In the article, the bearing capacity and load transfer mechanism of super-long bored pile with large length/diameter ratio in soft soil are discussed, based on the static loading tests and axial force tests on the peculiar super-long bored piles in Wenzhou World Trade Center, where the length/diameter ratio is as large as 109.1. The study gains the following conclusions. a) The load-settlement curves are changing slowly and the ultimate load should be established according to the pile tip settlement. b) The distribution of lateral friction resistance looks like 'R' shape; pile-soil relative displacement decreases with the increase of pile depth; end-bearing resistance become working when the load exceeds or comes to the designed load, this indicates that lateral friction resistance and end-bearing resistance play asynchronously. c) In the upper part of pile, load transfer slowly because of the existence of upper soft soil. d) Under the designed load, the bearing capacity of the deep part of pile doesn't be exerted fully. In this condition, the pile can be treated as friction pile. This also indicates that super-long bored pile has the effective length which means length/diameter ratio cannot be too large, that must be taken into consideration during design process. These results are important to the theoretical research and technical application of large length/diameter ratio pile embedded in deep soft soil.
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