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Buckling of Short End-Bearing Piles in ClayEbenhardt, David, Stener, Jonas January 2022 (has links)
Structural design of piles with respect to buckling in Sweden is commonlymade in accordance with the calculation model from the Commission ofPile Research, PKR. A prerequisite for this model is that the elasticbuckling length of the pile is shorter than the physical length. For shortpiles this assumption might not be valid, meaning that anotherappropriate calculation model may be used instead. This situation occurswhen designing end-bearing piles in typical geological conditions foreastern Sweden, consisting of soft clay and shallow bedrock.This thesis compared the PKR-model with alternative models for thedesign of short piles. One of the alternate calculation models was a finiteelement model where Winkler springs represented the soil. It was used tosimulate cases with various diameters and undrained shear strengths.Furthermore, the results using the PKR- and FEM-model was comparedto calculations according to Eurocode 3 considering the pile as a freestandingcolumn. By the help of the FEM-model, a method to considergreater initial deflections in the Eurocode 3-model was also developed.In conclusion, the PKR-model was non-conservative for some of thetested cases. With some precautions taken for those cases, the model wasvalid to use for elastic buckling lengths up to two times the physicallength of the pile. The results from the Eurocode 3-model were bothconservative and non-conservative depending on the pile- and soilconditions. It was seen that the analytical models were not comparablesince they handle prerequisites and design assumptions in different ways.A sensitivity analysis was also made which resulted in suggestions forfurther research on the topic.
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