插拔桩靴对临近桩靴承载力的影响研究

自升式钻井船桩靴的插拔过程将会对临近井口平台的桩靴基础产生不利影响。开展了室内模型试验研究，将试验结果与理论分析结果相结合，得到了桩靴插拔的影响范围及影响范围内土体强度的变化规律，并推导了桩靴插拔影响区内临近桩靴承载力的计算方法，与模型试验结果进行了对比验证。研究表明，桩靴插拔后砂土相对密实度降低，其降低程度随距桩靴距离的增加而逐渐减小，影响范围约为1倍桩靴直径。受桩靴插拔影响，临近桩靴的承载力下降，降低比例随两桩靴相对间距的增大而减小，随桩靴相对插深的增加而增加。当两桩靴相对间距大于2倍插拔桩靴直径时，可认为桩靴插拔对临近桩靴基础承载力无影响。

Experimental study of the effect of spudcan penetration and extraction on bearing capacity of an adjacent spudcan

The penetration and extraction process of the spudcan of jack-up drilling platform may adversely affect the spudcan of the adjacent wellhead platform. The effect of soil strength and the influenced region after the penetration and extraction of spudcan were examined by performing the model tests and the theoretical analysis. A theoretical method for calculating the bearing capacity of an adjacent spudcan within the influenced region of the spudcan penetration and extraction is developed and compared with the model test results. The results demonstrate that, the relative compaction of sand is reduced after spudcan penetration and extraction, and the rate of reduction gradually decreases with increasing distance to the spudcan. The influenced region of the surrounding soil is approximately one times the diameter of the spudcan. The bearing capacity of adjacent spudcan is reduced due to the spudcan penetration and extraction, and the reduction rate of the bearing capacity decreases as the relative distance between two spudcans increases and increases as the relative penetration depth between two spudcans increases. When the relative distance between two spudcans is greater than 2 times the diameter of the spudcan, it can be considered that the spudcan penetration and extraction have no effect on the bearing capacity of the adjacent spudcan foundation.