DBPapers
DOI: 10.5593/SGEM2014/B12/S2.127

TIME DEPENDENT FACTORS IN DRIVEN PILE CAPACITY CONTROL

J. Rybak, T. Zyrek
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-08-7 / ISSN 1314-2704, June 19-25, 2014, Book 1, Vol. 2, 995-1002 pp

ABSTRACT
Load tests (capacity tests) belong to the set of indispensable control procedures which verify the design before the execution of pile foundations. Organizational difficulties may however arise from the necessity to adjust the building site only in order to install the piles in the testing site. That disadvantage is crucial especially when the number of piles is small and the costs of re-adjustment of the building site or the standstill in the works caused by the testing methodology are irrelevantly expensive in comparison with the contract value. The conditions presented above form the basis for the undertaken attempt at the analysis of the influence of the time - elapsing between the driven pile installation and the static load test – on the test results. Such an influence reported by Skov [7] and Svinkin [8] is significant, especially in the case of stiff cohesive soils where so called soil “setup effect” accompanied by dissipation of pore pressure at the soil pile interface zone may last in terms of years. The detailed analysis of setup in sands is a subject of studies by Jardine [2] and König [3]. Bearing in mind the applied piling technology and the soil conditions, it is necessary to define the minimal time span between the piling and the beginning of the tests. At the same time, the pressure from the contractors often causes the control procedures to begin and finish before that time.

Keywords: static load test, setup, driven pile, sheet pile, ultimate capacity