Bearing behaviors of super-long single pile in soft soil areas
ZHANG Qian1, LI Shu-cai1, ZHANG Qian-qing1, 2, LI Li-ping1, ZHOU Zong-qing1
1. Research Center of Geotechnical and Structural Engineering, Shandong University, Jinan 250061, China; 2. State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining & Technology, Xuzhou 221116, China
Abstract：The static load test results of super-long bored piles in soft soil areas show that the curing effect of slurry on mud cake around pile shaft and the compaction and curing effect of slurry on the sediment and bearing layer can improve the bearing capacity of single pile. Under the working load, the compression of pile shaft accounts for more than 90% of pile top settlement, and the percentage of super-long pile top settlement caused by the compression of pile shaft is over 70% under the maximum load. Therefore, the influence of pile shaft compression on the pile head settlement should not be ignored in the design of super-long piles. Moreover, it can be concluded that the skin friction softening occurs in the upper soil layers of the super-long piles, whereas the skin friction in the deeper soil layers can not be fully mobilized. The traditional methods for the bearing capacity calculation of supper-long piles will have a certain error in the actual bearing capacity.
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