The influence of pile displacement on soil plug capacity of open-ended pipe pile in sand

The apparent phase velocity of open-ended pipe piles after installation is difficult to predict owing to the soil-plug effect. This paper derives an analytical solution to calculate the apparent phase velocity of a pipe pile segment with soil-plug filling inside (APVPSP) based on the additional mass model. The rationality and accuracy of the developed solution are confirmed through comparison with the solution derived using the soil-plug Winkler model and experimental results. A parameter combination of the additional mass model that can be applied to concrete pipe piles used most commonly is recommended. The attenuation mechanism of the soil plug on the APVPSP is clarified. The findings from this study demonstrate that the APVPSP decreases with the mass per unit length of the pile, but has nothing to do with the material longitudinal wave velocity of the pipe pile. The APVPSP decreases significantly as the impulse width increases; however, for pipe piles without soil-plug filling inside, the impulse width has negligible influence on the apparent phase velocity.

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Improved soil plug height calculation formula

Scientific Research and Reviews ◽

10.28933/srr-2021-02-1805 ◽

2021 ◽

pp. 121

Author(s):

Keyword(s):

Theoretical Calculation ◽

Balance Equation ◽

Vertical Direction ◽

Calculation Formula ◽

Force Analysis ◽

Soil Plug ◽

Pipe Pile ◽

Calculation Results ◽

Open Pipe ◽

Multiple Units

This paper analyzes the soil plugging effect of the open pipe pile during the pile sinking process. The soil in the pipe pile is regarded as a continuous and uninterrupted multiple units, and the force analysis is carried out in the vertical direction, and the vertical balance equation of the soil in the pile is obtained. By establishing an equation, the expression of the plug height of the pipe pile during the pile sinking process is obtained. Comparing the theoretical calculation results with the actual project, it is concluded that the theoretical calculation results can reflect the overall change in the height of the soil plug. Therefore, the pile plug height obtained by calculation has certain guiding significance for the project.

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Mechanisms of soil plug formation of open-ended jacked pipe pile in clay

Computers and Geotechnics ◽

10.1016/j.compgeo.2019.103334 ◽

2020 ◽

Vol 118 ◽

pp. 103334 ◽

Cited By ~ 2

Author(s):

Teng Wang ◽

Yu Zhang ◽

Xingxian Bao ◽

Xiaoni Wu

Keyword(s):

Soil Plug ◽

Pipe Pile ◽

Plug Formation

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New interaction model for vertical dynamic response of pipe piles considering soil plug effect

Canadian Geotechnical Journal ◽

10.1139/cgj-2016-0309 ◽

2017 ◽

Vol 54 (7) ◽

pp. 987-1001 ◽

Cited By ~ 33

Author(s):

Wenbing Wu ◽

M. Hesham El Naggar ◽

Maged Abdlrahem ◽

Guoxiong Mei ◽

Kuihua Wang

Keyword(s):

Analytical Solution ◽

Dynamic Response ◽

Dynamic Testing ◽

Interaction Model ◽

Function Technique ◽

Actual Behavior ◽

Additional Mass ◽

Mass Model ◽

Soil Plug ◽

Pipe Pile

A soil–pile interaction model is developed to better represent the actual behavior of pipe piles undergoing dynamic testing. To correctly investigate the dynamic interaction mechanism of the pipe piles, the developed model introduces an additional mass to account for the soil plug. The governing equations of motion for the soil–pile system subjected to small deformations and strains are established considering plane strain conditions for the soil and one-dimensional wave propagation in the pile. The analytical solution of the vertical dynamic response of the pipe pile in the frequency domain is then obtained by employing a Laplace transform and transfer function technique. The corresponding quasi-analytical solution in the time domain for the pipe pile subjected to a vertical semi-sinusoidal exciting force is subsequently derived by means of a Fourier transform. A parameter sensitivity analysis of the additional mass model is carried out to determine the approximate range of the parameter values. Utilizing the developed solution, a parametric study is performed to illustrate the influence of the properties of the soil–pile system on the vertical dynamic response of the pipe pile. Finally, the validity of the additional mass model is validated by conducting a set of model tests, based on which the concept of “apparent wave velocity of pipe pile” (AWVPP) is also proposed.

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One dimensional wave propagation analysis of an open-ended pipe pile with consideration of the excess pore pressure in soil plug

Frontiers in Offshore Geotechnics ◽

10.1201/noe0415390637.ch95 ◽

2005 ◽

Author(s):

A Numata ◽

T Matsumoto ◽

T Wakisaka

Keyword(s):

Wave Propagation ◽

Pore Pressure ◽

Excess Pore Pressure ◽

Soil Plug ◽

Pipe Pile ◽

One Dimensional ◽

Propagation Analysis ◽

Dimensional Wave ◽

Excess Pore

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Dynamic Response of Offshore Open-Ended Pile under Lateral Cyclic Loadings

Journal of Marine Science and Engineering ◽

10.3390/jmse7050128 ◽

2019 ◽

Vol 7 (5) ◽

pp. 128 ◽

Cited By ~ 6

Author(s):

Junwei Liu ◽

Zhen Guo ◽

Na Zhu ◽

Hui Zhao ◽

Ankit Garg ◽

...

Keyword(s):

Large Scale ◽

Lateral Pressure ◽

Formation Rate ◽

Dynamic Responses ◽

Offshore Wind ◽

Soil Plug ◽

Pipe Pile ◽

Pile Diameter ◽

Number Of Cycles ◽

Surrounding Soil

Foundations for offshore wind turbines (OWTs) are mainly open-ended piles that are subjected to cyclic loadings caused by winds, waves and currents. This study aims to investigate the dynamic responses of open-ended pipe pile under lateral cyclic loadings, as well as the characteristics of the soil plug and surrounding soil. Both large-scale indoor model test and discrete element simulation were adopted in this study. The test results show that the resistance of each part of the pipe pile increases linearly with depth during the process of pile driving. The pile side resistance degradation effect was also observed along with the friction fatigue. The soil plug formation rate decreases gradually with an increase in the pile depth. The influence range in the surrounding soil is about 5~6 times of the pile diameter. The cumulative displacement of the pile head increases with the number of cycles. Lateral tangential stiffness and lateral ultimate bearing capacity decreases with an increase in number of cycles. The severe disturbance range of soil around the pile is 2~3 times of the pile diameter. The center of rotation of the pile body is about 0.8 times of the pile body depth. The side frictional resistance and lateral pressure of the pile body is found to fluctuate along the pile body. Additionally, the lateral pressure and side friction resistance decreases gradually with decreasing tendency of the former more than the latter.

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