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Kui Hua Wang - One of the best experts on this subject based on the ideXlab platform.

  • Vertical vibration of an end bearing Pile interacting with the radially inhomogeneous saturated soil
    Ocean Engineering, 2021
    Co-Authors: Yufeng Gao, Kui Hua Wang
    Abstract:

    Abstract This study aims at portraying the vertical vibration characteristics of an end bearing Pile interacting with the saturated soil that is of distinctly inhomogeneous behavior in the radial direction due to the construction disturbance. The Pile is considered a one-dimensional bar. The saturated soil is considered by the Biot's two-phase linear theory and its radial inhomogeneity is simulated by the gradual variation of soil properties radially in a linear way. In practical terms, it is partitioned into a number of vertical ring-shaped zones in the radial direction with the soil properties approximately remain the same within the same soil zone. The Pile–soil dynamic interaction is then obtained by solving the governing equations of each soil zone and is substituted into the governing equation of the Pile to derive the analytical solution for the dynamic impedance at the Pile head. The present solution is validated by comparing with other solutions. Meanwhile, it is employed to investigate the effect of the construction disturbance on the vertical vibration of the Pile for different Pile–soil parameters.

  • Torsional vibration of an end bearing Pile embedded in radially inhomogeneous saturated soil
    Computers and Geotechnics, 2019
    Co-Authors: Yufeng Gao, Kui Hua Wang
    Abstract:

    Abstract This paper is concerned with the torsional dynamic response of an end bearing Pile embedded in radially inhomogeneous saturated soil. The soil is simulated using Biot’s two-phase linear theory and its radial inhomogeneity due to the construction disturbance effect is considered by radially gradual variation of soil parameters. Then, the governing equations for the Pile–soil system are established to derive an analytical solution for the torsional vibration of the Pile. The reliability of the proposed solution is verified and parametric studies are performed to analyze the torsional vibration characteristics of the Pile.

  • dynamic torsional response of an end bearing Pile in transversely isotropic saturated soil
    Journal of Sound and Vibration, 2009
    Co-Authors: Kui Hua Wang, Zhiqing Zhang, Chin Jian Leo, Kanghe Xie
    Abstract:

    Abstract The dynamic response of an end bearing Pile embedded in transversely isotropic saturated soil and subjected to a time-harmonic torsional loading is investigated. Based on the dynamic wave equations of saturated soil and the stress–strain relationships of transversely isotropic medium, the dynamic governing equations of the transversely isotropic saturated soil are derived in cylindrical coordinates and the Pile is modeled using one-dimensional elastic theory. At first, the torsional response of the soil layer is solved by using the separation of variables technique. Then by utilizing the boundary and continuity conditions of the Pile–soil system, the dynamic response of the Pile is obtained in a closed form in the frequency domain. By virtue of inverse Fourier transform and convolution theorem, a quasi-analytical solution for the velocity response of a Pile subjected to a semi-sine wave exciting torque is obtained in the time domain. Finally, a parametric study has been undertaken to investigate the influence of the soil anisotropy on the torsional vibration characteristics of the Pile, and the results obtained are presented in this paper.

  • dynamic torsional response of an end bearing Pile in saturated poroelastic medium
    Computers and Geotechnics, 2008
    Co-Authors: Kui Hua Wang, Zhiqing Zhang, Chin Jian Leo, Kanghe Xie
    Abstract:

    Abstract A comprehensive analytical solution is developed in this paper to investigate the torsional vibration of an end bearing Pile embedded in a homogeneous poroelastic medium and subjected to a time-harmonic torsional loading. The poroelastic medium is modeled using Biot’s two-phased linear theory and the Pile using one-dimensional elastic theory. By using the separation of variables technique, the torsional response of the soil layer is solved first. Then based on perfect contact between the Pile and soil, the dynamic response of the Pile is obtained in a closed form. Numerical results for torsional impedance of the soil layer are presented first to portray the influence of wave modes, slenderness ratio, Pile–soil modulus ratio and poroelastic properties. A comparison with the plane strain theory is performed. The selected numerical results are obtained to analyze the influence of the major parameters on the torsional impedance at the level of the Pile head. Finally, the dynamic torsional impedance of this study is compared with that for floating Pile in elastic soil.

Xuan-ming Ding - One of the best experts on this subject based on the ideXlab platform.

  • Influence of Pile Geometry on Responses of End-Bearing Pile Groups Subjected to Vertical Dynamic Loads
    International Journal of Structural Stability and Dynamics, 2020
    Co-Authors: Lubao Luan, Cheng Long Wang, Xin Deng, Weiting Deng, Xuan-ming Ding
    Abstract:

    An analytical solution is presented for evaluating the dynamic responses of Pile groups subjected to vertical harmonic loads. The solution allows us to consider the effects of Pile geometry on the ...

  • Influence of Pile Geometry on Responses of End-Bearing Pile Groups Subjected to Vertical Dynamic Loads
    International Journal of Structural Stability and Dynamics, 2020
    Co-Authors: Lubao Luan, Cheng Long Wang, Xin Deng, Weiting Deng, Xuan-ming Ding
    Abstract:

    An analytical solution is presented for evaluating the dynamic responses of Pile groups subjected to vertical harmonic loads. The solution allows us to consider the effects of Pile geometry on the Pile head impedance of the vertically loaded Pile groups by the use of a new dynamic interaction factor. To this end, the stress distributions of the soil surrounding the vertically vibrating Pile is first determined for calculating the Pile–Pile interaction factor, instead of the classical interaction factor based on two-Pile displacements in past studies. Accordingly, the impedances of the Pile group are derived using the proposed Pile–Pile interaction factor and the superposition principle. Some selected examples are presented to demonstrate the proposed refined technique for evaluating the dynamic characteristics of the Pile group.

  • A simplified design method for energy Piles
    Acta Geotechnica, 2019
    Co-Authors: Han-long Liu, Gang-qiang Kong, Xuan-ming Ding, Cheng Long Wang, Abdelmalek Bouazza
    Abstract:

    This paper introduces a simplified method to investigate the influence of thermal loads on the shaft friction and tip resistance of energy Piles. The method is based on the influence factors (λ and η) which are back-calculated drawing on a large number of field and model tests. Values for λ and η during heating and cooling are suggested. Moreover, a new equation is proposed to calculate total shaft friction. The equations concerning the relationship between η and temperature difference are recommended to investigate the impacts of the thermal load on the Pile tip resistance. The slope of the linear equation of an End-Bearing Pile is 2.14 times that of a floating Pile indicating that the Pile tip resistance of an End-Bearing Pile is much more affected by the same thermal load.

  • A revised solution for the horizontal vibration of an end‐bearing Pile in viscoelastic soil
    International Journal for Numerical and Analytical Methods in Geomechanics, 2016
    Co-Authors: Han-long Liu, Xuan-ming Ding, Changjie Zheng, George P. Kouretzis, Scott W. Sloan
    Abstract:

    This note presents a new method to derive closed-form expressions describing the horizontal response of an End-Bearing Pile in viscoelastic soil subjected to harmonic loads at its head. The soil surrounding the Pile is assumed as a linearly viscoelastic layer. The propagation of waves in the soil and Pile is treated mathematically by three-dimensional and one-dimensional theories, respectively. Unlike previous studies of the problem, the formulation presented allows the governing equations of the soil to be solved directly, eliminating the need to introduce potential functions. Accordingly, the dynamic response of the Pile is obtained by means of the initial parameter method, invoking the requirement for continuity at the Pile–soil interface. It is demonstrated that the derived compact solution matches exactly an existing solution that utilises potential functions to formulate the problem

  • Vertical impedance of an End-Bearing Pile in viscoelastic soil
    International Journal for Numerical and Analytical Methods in Geomechanics, 2014
    Co-Authors: Changjie Zheng, Xuan-ming Ding
    Abstract:

    Summary This paper presents a new method to derive the analytical solution for the vertical impedance of an End-Bearing Pile in viscoelastic soil. The soil is assumed as a homogeneous and isotropic layer, and the Pile is considered as a one-dimensional Euler rod. Considering both the vertical and radial displacements of soil and soil–Pile coupled vibration, the governing equations of the soil and Pile are established. The volumetric strain of soil is obtained by transformation on the equations of soil and variable separation method. Then the vertical and radial displacements of soil are obtained accordingly. The displacement response and impedance function of Pile are derived based on the continuity assumption of the displacement and stress between the Pile and soil. The solution is verified by being compared with an existing solution obtained by introducing potential functions. Furthermore, a comparison with two other simplified solutions is conducted. Numerical examples are presented to analyze the vibration characteristics of the Pile. Copyright © 2014 John Wiley & Sons, Ltd.

Bijan Samali - One of the best experts on this subject based on the ideXlab platform.

  • physical modeling of seismic soil Pile structure interaction for buildings on soft soils
    International Journal of Geomechanics, 2015
    Co-Authors: Aslan S. Hokmabadi, Behzad Fatahi, Bijan Samali
    Abstract:

    AbstractThe present research intends to study the effects of the seismic soil-Pile-structure interaction (SSPSI) on the dynamic response of buildings with various heights by conducting a series of shaking table tests on 5-, 10-story, and 15-story model structures. Two types of foundations for each case are investigated, including (1) a fixed-base structure, representing the situation excluding the soil-structure interaction; and (2) a structure supported by an End-Bearing Pile foundation in soft soil. An advanced laminar soil container has been designed that uses three-dimensional numerical modeling to minimize the boundary effects and to simulate free-field motion during the shaking table tests. Four real earthquake events, including Kobe 1995, Northridge 1994, El Centro 1940, and Hachinohe 1968, are imposed to each model. According to the experimental measurements, it is observed that the SSPSI amplifies the maximum lateral deflections and in turn interstory drifts of the structures supported by end-bea...

  • RETRACTED: Seismic response of mid-rise buildings on shallow and End-Bearing Pile foundations in soft soil
    Soils and Foundations, 2014
    Co-Authors: Aslan S. Hokmabadi, Behzad Fatahi, Bijan Samali
    Abstract:

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).The Editorial committee has carefully reviewed this article and 'Assessment of soil–Pile–structure interaction influencing seismic response of mid-rise buildings sitting on floating Pile foundations' by Aslan S. Hokmabadi in Computers and Geotechnics 55 (2014) 172–186 (10.1016/j.compgeo.2013.08.011). Although there was a difference in the Pile type of "floating Pile" and "End-Bearing Pile" in both papers, each paper contained similar contents in most parts. Therefore the Editorial committee has decided to retract the article “Seismic response of mid-rise buildings on shallow and End-Bearing Pile foundations in soft soil” from "Soils and Foundations".The authors have not properly referenced and acknowledged their own previously published work in this paper, and they sincerely apologize for the inconvenience caused by this issue

Behzad Fatahi - One of the best experts on this subject based on the ideXlab platform.

  • Assessment of Soil Plasticity Effects on Seismic Response of Mid-Rise Buildings Resting on End-Bearing Pile Foundations
    Sustainable Civil Infrastructures, 2018
    Co-Authors: Behzad Fatahi
    Abstract:

    In this study, the seismic response of mid-rise buildings supported by End-Bearing Pile foundations under the influence of six different soil Plasticity Indices (PI) is investigated. FLAC3D is utilised to develop the soil-Pile-structure system and perform fully nonlinear analysis in time domain adopting the direct method. The results in terms of shear forces developed in the superstructure, lateral building displacement, maximum inter-storey drift, lateral Pile displacement and shear forces and bending moments developed along Piles are presented. The results indicate the seismic response of the soil-Pile-structure system is sensitive to the variation of PI. By considering the effects of PI, the seismic performance of the superstructure may shift from life safe zone to near collapse level. Moreover, the shear force imposed on the Piles increases with PI, particularly in the top section of the Pile near the ground surface due to the inertial interaction. Also, as PI increases, the bending moment developed in the Piles increases and no need to mention the lateral Pile displacement. Due to the load bearing mechanism, the maximum bending moment occurs at the Pile toe socketed in the bedrock. Thus, appropriate soil Plasticity Index should be considered to obtain the safe and reasonable seismic design of mid-rise buildings resting on End-Bearing Pile foundations.

  • Effects of Pile Group Configuration on the Seismic Response of Buildings Considering Soil-Pile-Structure Interaction
    Proceedings of GeoShanghai 2018 International Conference: Advances in Soil Dynamics and Foundation Engineering, 2018
    Co-Authors: Behzad Fatahi
    Abstract:

    Mid-rise buildings supported by different configurations of End-Bearing Pile foundations can fulfil the design requirements addressed in the modern building codes and selecting the most efficient configuration is a challenging task. In this study, the influence of group configuration (but keep the area replacement ratio constant) on the seismic response of mid-rise buildings resting on End-Bearing Pile foundations considering seismic soil-Pile-structure interaction (SSPSI) is investigated. A soil-Pile-structure system is simulated in FLAC3D to carry out the fully nonlinear seismic analysis in the time domain. The elastic-perfectly plastic structural behaviour is considered while the variation of soil shear modulus due to cyclic shear strain and the corresponding damping ratio is simulated adopting hysteretic damping algorithm, and the soil plastic behaviour is modelled using Mohr-Coulomb criterion. The results of the seismic Pile responses, namely the envelopes of shear forces and bending moments along the Piles and the lateral Pile displacements, and the building responses including the base shear, and the lateral building displacements are reported and discussed. It is observed that for the cases analysed, the Pile group configuration influences the seismic response of the system. Provided that the same volume of concrete (i.e. constant area replacement ratio) is used for all cases, by increasing the number of Piles but with smaller diameters, more seismic loads may be attracted to the system due to the kinematic interaction between the Piles and the surrounding soil and consequently causing the increase in the base shear and lateral displacements of the building.

  • physical modeling of seismic soil Pile structure interaction for buildings on soft soils
    International Journal of Geomechanics, 2015
    Co-Authors: Aslan S. Hokmabadi, Behzad Fatahi, Bijan Samali
    Abstract:

    AbstractThe present research intends to study the effects of the seismic soil-Pile-structure interaction (SSPSI) on the dynamic response of buildings with various heights by conducting a series of shaking table tests on 5-, 10-story, and 15-story model structures. Two types of foundations for each case are investigated, including (1) a fixed-base structure, representing the situation excluding the soil-structure interaction; and (2) a structure supported by an End-Bearing Pile foundation in soft soil. An advanced laminar soil container has been designed that uses three-dimensional numerical modeling to minimize the boundary effects and to simulate free-field motion during the shaking table tests. Four real earthquake events, including Kobe 1995, Northridge 1994, El Centro 1940, and Hachinohe 1968, are imposed to each model. According to the experimental measurements, it is observed that the SSPSI amplifies the maximum lateral deflections and in turn interstory drifts of the structures supported by end-bea...

  • RETRACTED: Seismic response of mid-rise buildings on shallow and End-Bearing Pile foundations in soft soil
    Soils and Foundations, 2014
    Co-Authors: Aslan S. Hokmabadi, Behzad Fatahi, Bijan Samali
    Abstract:

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).The Editorial committee has carefully reviewed this article and 'Assessment of soil–Pile–structure interaction influencing seismic response of mid-rise buildings sitting on floating Pile foundations' by Aslan S. Hokmabadi in Computers and Geotechnics 55 (2014) 172–186 (10.1016/j.compgeo.2013.08.011). Although there was a difference in the Pile type of "floating Pile" and "End-Bearing Pile" in both papers, each paper contained similar contents in most parts. Therefore the Editorial committee has decided to retract the article “Seismic response of mid-rise buildings on shallow and End-Bearing Pile foundations in soft soil” from "Soils and Foundations".The authors have not properly referenced and acknowledged their own previously published work in this paper, and they sincerely apologize for the inconvenience caused by this issue

Aslan S. Hokmabadi - One of the best experts on this subject based on the ideXlab platform.

  • physical modeling of seismic soil Pile structure interaction for buildings on soft soils
    International Journal of Geomechanics, 2015
    Co-Authors: Aslan S. Hokmabadi, Behzad Fatahi, Bijan Samali
    Abstract:

    AbstractThe present research intends to study the effects of the seismic soil-Pile-structure interaction (SSPSI) on the dynamic response of buildings with various heights by conducting a series of shaking table tests on 5-, 10-story, and 15-story model structures. Two types of foundations for each case are investigated, including (1) a fixed-base structure, representing the situation excluding the soil-structure interaction; and (2) a structure supported by an End-Bearing Pile foundation in soft soil. An advanced laminar soil container has been designed that uses three-dimensional numerical modeling to minimize the boundary effects and to simulate free-field motion during the shaking table tests. Four real earthquake events, including Kobe 1995, Northridge 1994, El Centro 1940, and Hachinohe 1968, are imposed to each model. According to the experimental measurements, it is observed that the SSPSI amplifies the maximum lateral deflections and in turn interstory drifts of the structures supported by end-bea...

  • RETRACTED: Seismic response of mid-rise buildings on shallow and End-Bearing Pile foundations in soft soil
    Soils and Foundations, 2014
    Co-Authors: Aslan S. Hokmabadi, Behzad Fatahi, Bijan Samali
    Abstract:

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).The Editorial committee has carefully reviewed this article and 'Assessment of soil–Pile–structure interaction influencing seismic response of mid-rise buildings sitting on floating Pile foundations' by Aslan S. Hokmabadi in Computers and Geotechnics 55 (2014) 172–186 (10.1016/j.compgeo.2013.08.011). Although there was a difference in the Pile type of "floating Pile" and "End-Bearing Pile" in both papers, each paper contained similar contents in most parts. Therefore the Editorial committee has decided to retract the article “Seismic response of mid-rise buildings on shallow and End-Bearing Pile foundations in soft soil” from "Soils and Foundations".The authors have not properly referenced and acknowledged their own previously published work in this paper, and they sincerely apologize for the inconvenience caused by this issue