130,436 research outputs found
Full-scale lateral impact load test of a 3-pile group
No full textThis paper presents real scale field tests of a group of three steel pipe piles subjected to horizontal impact load.
The piles are vibro-driven in marine soft clay, with a L-shape plan layout and free head. The instrumentation of
piles consists of an unconventional technique for field tests in marine environment and includes accelerometers
at the head of each pile and strain gauges and pore pressure gauges along the fully instrumented corner pile.
Some of the results collected as part of this experimental programme are presented, i.e. time histories of strains
and accelerations. The dynamic behaviour of the complex soil-water-pile system is discussed in terms of natural
frequencies, damping and mode shapes of the first and second pile bending modes. Finally, a 3-D finite element
model of the system, calibrated with the experimental results, is presented
Lateral impact loading and snap-back testing to estimate linear and nonlinear dynamic response of near-shore piles
No full textLinear and Nonlinear Dynamic Response of Piles in Soft Marine Clay
No full textThis paper presents the results of free vibration tests carried out at different load levels on a system of three near-shore steel pipe
piles vibro-driven into soft marine clay. Piles are arranged in an L-shaped horizontal layout and are free at the head. The instrumentation
consists of strain gauges placed at selected levels along the shaft of the loaded pile and accelerometers at the head of the receiver piles. The
aim of this experiment is to analyze the dynamic soil–water–pile and pile-to-pile interaction and to investigate the development of nonlinearities
at increasing load levels. The results of experimental modal analyses, in terms of natural frequencies and damping ratios of
the system, are presented and the complex dynamic behavior of the vibrating soil–water–pile system and the pile-to-pile interaction are
discussed. For a better reliability assessment of the system response in the range of linear behavior, the results of free vibration tests at
the lowest level of the applied loads are compared with those obtained from impact load tests
Dynamic Characterization of Open-ended Pipe Piles in Marine Environment
No full textThis chapter is focused on the experimental investigations that can be carried out to dynamically characterize open-ended pipe piles in marine environment. Different test typologies, such as impact load test, free vibration test, forced vibration test, and ambient vibration test, are presented and described with the purpose to provide the right tools to analyze the dynamic behavior, at both small and large strains, of single piles or a system of piles. The appropriate instrumentation, with the suitable protection from marine environment and pile driving installation procedure, is also illustrated. Furthermore, the most common signal processing techniques useful for handling the experimental raw data are addressed together with the analysis techniques for the evaluation of the modal parameters: natural frequencies, damping ratios, and mode shapes. Finally, a part of the experimental campaign carried out by the authors on near-shore open-ended pipe piles is reported as a case study
Experimental study of near-shore pile-to-pile interaction
No full textThis paper presents the results of lateral impact load field tests carried out on a system of three steel
pipe piles vibro-driven into soft clay in a near-shore marine environment, with the aim of evaluating
the pile–soil–pile dynamic interaction. Piles are arranged in an ‘‘L’’ shaped horizontal layout and are
instrumented with accelerometers at their free heads. The obtained results show the complex dynamic
behaviour at very small strain of the vibrating soil–water–piles system. The role of different type of
waves in the pile to pile interaction is investigated by analyzing the results in the time and frequency
domains and by means of a time–frequency analysis. The effects of the pile spacing and input direction
on these interaction mechanisms are also presented. Finally, important dynamic parameters of the soil,
such as the velocities of the shear waves and surface waves (Scholte waves) of the upper soil are
directly estimated from the time delays between signals recorded at the pile heads
Dynamic response of a near-shore pile to lateral impact load
No full textThis paper presents the results of lateral impact load field tests conducted on a near-shore steel pipe
pile vibro-driven into soft marine clay. Two series of tests are carried out, the first 1 week and the
second 10 weeks after the vibro-driving. The pile is instrumented with an unconventional technique for
field tests in marine environment which includes an accelerometer at the pile head, strain gauges and
pore pressure transducers along the pile. Instruments are properly protected from marine environment
and pile driving installation method. Tests are aimed at investigating the dynamic soil-water-pile
interaction and determining the dynamic characteristics of the whole system at very small strain.
The obtained results show the complex dynamic behaviour of the vibrating soil-water-pile system in
terms of natural frequencies, damping and mode shapes. The variation in the dynamic behaviour in
time, due to reconsolidation of soil subsequent to vibro-driving is also discussed. Furthermore, the
horizontal dynamic impedance function of the whole system is derived from the experimental data
over a wide frequency range and compared with that obtained from a numerical soil–pile
interaction model
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