 32.40%~35.50%, respectively, compared with non-grouted piles. The side friction resistance for non-grouted piles, post-side-grouted pile, post-tip-grouted pile and the tip and side post-grouted pile undertakes 89.6~91.3%, 94.6%, 92.4%~93.0%, 95.7% of the total loading, respectively. At last, the parameters back analysis method and numerical calculation are adopted to predict the long-term settlement characteristics of the cast-in-place bored pile in the deep-thick soft soil. Determined Bulk modulus (K) and a creep parameter (Ks) are used for the back analysis of the long-term settlement of the post-grouted pile. The settlement difference between the back analysis and the measurement data is about 1.11%-7.41%. Long-term settlement of the post-grouted piles are predicted by the back analysis method, and the predicted results show that the settlement of the post-grouted pile are less than 6 mm and will be stable in 30 days.

Instrumentation Management of Differential Settlement of the Deep Soft Ground with Dredged Clay Reclaimed in the Upper (대심도 준설 매립지반에서의 층별침하 계측관리에 관한 사례 연구)

  • Tae-Hyung Kim;Seung-Chan Kang;Ji-Gun Chang;Soung-Hun Heo
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.1
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    • pp.87-96
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    • 2023
  • There are a lot of difference between the surface settlement and the differential settlement measured at the Busan New Port, where the dredged and reclaimed clay layer exists and below the clay is originally thickly distributed. To find the cause and solution of this, the actual conditions of each differential settlement used for the soft ground improvement, characteristics, installation method, measurement frequency, measurement data management, and data analysis of each type were considered. In the deep soft ground improvement work where large deformation occurs, the bending deformation of the screw-type differential settlement gauge is less than that of other types of measuring instruments, so there is less risk of loss, and the reliability of data is relatively high as the instruments are installed by drilling for each stratum. Since the greater the amount of high-precision settlement measurement data, the higher the settlement analysis precision. It is necessary to manage with higher criteria than the measurement frequency suggested in the standard specification. For the data management of the differential settlement gauge, it is desirable to create graphs of the settlement and embankment height of the relevant section over time, such as surface, differential, and settlement of pore water pressure gauge for each point. In the case of multi-layered ground with different compression characteristics, it is more appropriate to perform settlement analysis by calculating the consolidation characteristics of each stratum using a differential settlement data.

Soft Ground Settlement Estimation Using Neural Network (인공신경망을 이용한 연약지반 침하량 산정)

  • Roh, Jae-Ho;Won, Hyeo-Jea;Oh, Doo-Hwan;Hwang, Sun-Geun
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1405-1410
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    • 2006
  • Purpose of this research is that offers basic data for optimized design using neural network method to calculate consolidation settlement in study area. In this research, preformed the neural network method that analyzed the settlement characteristics of soft ground nearby study area. Thus, data base established on ground properties and consolidation settlement of neighboring area. In addition, designed the optimum neural network model for prediction of settlement through network learning and consolidation settlement prediction using consolidation settlement DB and ground properties DB. Optimized neural network model decided by repeated learning for various case of hidden layers. In this study, proposed that the optimized consolidation settlement calculation method using neural network and verified which is the optimized consolidation settlement calculation method using neural network.

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Prediction and Measurement of Behaviour of Soft Soil Deposits (연약지반에서 예측 거동과 계측 결과 분석)

  • Kim, Yun-Tae
    • Proceedings of the Korean Geotechical Society Conference
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    • 2007.09a
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    • pp.351-362
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    • 2007
  • Predicted behaviour of a soft clay deposit in design stage is sometimes different from in-situ settlement and pore pressure measured during and after construction. In this paper, characteristics of settlement and pore pressure occurred in soft soil deposits were investigated briefly in order to get a better understanding of time-dependent viscoplastic behaviour and prevent geotechnical problems resulted from long-term settlement, differential settlement, etc.

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Modeling Demand for Rural Settlement of Urban Residents (도시민의 농촌이주 수요모형 분석: 정착자금 지원효과를 중심으로)

  • Lee, Hee-Chan
    • Journal of Korean Society of Rural Planning
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    • v.15 no.2
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    • pp.97-110
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    • 2009
  • The objective of this research was to develop a rural settlement demand model to analyze the determinants of settlement demand of urban residents. The point aimed at from model development was deriving stated preference of potential consumers towards rural settlement through setting a hypothetical market, and using settlement subsidy as a surrogate variable for price in the demand model. The adequate demand model deducted from hypothetical market data was derived from the basis of Hanemann's utility difference theory. In the rural settlement demand model, willingness to accept was expressed by a function of settlement subsidy. Data utilized in the analysis was collected from surveys of households nationwide. According to inferred results of the demand model, settlement subsidy had a significant influence on increasing demand for rural settlement. A significant common element was found among variables affecting demand increase through demand curve shift. The majority group of those with high rural settlement demand sought agricultural activity as their main motive, due to harsh urban environments aggravated by unstable job market conditions. Subsequently, restriction of income opportunities in rural areas does not produce an entrance barrier for potential rural settlers. Moreover, this argument could be supported by the common trend of those with high rural settlement demand generally tending to have low incomes. Due to such characteristics of concerned groups of rural settlement demand, they tended to react susceptibly to the subsidy provided by the government and local autonomous entities.

An Experimental Study of Settlement Behavior of Artificial Reef according to Reinforcement Characteristics (해저 연약지반 보강 조건에 따른 인공어초 침하 거동에 대한 실험적 연구)

  • Yun, Dae-Ho;Kim, Yun-Tae
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.1
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    • pp.53-61
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    • 2017
  • Seabed settlement and erosion sometimes occurr when a artificial reef is installed in soft seabed. Therefore, this study carried out CBR test and water tank settlement test to investigate settlement behavior of artificial reef according to reinforcement characteristics such as reinforced types and reinforced area. Soil types of ground are sand, silt and clay deposits. Three reinforced types were prepared: unreinforced, geogrid and hybrid bamboo mat(HBM) with different reinforced area. Laboratory test results indicated that reinforced artificial reef improved bearing capacity of ground and reduced settlement as reinforced area increased. Especially, reinforced HBM provided more bearing capacity and less settlement than reinforced geogrid.