• Journal of the Korean Geotechnical Society
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• v.26 no.11
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• pp.39-46
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• 2010

The magnitude of the lateral resistance that resists the lateral movement of the pile is controlled by the amount of the pile movement and the strength and stiffness of soil. In this paper, we proposed an equation which produces the lateral resistance of the laterally loaded single pile using the strain wedge model of the soil deformation. The results of this equation is compared with results of model test, field test, p-y curve and other methods. It is found that the result of proposed equation is smaller than the result of model test. The results of loading test considerably coincide with those of proposed equation; however, a few of deviations are generated as the displacement of pile head increases. Moreover, coincidences exist between the results of the proposed equation and those of finite difference method.

• Geomechanics and Engineering
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• v.34 no.5
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• pp.529-545
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• 2023

The coupled soil-pile-structure seismic response is recently in the spotlight of researchers because of its extensive applications in the different fields of engineering such as bridges, offshore platforms, wind turbines, and buildings. In this paper, a simple analytical model is developed to evaluate the dynamic performance of seismically isolated bridges considering triple interactions of soil, piles, and bridges simultaneously. Novel expressions are proposed to present the dynamic behavior of pile groups in inhomogeneous soils with various shear modulus along with depth. Both cohesive and cohesionless soil deposits can be simulated by this analytical model with a generalized function of varied shear modulus along the soil depth belonging to an inhomogeneous stratum. The methodology is discussed in detail and validated by rigorous dynamic solution of 3D continuum modeling, and time history analysis of centrifuge tests. The proposed analytical model accuracy is guaranteed by the acceptable agreement between the experimental/numerical and analytical results. A comparison of the proposed linear model results with nonlinear centrifuge tests showed that during moderate (frequent) earthquakes the relative differences in responses of the superstructure and the pile cap can be ignored. However, during strong excitations, the response calculated in the linear time history analysis is always lower than the real conditions with the nonlinear behavior of the soil-pile-bridge system. The current simple and efficient method provides the accuracy and the least computational costs in comparison to the full three-dimensional analyses.

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.103-112
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• 2012

The most of original horizontal bearing capacity theory of the pile is not efficiently to consider interaction between soil and pile because it is only to consider the earth pressure theory and separately the ground form pile. In recent, in order to improve the pile technology, it is necessary to confirm the real behaviour characteristics of pile under lateral load. Hence, to evaluate the behaviour characteristics of the single and group pile under lateral loads using the strain wedge model that could consider the interaction between soil and piles. Primarily, laboratory scale down model tests was carried out to predict the behaviour characteristics on real size piles using the strain wedge model. The comparative analyses between model test and numerical analysis for the evaluation of whole behaviour were conducted.

• 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.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.167-185
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• 1999

A series of model tests was performed to find the characteristics of lateral behavior of single rigid pile. This paper shows the results of model tests on the lateral behavior of single rigid driven pile in non-homogeneous(two layered) Nak-Dong River sands. The purpose of this paper is to investigate the effect of the ratio of lower layer thickness to embedded pile length, the coefficient ratio of the subgrade reaction and the pile construction conditions(driven & embedded piles) on the characteristics of lateral behavior of single pile. The results of model tests show that the lateral behavior in non-homogeneous soil depends upon drop energy considerably, that is, in the case of H/L=0.75, as the drop energy increases three times the decrease percentage increases about 2.12 times. In the driven pile with non-homogeneous soil of $E_{h1}/E_{h2}=5.56$, the effect of upper layer with large stiffness on the decrease of lateral deflection is remarkably smaller than embedded pile. In non-homogeneous soil, the maximum bending moment of driven pile is in the range of 100 132% in comparison with embedded pile. The reason is that the stiffness of soil around pile increases with drop vibration and so the pile behavior is similar to the flexible pile behavior by means of the increase of relative stiffness of pile, In this paper, the experimental equations for lateral load and H/L on $y_D/y_E \; & \; MBM_D/MBM_E$ are suggested from model tests.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.445-448
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• 2001

Noise radiated from pile driving operation is one of major sources of community noise pollution and thus its operation method is strictly restricted by regulations. Although the drilling method is now used been commonly used in urban areas because of its activity, the benefit of low noise decreases due to high working cost. In the present work, noise characteristics of pile driving operation are carried out. Based on the study result, a low-noise pile cap for driven piles is developed in order to satisfy both the noise level restriction and the economical efficiency. Effects of pile cap are investigated by a scale model experiment, which is focused on the variation of impact force and sound pressure level. The results show a good possibility of noise reduction by an appropriately designed pile cap.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.397-404
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• 2002

The bearing capacity of open-ended piles is affected by the degree of soil plugging, which is quantified by the IFR. There is not at present a design criterion for open-ended piles that explicitly considers the effect of IFR on pile load capacity In order to investigate this effect, model pile load tests using a calibration chamber were conducted on instrumented open-ended piles. The results of these tests show that the IFR increases with increasing relative density and increasing horizontal stress of soils. The unit base and shaft resistances decrease with increasing IFR. Based on the results of the model pile tests, new empirical relations for base load capacity and shaft load capacity of open-ended piles are proposed. In order to check the accuracy of predictions made with the proposed equations, the equations were applied to the full-scale pile load test preformed in this study, Based on the comparisons with the pile load test results, the proposed equations appear to produce satisfactory predictions.

• Geomechanics and Engineering
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• v.32 no.1
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• pp.21-34
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• 2023

In order to analyze the effect of the cyclic lateral loading on the response of a pile-soil system, a full-scale single steel pile was subjected to one-way cyclic loading. The test pile was driven into a bi-layered soil consisting of a normally consolidated saturated clay overlying a silty sandy layer, the site being submerged by water up to one meter above the mudline in order to reproduce the conditions of an offshore pile foundation. The aim of this paper is to present the main results of interpretation of the cyclic lateral tests in terms of pile deflections, bending moment, and cyclic P-Y curves. From these latter an absolute secant reaction modulus E_AS,N was derived and a simple calculation model of the test single pile is proposed based on this modulus. Two applications of the proposed model are carried out, one with a 2D finite element modelling, and the second with a load transfer curves-based method.

• 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.

• Journal of the Korean GEO-environmental Society
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• v.10 no.5
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• pp.69-73
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• 2009

In this study, three dimensional numerical analyses were performed with variation of pile spacing (S=3D, 4D, 5D) to compare the behaviour of single pile and pile group with cap in granite soil. In order to compare and analyze the lateral resistance of single pile and pile group by changing pile spacing, the pile group with array of $1{\times}3$ was employed. To reduce the computation time the symmetric boundary condition was used. And Druker-Prager model and elasticity model were used for granite soil and for concrete pile and cap, respectively. Using the analyses results of pile group in granite soil under lateral loading, p-y curve for pile group and single pile with changing pile spacing was drawn. With p-y curve p-multiplier was evaluated. As a result of analysis, the value of p-multiplier was increased with increasing pile spacing under 1.0 due to pile shadow effects.