Finite element model for piles in liquefiable ground

Wang, Rui; Fu, Pengcheng; Zhang, Jianmin

doi:10.1016/j.compgeo.2015.10.009

Cited by 75 publications

(24 citation statements)

References 49 publications

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“…Structural models in centrifuge tests practically remained elastic; thereby inelastic damage patterns of widely used RC pile structures are not well documented. 1 Except for tests, major numerical studies fell into the estimates of pile behavior in liquefiable soils (e.g.,, [26][27][28][29] among others), while rare studies focused on the seismic behavior of bridges in liquefiable soils. So far, only three such tests, each in US, 23 Japan 24 and Italy, 25 have been performed on piles without supported structures.…”

Section: Introductionmentioning

confidence: 99%

“…It should be noted that most of these shake-table tests concentrated on kinematic effects on the failure mechanism, while neglecting superstructure-induced inertial forces that have been proved to be an important source for bridge failures in liquefied soils. 1 Except for tests, major numerical studies fell into the estimates of pile behavior in liquefiable soils (e.g.,, [26][27][28][29] among others), while rare studies focused on the seismic behavior of bridges in liquefiable soils. [30][31][32] To date, due to inherent complexities of soilstructure interaction and liquefaction, studies on seismic failure mechanism of bridges in liquefied soils are still warranted.…”

Section: Introductionmentioning

confidence: 99%

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Shake‐table investigation of scoured RC pile‐group‐supported bridges in liquefiable and nonliquefiable soils

Wang

Shang

2019

Earthq Engng Struct Dyn

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Summary This paper presents results of one‐g shake‐table tests on scoured pile‐group‐supported bridge models in saturated (liquefiable) and dry (nonliquefiable) sands. The primary objective is to reveal the influence of liquefaction on seismic demands and failure mechanism of scoured bridges. To this end, two identical models, each consisting of a 2 × 2 reinforced concrete pile‐group with a center‐to‐center spacing of 3 times pile diameter, a cap and a single pier with a lumped iron block, were constructed and embedded into saturated and dry sands, respectively, with the same scour depth of 4 times pile diameter. Typical test results, including excess pore pressure, acceleration and displacement demands are interpreted first, followed by the focus on curvature demands and associated seismic failure mechanism identification. Finally, inertial and kinematic effects on pile curvature demands are estimated using cross‐correlation analyses. Results show that near‐pile liquefied soils exhibit more remarkable dilation tendency as compared to far field. For bridges under the given scour depth, soil liquefaction tends to significantly affect the failure modes via transferring damage positions from pier bottom to pile head and meanwhile from underground pile to pile head. In addition, pile group effects appear to be significant in nonliquefiable soils while to be relatively inessential in liquefied soils. Moreover, the inertial effect is more prominent in nonliquefiable soils, while the kinematic effect itself generally appears to be more significant in liquefiable soils. The test results can be used to validate numerical models for future studies.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Shake‐table investigation of scoured RC pile‐group‐supported bridges in liquefiable and nonliquefiable soils

Wang

Shang

2019

Earthq Engng Struct Dyn

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“…The u-P formulation (called EightNodeBrick-u-P element in OpenSees framework) is the simplification of the u-p-U approach, which captures the movements of the soil skeleton (u) and the change of the pore pressure (P). More detail about description, formulation and implementation of this theory can be found in [120][121][122]. Figure 10 is an example of three numerical modelling of pile in liquefiable of soil.…”

Section: Two-and Three-dimensional Numerical Modellingmentioning

confidence: 99%

The Dynamic Behaviour of Pile Foundations in Seismically Liquefiable Soils: Failure Mechanisms, Analysis, Re-Qualification

Rostami¹,

Hytiris²,

Bhattacharya³

2021

Earthquakes - From Tectonics to Buildings

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This chapter presents a concise overview of the mechanics of failure, analysis and requalification procedures of pile foundations in liquefiable soils during earthquakes. The aim is to build a strong conceptual and technical interpretation in order to gain insight into the mechanisms governing the failure of structures in liquefaction and specify effective requalification techniques. In this regard, several most common failure mechanisms of piles during seismic liquefaction such as bending (flexural), buckling instability and dynamic failure of the pile are introduced. Furthermore, the dynamic response commentary is provided by critically reviewing experimental investigations carried out using a shaking table and centrifuge modelling procedures. The emphasis is placed on delineating the concept of seismic design loads and important aspects of the dynamic behaviour of piles in liquefiable soils. In this context, using Winkler foundation approach with the proposed p–y curves and finite-element analyses in conjunction with numerical analysis methods, are outlined. Moreover, the feasibility of successful remediation techniques for earthquake resistance is briefly reviewed in light of the pile behaviour and failure. Finally, practical recommendations for achieving enhanced resistance of the seismic response of pile foundation in liquefiable soil are provided.

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“…Therefore, the dilatancy rate D is the sum of the reversible dilatancy rate D re and the irreversible dilatancy rate D ir . This decomposition of dilatancy has been successfully applied to constitutive models targeting the cyclic behavior of sand, 41,42 being especially effective in simulating cyclic liquefaction behavior 73–75 …”

Section: Model Formulation Unifying the Effects Of Principal Stress Vmentioning

confidence: 99%

Three‐dimensional anisotropic plasticity model for sand subjected to principal stress value change and axes rotation

Xue

Pan

et al. 2020

Num Anal Meth Geomechanics

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A three‐dimensional (3D) anisotropic plasticity model for sand is formulated in this study to provide a constitutive description for both radial and principal stress axes rotation (PSAR) loading‐induced behavior under various conditions with a single set of model parameters. The model has zero elastic range, with plastic loading and flow direction dependent on both current stress and stress rate direction. Fabric tensor is introduced along with its evolution to achieve anisotropic plastic modulus, dilatancy, and flow rule formulations. Increase in plastic modulus under continuous PSAR achieves eventual convergence of strain accumulation. A unique decomposition of dilatancy controls the overall contraction and periodic dilatancy oscillation under PSAR. The performance of the model is first thoroughly evaluated based on drained/undrained, monotonic shear/PSAR tests on Toyoura sand, showing its effectiveness in reproducing the behavior of real sand. Discrete element method numerical test results are then adopted for comprehensive calibration of the model parameters, and then for validation of the model under 3D PSAR in any arbitrary direction. These comparisons highlight the model's capability in simulating the behavior of granular soil under 3D stress paths.

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Finite element model for piles in liquefiable ground

Cited by 75 publications

References 49 publications

Shake‐table investigation of scoured RC pile‐group‐supported bridges in liquefiable and nonliquefiable soils

Shake‐table investigation of scoured RC pile‐group‐supported bridges in liquefiable and nonliquefiable soils

The Dynamic Behaviour of Pile Foundations in Seismically Liquefiable Soils: Failure Mechanisms, Analysis, Re-Qualification

Three‐dimensional anisotropic plasticity model for sand subjected to principal stress value change and axes rotation

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