Experimental investigation of vertical and batter pile groups subjected to dynamic loads
TL;DR: In this article, the dynamic responses of cast in-situ reinforced concrete vertical and batter pile groups constructed in the silty sand have been investigated, and their responses were compared in terms of resonant frequency and peak displacement.
About: This article is published in Soil Dynamics and Earthquake Engineering.The article was published on 2019-01-01. It has received 24 citations till now. The article focuses on the topics: Pile cap & Pile.
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TL;DR: In this paper, experimental and numerical studies are carried out to explore the lateral load and moment resistance capacities of the monopile-friction wheel hybrid foundation in soft-over-stiff soil deposit.
Abstract: Experimental and numerical studies are carried out to explore the lateral load and moment resistance capacities of the monopile-friction wheel hybrid foundation in soft-over-stiff soil deposit. Mod...
9 citations
TL;DR: In this paper, an experimental in-situ campaign of dynamic tests carried out on a full-scale 2'×'2 group of inclined injected micropiles in alluvial soils is described.
8 citations
01 Jan 2019
TL;DR: In this paper, the dynamics of pile groups were examined by integrated physical and computational simulations, and a new theoretical formulation for analysis of multi-modal vibration by accelerance functions was established using the method of sub-structuring.
Abstract: Three dimensional dynamic soil-pile group interaction has been a subject of significant research interest over the past several decades, and remains an active and challenging topic in geotechnical engineering. A variety of dynamic excitation sources may potentially induce instabilities or even failures of pile groups. Employing modern experimental and numerical techniques, the dynamics of pile groups is examined in this study by integrated physical and computational simulations. In the physical phase, fullscale in-situ elastodynamic vibration tests were conducted on a single pile and a 2×2 pile group. Comprehensive site investigations were conducted for obtaining critical soil parameters for use in dynamic analyses. Broadband random excitation was applied to the pile cap and the response of the pile and soil were measured, with the results presented in multiple forms to reveal the dynamic characteristics of the pile-soil system. In the computational phase, the BEM code BEASSI was extended and modified to enable analysis of 3D dynamic pile group problems, and the new code was validated and verified by comparison to reference cases from the literature. A new theoretical formulation for analysis of multi-modal vibration of pile groups by accelerance functions is established using the method of sub-structuring. Various methods for interpreting the numerical results are presented and discussed. Case studies and further calibration of the BEM soil profiles are conducted to optimize the match between the theoretical and experimental accelerance functions. Parametric studies are performed to quantify the influence of the primary factors in the soil-pile system. It is shown that the new 3D disturbed zone continuum models can help improve the accuracy of dynamic soil-pile interaction analysis for pile groups in layered soils. This study therefore helps to advance the fundamental knowledge on
5 citations
TL;DR: In this paper , the authors focused on dynamic lateral behaviour of single batter piles and batter pile groups subjected to machine induced vibrations using 3D finite element (FE) analysis, and the coupled soil-pile system consisting of soil mass, pile/pile groups, and oscillator motor assembly mounted on the top of the pile cap has been modelled using ABAQUS.
Abstract: Batter piles are most commonly used to resist large lateral loads caused by winds, tidal waves and soil pressure as experienced by offshore structures, bridges, and towers in general. The details in literature on the dynamic behaviour of these batter piles based on in-situ tests are limited. The present study focused on dynamic lateral behaviour of single batter piles and batter pile groups subjected to machine induced vibrations using 3D finite element (FE) analysis. The coupled soil-pile system consisting of soil mass, pile/pile groups, and oscillator motor assembly mounted on the top of the pile cap has been modelled using ABAQUS. The soil mass was considered as a half space through appropriate model dimensions and absorbing boundary conditions (using infinite element). A hybrid modelling approach was adopted to obtain the bending moment along the length of the pile. The 3D FE models were developed based on the field tests conducted by the authors on bored cast in-situ batter piles (three batter angles 0°, 10° and 20°) and pile groups (0° and 20°). Dynamic lateral loads were applied on the pile cap in the form of sweep loads for varying force levels of excitation separately. The responses of the 3D FE models were obtained in terms of displacement time histories at mid height of pile cap, displacement, and bending moment profile along the pile length for all the considered cases. This study show that single batter piles (batter angles 10° and 20°) attract the bending moments three times more than single vertical piles.
5 citations
TL;DR: In this paper, the structural behavior of double-pile foundations under cyclic loads was investigated. But, the experimental and analytical results indicated that the pile diameter embedding is adequate for forming the plastic hinge at the ends of both vertical and battered CFT piles.
4 citations
References
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Journal Article•
225 citations
TL;DR: In this article, a general formulation for the dynamic response analysis of piles and pile groups in a layered halfspace is presented, and a limited number of representative results on the dynamic stiffnesses and seismic response of pile groups are presented.
164 citations
TL;DR: In this article, a boundary element formulation for the dynamic analysis of axially and laterally loaded single piles and pile groups is presented, where the piles are represented by compressible beam-column elements and the soil as a hysteretic elastic half-space.
Abstract: A boundary element formulation for the dynamic analysis of axially and laterally loaded single piles and pile groups is presented. The piles are represented by compressible beam-column elements and the soil as a hysteretic elastic half-space. The governing equations of motion for the pile domain have been solved exactly for distributed periodic loading intensities. These solutions are then coupled with a numerical solution for the motion of the soil domain by satisfying equilibrium and compatibility at the pile-soil interface. The results obtained from the analysis compare favourably with those from alternative analyses, e.g. finite element, but at greatly reduced computational costs.
130 citations
TL;DR: In this article, a case study of the effect of lateral spreading on the piled foundations of the Landing Road Bridge, Whakatane, New Zealand, during the ML 6·3, 1987 Edgecumbe earthquake was presented.
Abstract: A case study is presented of the effect of lateral spreading on the piled foundations of the Landing Road Bridge, Whakatane, New Zealand, during the ML 6·3, 1987 Edgecumbe earthquake. Trenching at two piers on the floodplain of the left bank revealed slip surfaces in the 1·5 m thick non-liquefied crustal layer, consistent with passive failure as the buried piers and raked piles resisted its displacement towards the river channel. The passive force on the buried portion of the slab piers is estimated at 850–1000 kN per pier, compared with roughly 50 kN in drag forces between the underlying liquefied sand and the set of eight, 400 mm square raked piles per pier. The collapse load of the foundation system is estimated to be about 1200 kN. Thus the force imposed by the non-liquefied crust was close to the ultimate capacity of the foundation. Our main conclusion is that the chief threat to piled foundations from lateral spreading comes from loads imposed by the non-liquefied crust, not from the drag forces of ...
110 citations
TL;DR: In this article, simplified analytical models for the lateral harmonic response of single piles and pile groups in layered soil were developed for the impact of pile-to-soil interplay, represented by a dynamic Winkler formulation based on frequency-dependent springs and dashpots.
Abstract: Simplified analytical models are developed for the lateral harmonic response of single piles and pile groups in layered soil. Pile-to-soil interplay is represented by a dynamic Winkler formulation based on frequency-dependent springs and dashpots. For pile-to-pile interaction, the wave field originating from each oscillating (“source”) pile and the diffraction of this field by the adjacent (“receiver”) piles are considered. The response of single piles and pile pairs is evaluated both numerically (through a transfer-matrix formulation) and analytically (introducing an efficient virtual-work approximation). Closed-form solutions are obtained: (1) for the impedance of single piles; (2) for the dynamic interaction factors between two piles; and (3) for the “additional” internal forces (“distress”) developing in grouped piles because of pile-to-pile interaction, a phenomenon frequently ignored in current methods of analysis. Both swaying and rocking vibrational modes are considered. The effect of pile length ...
108 citations