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Pile Foundations (pile + foundation)

Distribution by Scientific Domains

Engineering	100%

Selected Abstracts

A model for the 3D kinematic interaction analysis of pile groups in layered soils

EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 11 2009
Francesca Dezi
Abstract The paper presents a numerical model for the analysis of the soil,structure kinematic interaction of single piles and pile groups embedded in layered soil deposits during seismic actions. A finite element model is considered for the pile group and the soil is assumed to be a Winkler-type medium. The pile,soil,pile interaction and the radiation problem are accounted for by means of elastodynamic Green's functions. Condensation of the problem permits a consistent and straightforward derivation of both the impedance functions and the foundation input motion, which are necessary to perform the inertial soil,structure interaction analyses. The model proposed allows calculating the internal forces induced by soil,pile and pile-to-pile interactions. Comparisons with data available in literature are made to study the convergence and validate the model. An application to a realistic pile foundation is given to demonstrate the potential of the model to catch the dynamic behaviour of the soil,foundation system and the stress resultants in each pile. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Lateral load distributions on grouped piles from dynamic pile-to-pile interaction factors

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 2 2009
Der-Wen Chang
Abstract The load distributions of the grouped piles under lateral loads acting from one side of the pile cap could be approximately modeled using the elasticity equations with the assumptions that the underground structure is rigid enough to sustain the loads, and only small deformations of the soils are yielded. Variations of the soil,pile interactions along the depths are therefore negligible for simplicity. This paper presents the analytical modeling using the dynamic pile-to-pile interaction factors for 2,×,2 and 2,×,3 grouped piles. The results were found comparative with the experimental and numerical results of other studies. Similar to others' findings, it was shown that the leading pile could carry more static loads than the trailing pile does. For the piles in the perpendicular direction with the static load, the loads would distribute symmetrically with the centerline whereas the middle pile always sustains the smallest load. For steady-state loads with operating frequencies up to 30 Hz, the pile load distributions would vary significantly with the frequencies. It is interesting to know that designing the pile foundation needs to be cautioned for steady-state vibrations as they are a problem of machine foundation. However, for transient loads or any harmonic loads acting upon relatively higher frequencies, the pile loads could be regarded as uniformly distributed. It is hoped that the numerical results of this paper will be helpful in the design practice of pile foundation. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Response simulation and seismic assessment of highway overcrossings

EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 9 2010
Anastasios Kotsoglou
Abstract Interaction of bridge structures with the adjacent embankment fills and pile foundations is generally responsible for response modification of the system to strong ground excitations, to a degree that depends on soil compliance, support conditions, and soil mass mobilized in dynamic response. This paper presents a general modeling and assessment procedure specifically targeted for simulation of the dynamic response of short bridges such as highway overcrossings, where the embankment soil,structure interaction is the most prevalent. From previous studies it has been shown that in this type of interaction, seismic displacement demands are magnified in the critical bridge components such as the central piers. This issue is of particular relevance not only in new design but also in the assessment of the existing infrastructure. Among a wide range of issues relevant to soil,structure interaction, typical highway overcrossings that have flexible abutments supported on earth embankments were investigated extensively in the paper. Simulation procedures are proposed for consideration of bridge-embankment interaction effects in practical analysis of these structures for estimation of their seismic performance. Results are extrapolated after extensive parametric studies and are used to extract ready-to-use, general, and parameterized capacity curves for a wide range of possible material properties and geometric characteristics of the bridge-embankment assembly. Using two instrumented highway overpasses as benchmark examples, the capacity curves estimated using the proposed practical procedures are correlated successfully with the results of explicit incremental dynamic analysis, verifying the applicability of the simple tools developed herein, in seismic assessment of existing short bridges. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Three-dimensional finite element analysis of the interaction between tunneling and pile foundations

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 3 2002
H. Mroueh
Abstract This paper concerns analysis of the impact of construction of urban tunnels on adjacent pile foundations. It is carried out using an elastoplastic three-dimensional finite element modelling. Numerical simulations are performed in two stages, which concern, respectively, the application of the pile axial loading and the construction of the tunnel in presence of the pile foundations. Analysis is carried out for both single piles and groups of piles. Results of numerical simulations show that tunneling induces significant internal forces in adjacent piles. The distribution of internal forces depends mainly on the position of the pile tip regarding the tunnel horizontal axis and the distance of the pile axis from the centre of the tunnel. Analysis of the interaction between tunneling and a group of piles reveals a positive group effect with a high reduction of the internal forces in rear piles. Copyright © 2002 John Wiley & Sons, Ltd. [source]