• Title/Summary/Keyword: Passive pile

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A Study of Rectangular-shaped Passive Row Piles in Horizontal Sand-ground under Lateral Soil Movement by Model Test (수평모래지반에서 측방변형을 받는 사각형 수동 열말뚝에 관한 실험적 연구)

  • Bae, Jong-Soon;Kwon, Min-Jea
    • Journal of the Korean Geotechnical Society
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    • v.24 no.4
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    • pp.23-36
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    • 2008
  • This study describes model tests on instrumented rectangular-shaped passive row piles embedded in horizontal sand-ground undergoing lateral soil movement. We tried to find the property of row piles dependent on the shape of pile, including the position of the pile in row, pile spacing, and soil movement. The results of test are as follows. The lateral earth pressure diagram variously appeared to be triangle, trapezoid and rectangular by shape and position of pile. The outer pile has a larger bending moment than the inner pile in the case of B-type, the inner piles has larger one than outer pile in case of H-type. $R_f$ (the ratio of resistance to lateral soil movement) was found to increase with increasing pile spacing irrespective of pile-shape. Y/L (location of action of lateral resistance force) for $d_s$ (displacement of soil) and $S_h$ (spacing of pile) appeared to be nearly regular position, and H-type is higher than B-type.

Analysis Method of Passive Piles considering group effect (군말뚝효과를 고려한 수동말뚝의 해석기법)

  • 정상섬;원진오;김병철
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.151-158
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    • 2000
  • The lateral deformation of one row pile groups was investigated based on analytical study and a numerical analysis. The emphasis was on quantifing the load transfer of pile groups subjected to lateral soil movement. An analytical method to consider pile-soil interaction in weathered soil was developed using load-transfer curve methods. Through the comparative study, it is found that the prediction by present approach is in good agreement with the general trend observed by in-situ measurements.

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A Study on the Rectangular-Shaped Passive Row Piles in Inclined Sand-Ground by Model Test (경사모래지반의 사각형 수동 열말뚝에 관한 실험적 연구)

  • Bae, Jong-Soon;Kim, Ji-Seong;Kwon, Min-Jae
    • Journal of the Korean Geotechnical Society
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    • v.25 no.11
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    • pp.39-51
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    • 2009
  • This is a study on rectangular-shaped passive row piles in inclined sand-ground by model tests. The experiment controlled the angle of inclination of ground and induced the ground destruction. We also measured the behavior of row piles, by adjusting the shape, position and spacing of piles. As a result, we confirmed the earth pressure, the lateral resistance, and the effect of depressing on the ground variation working on passive pile. The effect of B-type pile of which the front width is wide is bigger than that of H-type pile of which the side width is wide. We can find out the failure angle of slope, the shared force of pile and soil by using the lateral resistance graph based on slope angle.

Analysis of Passive Pile Groups Subjected to Lateral Soil Movements-A Study on the Model Test- (측방변형을 받는 수동군말뚝의 거동분석-모형토조실험-)

  • 장서용;원진오;정상섬
    • Journal of the Korean Geotechnical Society
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    • v.15 no.6
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    • pp.239-249
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    • 1999
  • In this study, experimental work has been carried out to investigate the effect of lateral soil movement on passive piles. This paper consists mainly of two parts: the first, performance of a series of laboratory experiments on a single pile and one-row pile groups, and the second, comparison between the measured and the predicted results. In the laboratory experiments, a quadrilateral soil movement profile was imposed on model piles embedded in both sandy soils and weathered soils. The maximum bending moment and pile deflection induced in passive piles were found to be highly dependent on pile stiffness, pile spacing, relative densities and pile head fixity condition. It was shown that the group effect might either increase or decrease the maximum bending moment and pile deflection, depending on the aforementioned influence factors. Based on the results obtained, a spacing-to-diameter ratio of 7.0 seems to be large enough to eliminate the group effect, and a pile in such a case behaves essentially the same as a single pile.

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Response of passively loaded pile groups - an experimental study

  • Al-abboodi, Ihsan;Sabbagh, Tahsin Toma;Al-salih, Osamah
    • Geomechanics and Engineering
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    • v.20 no.4
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    • pp.333-343
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    • 2020
  • Preventing or reducing the damage impact of lateral soil movements on piled foundations is highly dependent on understanding the behavior of passive piles. For this reason, a detailed experimental study is carried out, aimed to examine the influence of soil density, the depth of moving layer and pile spacing on the behavior of a 2×2 free-standing pile group subjected to a uniform profile of lateral soil movement. Results from 8 model tests comprise bending moment, shear force, soil reaction and deformations measured along the pile shaft using strain gauges and others probing tools were performed. It is found that soil density and the depth of moving layer have an opposite impact regarding the ultimate response of piles. A pile group embedded in dense sand requires less soil displacement to reach the ultimate soil reaction compared to those embedded in medium and loose sands. On the other hand, the larger the moving depth, the larger amount of lateral soil movement needs to develop the pile group its ultimate deformations. Furthermore, the group factor and the effect of pile spacing were highly related to the soil-structure interaction resulted from the transferring process of forces between pile rows with the existing of the rigid pile cap.

Displacement of Quaywall Pile by Lateral Movement of Revetment on Soft Ground (연약지반상에 축조된 호안의 측방유동에 따른 안벽말뚝의 변위)

  • Shin, Eun-Chul;Ryu, In-Gi;Kim, Jong-In
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.932-939
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    • 2005
  • Recently, the lateral displacement of the passive piles which installed under the revetment on soft ground is very important during the land reclamation work along the coastal line. The revetment on the soft clay develops the lateral displacement of the ground when the revetment loading is exceeded a certain limit. The lateral displacement of ground causes an excessive deformation of under structure itself and develops lateral earth pressure against the pile foundation as well. Especially passive piles subjected to lateral earth pressures are likely to have excessive horizontal displacement and large bending moment, which induces structural failure of pile foundation and harmful effects on superstructure. The subject of study is to investigate the later displacement of pile foundation during the construction of container terminal at the south port of Incheon. Actual field measurement data and finite element method(FEM) by AFFIMEX Ver 3.4 were used to analyze the displacement of pile and the vertical settlement of soft ground. This analysis was carried out at each sequence of construction work.

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Study on critical buckling load calculation method of piles considering passive and active earth pressure

  • Chen, Yong-Hui;Chen, Long;Xu, Kai;Liu, Lin;Ng, Charles W.W.
    • Structural Engineering and Mechanics
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    • v.48 no.3
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    • pp.367-382
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    • 2013
  • Different types of long slender pile shall buckle with weak soil and liquefied stratum surrounded. Different from considering single side earth pressure, it was suggested that the lateral earth pressure can be divided into two categories while buckling: the earth pressure that prevent and promotes the lateral movement. Active and passive earth pressure calculation model was proposed supposing earth pressure changed linearly with displacement considering overlying load, shaft resistance, earth pressure at both sides of the pile. Critical buckling load calculation method was proposed based on the principle of minimum potential energy quoting the earth pressure calculation model. The calculation result was contrasted with the field test result of small diameter TC pile (Plastic Tube Cast-in-place pile). The fix form could be fixed-hinged in the actual calculation assuring the accuracy and certain safety factor. The contributions of pile fix form depend on the pile length for the same geological conditions. There exists critical friction value in specific geological conditions that the side friction has larger impact on the critical buckling load while it is less than the value and has less impact with larger value. The buckling load was not simply changed linearly with friction. The buckling load decreases with increased limit active displacement and the load tend to be constant with larger active displacement value; the critical buckling load will be the same for different fix form for the small values.

Lateral Force Acting on H-piles in Plastically Deforming Ground (소성변형지반 중의 H형 말뚝에 작용하는 수평력)

  • 김영인
    • Journal of Ocean Engineering and Technology
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    • v.15 no.4
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    • pp.86-91
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    • 2001
  • In lateral ground flow, slope stability, and land slide problems, H-piles have been often used for a horizontally deforming ground to prevent the failure of mass of soil in a downward and outward movement of a slope. Here, Theoretical equations are derived to estimate the lateral force, assuming that the Mohr-coulomb's Plastic states occures in the ground just around H-piles. In this study, the mechanism of lateral force acting on passive pile that is in a row, situated in the ground undergoing plastic deformation was discussed, and its theoretical analysis was carried out considering the interval between H-piles. The solution of the theoretical equation derived from here showed resonable characteristic for constants of soil as well as for the interval, widths, and heights of H-pile.

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Numerical FEM assessment of soil-pile system in liquefiable soil under earthquake loading including soil-pile interaction

  • Ebadi-Jamkhaneh, Mehdi;Homaioon-Ebrahimi, Amir;Kontoni, Denise-Penelope N.;Shokri-Amiri, Maedeh
    • Geomechanics and Engineering
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    • v.27 no.5
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    • pp.465-479
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    • 2021
  • One of the important causes of building and infrastructure failure, such as bridges on pile foundations, is the placement of the piles in liquefiable soil that can become unstable under seismic loads. Therefore, the overarching aim of this study is to investigate the seismic behavior of a soil-pile system in liquefiable soil using three-dimensional numerical FEM analysis, including soil-pile interaction. Effective parameters on concrete pile response, involving the pile diameter, pile length, soil type, and base acceleration, were considered in the framework of finite element non-linear dynamic analysis. The constitutive model of soil was considered as elasto-plastic kinematic-isotropic hardening. First, the finite element model was verified by comparing the variations on the pile response with the measured data from the centrifuge tests, and there was a strong agreement between the numerical and experimental results. Totally 64 non-linear time-history analyses were conducted, and the responses were investigated in terms of the lateral displacement of the pile, the effect of the base acceleration in the pile behavior, the bending moment distribution in the pile body, and the pore pressure. The numerical analysis results demonstrated that the relationship between the pile lateral displacement and the maximum base acceleration is non-linear. Furthermore, increasing the pile diameter results in an increase in the passive pressure of the soil. Also, piles with small and big diameters are subjected to yielding under bending and shear states, respectively. It is concluded that an effective stress-based ground response analysis should be conducted when there is a liquefaction condition in order to determine the maximum bending moment and shear force generated within the pile.

A Study on Lateral Movement of Bridge Abutment on Soft Ground (연약지반상 교대의 측방이동에 관한 연구)

  • 홍원표;한중근
    • Geotechnical Engineering
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    • v.10 no.4
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    • pp.53-66
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    • 1994
  • In case of using pile foundation to support bridge abutments on soft ground, the soft ground often causes serious troubles such as lateral movement of the bridge abutments. The foundation piles in soil undergoing lateral movement is one of the typical passive piles. However, Generally, on design of the piles for abutments, the piles have not been considered as a passive piles; sofar:. Because it is difficult to assess the effect of the lateral movement on the desigin and reasonable design method is not established yet. In this study, several abutments, of which lateral movement was taken place, was investigated. Based on the investigation a criterion was presented to assess the lateral movement of the soft soil under backfill for abutment. By use of the criterion, the lateral movement of abutment could be predicted. As the results of thin study, it was anon that the lateral movement of abutment could be occured when the safety factor of slope stability is lese than either 1.5(without the pile effect) or 1.8 (with the pile effect). Especially, excessive lateral movements were occurred when the safety factor of slope stability is less than either 1.0(without the pile effect) or 1.1 (with the pile effect).

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