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Buckling of slender piles in soft soils
Author(s) -
Vogt Norbert,
Vogt Stefan,
Kellner Christian
Publication year - 2009
Publication title -
bautechnik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.224
H-Index - 17
eISSN - 1437-0999
pISSN - 0932-8351
DOI - 10.1002/bate.200910046
Subject(s) - buckling , geotechnical engineering , pile , structural engineering , soil water , shear (geology) , engineering , geology , soil science , petrology
Buckling of piles is prevented by the surrounding soil. Therefore, in sufficiently stiff soils, there is no risk of pile buckling with conventional geometry (L/D ratio). National and international design codes require checks of the safety against buckling for slender piles in soils with undrained shear strengths of c u < 15 kPa or c u < 10 kPa, respectively. In practice, the codes imply that buckling failure does not occur at higher undrained shear strengths. However, using simple calculations, this assumption has been proven to be invalid for slender piles such as micropiles. For the reason, buckling tests on 4 m long micropiles were carried out in soft clay. Based on these results, a new concept with supporting documents for calculating buckling loads was derived, which covers all essential aspects observed in the tests. The proposed model accounts for material non‐linearity, as well as second order effects.