• 제목/요약/키워드: Settlement estimation

검색결과 212건 처리시간 0.025초

현장계획에 의한 연약지반의 장기 침하 예측지법에 관한 실증적 연구 (A Study on the Practical Estimation Technique of a Long-term Settlement by the Observation Results in the Field)

  • 서수봉;김수삼
    • 한국해양공학회지
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    • 제5권1호
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    • pp.35-44
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    • 1991
  • This study was carried out for the purpose of pre-estimating long-term settlement under condition of actual field soil's property, in case of building up industrial sites on the marine deposit silty clay located at West Coast in Korea. This study analyzed Hyperbolic Method, Square Root Time Method and Exponential Function Method with utilization of measured survey values of settlement in In-Cheon Namdong Industrial Sites. In the future, for the continuos utilization, it seemed to be needed that further the survey values of fields should be accurartely measured for the analysis of more accurate pre-estimate about long-term settlement. Among the prediction methods of settlement Hyperbolic Method seemed to be the best fitting method for measured data. The settlement equations were derived from above three methods, for long-term settlements.

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점토(粘土) 지반상(地盤上)의 성토(盛土)의 압밀침하(壓密沈下) 분석(分析) (Analysis for Consolidation-Settlement of Embankment on Clay Layers)

  • 정성관;권무남
    • Current Research on Agriculture and Life Sciences
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    • 제2권
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    • pp.98-108
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    • 1984
  • Generally, in case of constructing the embankments on the soft clay layers, one-dimensional consolidation settlement under the assumption of a middle position stress in a single layer makes a great difference with the integral value, ie. the final settlement. Consequently, to find how many equal segments of the soft clay layer are needed to converge into the integral value and which position should be taken as a position of mean stress, authors compared the theoretical value of the settlement due to one-dimensional consolidation with the practical value of the settlement due to two dimensional consolidation. The obtained results are as follows. 1) The practical value of the two-dimensional consolidation settlement can be estimated by the 74-83% theoretical value of the one-dimensional consolidation settlement. 2) When the soft clay layer was cut into 8-16 equal segments according to the depth, one-dimensional consolidation settlement converge into the integral value. 3) Assuming a total soft clay layer as a single one, the depth of a mean stress position is 0.29-0.37 of the thickness of the total soft clay layer. 4) The Hyperbola Method which presumes the long-term settlement from the short-term practical value of settlement is credible, because all practical value of the settlement are in safe side of the standard error of estimation and the correlation coefficient is up to 0.95.

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천층터널 쉴드TBM에서 역해석을 이용한 Gap Parameter 및 지표침하 영향범위에 대한 연구 (A study on Gap Parameter and Influence Area of Ground Settlement Using Back Analysis Constructed by Shield TBM with Shallow Depth)

  • 고성일;권성주;황창희;김상인;추석연
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.1509-1518
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    • 2011
  • Shield TBM tunneling method has been getting the spotlight for urban tunneling. It can be minimized the civil complaint during construction and possible safe tunneling. But the settlement has occurred inevitably due to characteristics of shield TBM equipment. For this reason, the civil complaint can occur in urban areas when tunnel with shallow depth passes through neighboring building or residential area. In this study, the occurrence factors of settlement according to shield TBM tunneling and the tendency of ground settlement by strata condition had analyzed. It is suggested that the practical settlement estimation method and minimizing method of ground settlement under simultaneous backfill grouting condition through measurement results and back analysis data using gap parameter.

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계곡형상을 고려한 CFRD의 축조 중 침하량 예측 (Settlement Estimation of CFRD Considering Valley Shape During Construction Period)

  • 박한규;김용성;임희대
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 지반공학 공동 학술발표회
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    • pp.302-305
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    • 2005
  • In this study, settlement characteristics of 38 CFRD was investigated from monitoring data and the method to estimate the dam settlements considering valley shape during constructions was proposed. The construction modulus of dam was found to be dependent on void ratios and valley shape factor. The construction modulus varied with valley shape and decreased with increasing void ratio. Also, the modulus was increased when the shape coefficient was less than 4. The settlement investigation results showed that the total settlement was proportional to the value of the settlement coefficient multiplied by the shape coefficient divided by void ratio.

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

  • 진성기;이재원
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2004년도 춘계학술발표회
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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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압축지수의 추정방법이 압밀침하량의 공간적 분포특성에 미치는 영향 (Influence of Estimation Method of Compression Index on Spatial Distribution of Consolidation Settlement)

  • 김동휘;류동우;김민태;이우진
    • 한국지반공학회논문집
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    • 제26권10호
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    • pp.39-47
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    • 2010
  • 본 논문에서는 분석영역 내 압축지수 분포특성이 압밀침하량의 공간적 분포에 미치는 영향을 알아보기 위해, 압축지수의 분포특성을 고려한 압밀침하 추정방법을 제시하고 추정방법에 따른 압밀침하량 추정 결과를 비교해 보았다. 지반이 불균질한 경우에는 간극비를 이차변수로 이용한 정규공동크리깅이 신뢰할 수 있는 앙축지수 추정결과를 제공하는 것으로 관찰되었으며 이는 감소된 smoothing effect로 인한 것이다. 압축지수와 간극비의 공간적 분포를 고려하는 경우(Case-l)와 모든 지반물성치의 평균값을 쓰는 경우(Case-2) 두 방법은 압밀침하량의 공간적 분포를 상당히 다르게 평가하며, Case-1이 Case-2에 비해 거리에 따른 압밀침하량의 변화가 상대적으로 큰 것으로 나타났다. Case-1의 경우 압밀침하의 공간적 분포는 압밀층 두께뿐만 아니라 압축지수의 분포에도 영향을 받는 반면 Case-2의 경우 압밀층의 두께 분포에 가장 큰 영향을 받는 것으로 나타났다.

화강풍화토의 변형계수와 상대침하 관계식에 관한 실험적 연구 (An Experimental Study on the Relationship between Deformation and Relative Settlement for Weathered-granite)

  • 박용부
    • 토지주택연구
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    • 제4권1호
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    • pp.125-131
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    • 2013
  • 얕은 기초 설계와 시공을 위해 실시하는 평판재하시험 결과로부터 실제 기초지반의 침하량을 산정하고 있는데 국내에서 많이 시공되는 화강풍화토나 풍화암에 대한 현장 예측식이 없는 실정이다. 따라서, 본 연구에서는 화강풍화토와 풍화암을 대상으로 현장 평판 재하시험을 실시하여 기초 크기별 침하량 거동을 분석하였다. 모형토조와 현장 재하시험에서 측정한 하중 ~ 침하 곡선을 일반적인 항복하중 판정법을 사용하지 않고 하중 ~ 상대침하(s/B, s : 침하량, B : 재하판폭) 관계로 정규화(Normalization)하여 분석하였다. 즉, 하중 ~ 상대 침하 개념으로 정규화한 결과, 재하판 직경에 관계없이 일정한 형태의 곡선을 나타내므로 현장의 지반조건과 상관성을 제시하였다.

조립토 다짐말뚝의 침하량 산정기법 (A Estimation Method of Settlement for Granular Compaction Pile)

  • 김홍택;황정순;박준용;윤창진
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.286-293
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    • 2005
  • In soft ground the settlement criterion usually governs. Therefore, it is very important not only reasonable assessment of the allowable bearing capacity of the soil but also reasonable assessment of settlement. In the previous studies by many other researchers, load concentration ratio and settlement reduction factor are usually proposed for estimating the settlement of granular compaction piles. In the previous studies, the reinforced ground with granular compaction piles is simplified as composite ground and the analysis is performed with in the basis of this assumption. However, the lateral deformation of granular compaction pile could not be considered and only the relative vertical strength between pile and soils could be considered in the analysis. In this study, a method adapting the Tresca failure criterion is proposed for calculating settlement of granular compaction pile. Proposed method can be considered the strength of pile material, pile diameter, installing distance of pile and the deformation behavior of vertical and horizontal directions of pile. In the presented study, large-scale field load test is performed and the results are described. Also, predictions of settlements from the proposed method are compared with the results of the load test. In addition, a series of parametric study is performed and the design parameters are analyzed.

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Generalized Schmertmann Equation for settlement estimation of shallow footings in saturated and unsaturated sands

  • Mohamed, Fathi M.O.;Vanapalli, Sai K.;Saatcioglu, Murat
    • Geomechanics and Engineering
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    • 제5권4호
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    • pp.343-362
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    • 2013
  • Simple relationships are proposed in this paper by modifying the Schmertmann's equation for settlement estimations of footings (i.e., $B/L{\approx}1$) carrying vertical loads in saturated and unsaturated sandy soils. The modified method is developed using model plate load tests (PLTs) and cone penetration tests (CPTs) results conducted in saturated and unsaturated sand in a controlled laboratory environment. Seven in-situ large-scale footings tested under both saturated and unsaturated conditions in sands were used to validate the proposed technique. The results of the study are encouraging as they provide reliable estimates of the settlement of shallow footings in both saturated and unsaturated sands using the conventional CPT results.

말뚝의 정재하시험을 통한 현장시험 결과 분석 (A Comparative Study on Field Tests for Driven Pile in Static Load Tests)

  • 천병식;윤환호;윤병태;김영훈
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.1117-1124
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    • 2008
  • In This paper, load-settlement curves that obtained from 11 sites were analyzed. At all tests, the load is applied until apparent failure is observed. The validity of the ultimate and yield load estimation method and load calculated from the settlement criterion was investigated through comparison with the measured data. The result indicated that B. Hansen 80% criterion and Stability Plot in ultimate loading decision law almost have been regared as same by comparing measured date and ultimate bearing capacity decided in depending yield loading decision law from 13% to 46% difference have taeyaeen came out when measured data and Davisson was compared, and S-log t from 5% to 41% log P-log S from 14% to 50% difference have been came out. When Settlement standard and measured data was compared difference had been came out about 3% in total settlement 0.1D criterion and from 12% to 35% difference had been came out in net settlement.

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