• Title/Summary/Keyword: Terzaghi

검색결과 138건 처리시간 0.019초

Calculation and field measurement of earth pressure in shield tunnels under the action of composite foundation

  • Chi Zhang;Shi-ju Ma;Yuan-cheng Guo;Ming-yu Li;Babak Safaei
    • Geomechanics and Engineering
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    • 제34권1호
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    • pp.17-27
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    • 2023
  • Taking a subway shield tunnel in a certain section of Zhengzhou Metro Line 5 as an example, the field tests of shield cutting cement-soil monopile composite foundation were carried out. The load and internal force of the tunnel lining under the action of composite foundation were tested on-site and the distribution characteristics and variation laws of earth pressure around the tunnel under the load holding state of the composite foundation were analyzed. Five different load combinations (i.e., overburden load theory + q0, Terzaghi's theory + q0, Bierbaumer's theory + q0, Xie's theory + q0, and the proposed method (the combination of compound weight method and Terzaghi's theory) + q0) were used to calculate the internal force of the tunnel structure and the obtained results were compared with the measured internal force results. The action mode of earth pressure on the tunnel lining structure was evaluated. Research results show that the earth pressure obtained by the calculation method proposed in this paper was more consistent with the measured value and the deviation between the two was within 5%. The distribution of the calculated internal force of the tunnel structure was more in line with the distribution law of field test data and the deviation between the calculated and measured values was small. This effectively verified the rationality and applicability of the proposed calculation method. Research results provided references for the design and evaluation of shield tunnels under the action of composite foundations.

국내 지반조건을 고려한 흙막이 백제에 작용하는 토압 (The Lateral Earth Pressure on Braced Cut Walls Considering Subsoil Condition in Korea)

  • 채영수;문일
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1994년도 가을 학술발표회 논문집
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    • pp.129-138
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    • 1994
  • It is well recognized that accurate analysis of lateral earth pressure is very signficant factor which determines the design amount of braced cut walls and braced systems. Many researchers, Peck, Terzaghi-Peck and so on, make a study about lateral earth pressure to act on the flexible walls. But these studies trouble accurate to multy layered systems like inland areas in Korea. This study is compared with the field messurement data to estimate the earth pressure distributions in multy layered areas and the empirical earth pressure distributions. The conclusions are as follows : At final excavation depth, the lateral earth pressure which messured by field instrument is smaller than the empirical earth pressure. (About 1.85~5.32 times). In the case of considering the soft rock layer to the final excavation depth, the messured earth pressure is safe to be compared with empirical earth pressure. The messured earth pressure distributions are like that the upper soil layer is small the middle soil layer is large, the rock mass layer is very small.

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함수량이 다른 오염지반의 지지력 결정에 관한 연구 (A Study on the Conclusion Bearing Capacity ol Polluted Soils Owing to Difference of Water Content)

  • 안종필;박상범;박경호
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1999년도 봄 학술발표회 논문집
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    • pp.481-488
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    • 1999
  • This study, investigates the existing theoretical backgrounds in order to examine the behavior of lateral flow owing to the plasticity of soils when unsymmetrical surcharge is worked on polluted soils by the increase of water content compares and analyzes the results measured through model tests. Unsymmetrical surcharge is increased at regular intervals to soil tank made up the polluted soils and then the amounts of settlement, lateral displacement and upheaval are observed. Critical surcharge was decided q$\sub$cr/= 3.42 C$\sub$u/ similar to those had proposed Terzaghi and JHI, and the value of ultimate capacity was decided q$\sub$ult/= 7.71 C$\sub$u/ similar to that of Tschebotarioff and JHI.

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단말뚝 거동에 관한 원심모형실험 (Centrifuge Model Experiments on Behaviors of Single Pile)

  • 유남재;이명욱;이종호
    • 산업기술연구
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    • 제17권
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    • pp.111-118
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    • 1997
  • This thesis is an experimental research of investigating behavior of single pile, subjected to the vertical compression loads, using the centrifuge facility located in the geotechnical engineering laboratory in Kangwon National University. Centrifugal model experiments of model pile were carried out changing diameter of model pile, relative density of sandy ground and the gravitational level applied in the centrifuge. Thus, their effects on the load-settlement behavior and the ultimate bearing capacity of pile were investigated. Experimental results obtained from centrifuge model tests were compared with the theoretical or semi-empirical equations to analyze values of ultimate bearing capacity of model pile. When we compare the ultimate bearing capacity of experimental results with the ultimate bearing capacity of theorical results, the experimental results appear more higher in the De Beer method and Meyerhof. Expecially, Terzaghi method is very same as the experimental results normally.

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압밀이론에 의한 침하량과 현장계측 침하량의 차에 의한 측방유동 침하량 산정 (Estimation of Settlement Caused by Lateral Displacement by Means of the Differences of Settlements from Consolidation Theory and Field Measurement)

  • 강민수;전상옥;임성훈
    • 한국농공학회논문집
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    • 제51권5호
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    • pp.59-68
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    • 2009
  • In this study, it was developed that the software could be used to estimate consolidation settlement by curve fitting method according to Terzaghi's consolidation theory on the condition of gradual incremental loading, and the method of estimating settlement caused by lateral displacement was suggested, in which the settlement was calculated from the difference between the settlement calculated with the developed software using the early part of measured data and the settlement measured for the short duration from the beginning of embankment in the field. The verification of the suggested method of estimating settlement caused by lateral displacement showed good results.

신뢰성이론에 의한 말뚝기초의 안정해석 및 설계규준 (Reliability Based Stability Analysis and Design Criteria for pile Foundation)

  • 이증빈;김영인;박철수;이정식;신형우
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1991년도 가을 학술발표회 논문집
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    • pp.102-107
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    • 1991
  • This study a reliability based design criteria for the Pile foundation, Which is common type of bridge founfation, and also proposes the theoretical bases limit state equations of stalbility analvsis of Pile foundation and the uncertainty measuring algorithms of each equation are also derived by MFOSM using the pile reations of displacement method, Terzaghi's bearing capacity formula, and chang's lateral load formula. The Level of uncertainties comesponding to these algorithms are proposed approprite values considering our actuality. It may be asserted that the proposed LRFD reliability based design criteria for the pile foundation may have to be incorporated in to the current Highway Bridge Design codes as a design provision corresponding to the USD(or LFD) provisions of the current Highway Bridge Design Code.

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비선형 유한변형률 압밀이론을 이용한 압밀 해석 프로그램 개발 (Development of a Program for Consolidation Analysis Using Nonlinear Finite Strain Consolidation Theory)

  • 이송;이규환;전제성
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1999년도 연약지반처리위원회 학술세미나
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    • pp.36-47
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    • 1999
  • Terzaghi's theory of one-dimensional consolidation is restricted in its applicability to relatively thin layers and small incremental loading. Because it is assumed to infinitesimal strain and linear material function. For this reason, Gibson et al established a rigorous formulation for the one-dimensional nonlinear finite strain consolidation theory. There are some difficulties in the application of finite strain consolidation theory. The developed program consisted of several forms and modules. These forms and modules with graphic-user-interfaced format are used in analysis of consolidation practices. For the purpose of verification of developed program. the results of case study and prediction of developed program are compared. The results of comparison is fairly well with prediction and measured data. And with varying finite strain consolidation parameter, g(e) or λ(e), the sensitivity of predicted values were examined.

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1차원 압밀 F.D.M 해석의 최적도식(Scheme) 연구 (Study for the Pertinent Scheme of the One Dimensional FDM Analysis)

  • 김팔규;김지호;구기욱;류권일
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 봄 학술발표회 논문집
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    • pp.631-638
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    • 2000
  • Pioneering work by Terzaghi imparted scientific and mathematical bases to many aspects of this subject and many people use this theory to measure the consolidation settlement until now. In this paper, Finite Difference Methods for consolidation are considered. First, it is shown the stability criterion of Explicit scheme and the Crank-Nicolson scheme, although unconditionally stable in the mathematical sense, produces physically unrealistic solutions when the time step is large. it is also shown that The Fully Implicit scheme shows more satisfactory behavior, but is less accurate for small time steps. and then we need to decide what scheme is more proper to consolidation. The purpose of this paper is to suggest the pertinent scheme to consolidation.

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다층 지반의 2차원 압밀 수치해석 (2-D Consolidation Numerical Analysis of Multi_Layered Soils)

  • 김팔규;류권일;남상규;이재식
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 봄 학술발표회 논문집
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    • pp.467-474
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    • 2000
  • The application of Terzaghi's theory of consolidation for analysing the settlement of multi-layered soils is not strictly valid because the theory involves an assumption that the soil is homogeneous. The settlement of stratified soils with confined aquifer can be analysed using numerical techniques whereby the governing differential equation is replaced by 2-dimensional finite difference approximations. The problems of discontinuous layer interface are very important in the algorithm and programming for the analysis of multi-layered consolidation using a numerical analysis, finite difference method(F.D.M.). Better results can be obtained by the process for discontinuous layer interface, since it can help consolidation analysis to model the actual ground The purpose of this paper provides an efficient computer algorithm based on numerical analysis using finite difference method(F.D.M) which account for multi-layered soils with confined aquifer to determine the degree of consolidation and excess pore pressures relative to time and positions more realistically.

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부산신항 사석층 침하를 고려한 안벽기초의 침하량 분석

  • 강연익;정종범;양상용
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2007년도 추계학술대회 및 제23회 정기총회
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    • pp.176-178
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    • 2007
  • 부산신항 북컨테이너터미널 민차부두 1단계 공사에 적용된 안벽기초는 하부 대섬도 연약점토층 개량을 위한 SCP(Sand Compaction Pile) 개량층과 그 상부에 약 6m정도의 사석층으로 구성되어 있다. 안벽은 케이슨식으로 상부의 크레인 풍의 공용하중 작용시에 발생이 예상되는 안벽기초의 과도한 지반침하 방지를 위해 근고블럭에 의한 Preloading 공법이 적용되었다. 따라서, 프리로딩에 의한 하부기초지반의 침하관리가 중요 공사관리 포인트가 된다. 그러나, SCP층이나 사석총에 대한 침하량 예측은 반경험적 방법에 의존하기 때문에 실제와 상당한 차이가 발생하게 된다 본 연구에서는 사석층의 진동다짐에 의한 시공 특성을 반영하기 위해 굴착치환구간의 사석층에 대한 실측값을 이용하여 Terzaghi 변형식의 침하계수 a를 재산정하여 SCP개량구간에 적용함으로써 보다 합리적인 안벽기초의 침하량을 분석하였고 이를 사석층의 여성고 산정에 이용하였다.

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