Full Scale Static and Dynamic Lateral Loading of a Single Pile PDF Download

Author: Norazzlina M.Sa'don
Publisher:
ISBN:
Category : Steel piling
Languages : en
Pages :

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Book Description
This study presents the results of full scale field tests on single free head piles embedded in Auckland residual clay. Four hollow steel pipe piles, each with an outside diameter of 273 mm and wall thickness of 9.3 mm were installed at a site in Pinehill, Auckland. Static lateral loads were applied by using hydraulic jack, while dynamic loads were applied using an eccentric mass shaker. The free vibration and snap-back tests were also performed by using instrumented sledgehammer and snap shackle as the quick release mechanism. The primary purpose of the pile testing is to measure the inertial response of piles in Auckland soils and to investigate how the soil stiffness decreases with increasing pile head excitation. The field work initially started with measurement of the small strain stiffness of the soil using wave activated stiffness (WAK) tests and spectral analysis surface waves (SASW) tests. Seismic cone penetration tests (SCPT), low level response of the pile generated by hammer blows and excitation from an eccentric mass shaker were also performed. All of these indicated that a consistent value for the small strain stiffness of the soil. The elastic continuum model (ECM) is the main tool that used for analysis of the pile response. This model has the advantage that it has been extended to enable nonlinear behaviour of the soil around the long elastic pile to be modelled. The approach taken is to interpret the field response in order to estimate the factor by which the small strain stiffness of the soil needs to be reduced to represent the correct stiffness of the cyclic loading loops. In other words, this approach used to evaluate the response of the pile using the design approach outlined in Table 4.1 of EC8 part 5. A soil stiffness reduction factor, Gs / Gs,max of 0.36 was found to give a reasonable prediction for a single pile embedded in Auckland residual clay. This factor agrees very well for the computed values of the pile head load-displacement curve when compared with the static and dynamic full scale field test results performed. Two numerical models, which are OpenSeesPL and Ruaumoko are used to model the single pile subjected to lateral loading. These results were then validated using the full scale field tests data. From a comparison of the predictions and the experimental results of full scale single piles suggest that if the proposed method and model are accurately verified and properly used, then they are capable of producing realistic predictions. A procedure that was particularly developed for preliminary design estimates of a single long pile under the lateral loading is also presented in this thesis.