启东某场地自升式平台插桩可行性试验研究

桩靴接触应力是影响插桩深度的主要因素之一，桩靴的锥尖型式可能会影响接触应力的大小及分布。以江苏省启东市某插桩试验项目为例，针对不同的桩靴端部型式基于桩靴接触应力现场实测数据，分别采用国内外规范方法及数值计算方法对插桩深度开展预测分析，揭示桩靴端部型式对插桩深度的影响规律。结果表明：在插桩过程中不同锥端类型桩靴的接触应力呈现出中央大周边小的分布特征，表明现场桩靴为柔性结构类型；采用不考虑桩靴端部形状的规范方法进行桩靴插深预测，得出的预测结果同现场实测结果基本吻合；采用小变形有限元数值方法进行插深预测也可以得出令人满意的结果，研究结果可为类似工程实践提供参考。

In-situ experimental study on spudcan penetration depth of jack-up platform in a site in Qidong city

The distribution form of contact stress between the bottom of pile shoe and foundation has a significant effect on the penetration depth of pile, and the magnitude and distribution form of contact stress are associated with the tapered tip type of the pile shoe. Therefore, taking the pile penetration project in Qidong, Jiangsu province, as an example, the relationship between the tapered tip type of pile shoe and the penetration depth of pile has been discussed. Based on the field monitoring data of contact stress under different pile shoes, the penetration depth of pile has been calculated by empirical formulae recommended in the engineering specifications at home and abroad and numerical simulation method, respectively. The results demonstrate that the contact stress in the middle area is greater than that at the edge of the pile shoe with different cone end forms. The characteristic of stress distribution is similar to that of flexible plates. When the penetration depth of pile shoe is predicted according to the empirical formulae recommended in the engineering specifications, the effect of the shape of pile shoe on penetration depth can be ignored, and the calculated value is basically consistent with the field measured one. The penetration depth of pile predicted by small deformation finite element numerical method is satisfactory. The conclusions of this paper can provide reference for similar engineering practice.