自升式平台踩脚印失稳机理大变形有限元分析

Large Deformation Finite Element Analysis of the Failure Mechanism of Jack-up's Reinstallation near Footprints

自升式平台桩靴踩脚印失稳相关研究较少,且多为实验研究,土体的流动破坏模式和桩靴失稳机制尚不十分清楚。运用CEL有限元方法来模拟桩靴贯入均匀土体的过程,选择出最合适的网格密度,在此基础上模拟桩靴在旧桩坑附近的二次插桩过程,分析了旧桩坑的几何形状(包括深度、坡度和直径)、二次插桩偏心距对桩靴基础二次插桩稳定性的影响规律,考察桩靴的最大峰值水平力Hmax、最大峰值弯矩Mmax,并联合土体的流动破坏机制分析了桩靴踩脚印失稳机理。

Most of the existing researches on the interaction between spudcans and footprints are obtained by model tests. The failure mechanisms during reinstallation are still not very clear. This study firstly carried out Coupled Eulerian- Language（ CEL） analyses to simulate processes of spudcan installed in homogeneous soils. The most suitable mesh density was selected. After that reinstallation processes of spudcans close to existing footprints were simulated. Effects of footprint geometry（ depth,slope angle and diameter） and reinstallation offset on the developing behaviors of vertical resistance,horizontal resistance and moment acting on spudcan. The soil flow mechanisms during a spudcan reinstallation near an existing footprint were discussed.