黏土中大直径钢圆筒在桩靴贯入时的稳定性研究

STUDY ON STABILITY OF LARGE-DIAMETER STEEL CYLINDER DURING SPUDCAN PENETRATION

  • 摘要: 某在建水下生产系统附近有自升式平台的频繁桩靴插拔作业,采用了大直径薄壁钢圆筒作为水下生产系统的保护结构,因此钢圆筒在自升式平台桩靴插拔过程中的受力与变形备受关注。开展了离心模型试验,揭示了桩靴贯入过程导致的钢圆筒受力与变形规律;进而应用经离心试验验证的耦合欧拉与拉格朗日数值模拟方法,开展了筒-靴不同相对位置工况下,桩靴贯入对钢圆筒稳定性的影响分析。结果表明:桩靴贯入导致的筒壁附加应力及位移随筒-靴间距的增加而衰减,其衰减程度随筒靴间距的增加而减小,且由于筒靴间距的不同,钢圆筒对应存在两种受力模式。筒靴间距为2倍桩靴直径时,筒身附加应力可达110 MPa,表明桩靴对钢圆筒的影响距离可达2倍桩靴直径以上。

     

    Abstract: A large-diameter thin-walled steel cylinder is used as the protective structure of a submarine production system. Near the production system, there is a jack-up rig with frequent operations of spudcan penetration. Therefore, the stress and deformation of the steel cylinder during spudcan penetration have attracted many attentions. Centrifuge model tests are carried out to investigate the behaviour of steel cylinders caused by spudcan penetration. Then, CEL method verified by a centrifuge test is used to analyze the influence of spudcan penetration on the stability of steel cylinders under different spudcan-cylinder clearances. The results show that the additional stress and displacement of the cylinder caused by the spudcan penetration decrease with the increase of the spudcan-cylinder clearance. And the reduction degree decreases with the increase of the spudcan-cylinder clearance. Due to the different spudcan-cylinder clearances, there are two stress modes for the steel cylinder. When the clearance is twice the diameter of the spudcan, the additional stress of cylinder can reach 110 MPa, indicating that the affected distance of the spudcan penetration on cylinder can reach more than 2 times the spudcan diameter.

     

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