摘要
东营埕岛海域广泛分布"铁板砂-黏土"地层,自升式平台的桩靴基础在这种复杂土层中安装时易发生穿刺失稳。为研究此类问题,进行了离心机模型试验,量测"铁板砂-黏土"中桩靴贯入阻力随深度的变化。针对铁板砂层中峰值阻力的幅值及出现深度,讨论了ISO规范和两种代表性预测方法的适用性,发现可以将铁板砂层视为不排水条件下的强黏土层,采用针对"强黏土-弱黏土"地层的预测方法估计峰值贯入阻力。
The"hard crust layer-clay"layered soil is spread widely in shallow waters near Chengdao,Dongying.When they are installed in such stratigraphy,the spudcan footings of jack-up rigs are vulnerable to punch-through failure.A number of centrifuge tests were conducted to explore the penetration resistance profile of spudcans in hard crust layer overlying clay.The approaches recommended in the ISO guidelines and other two representative approaches are compared,in terms of the magnitude of peak resistance and its corresponding depth.It is found that hard silty sand layer can be regarded as a strong clay layer under undrained conditions,then the peak resistance may be estimated through previous approaches for"stiff-over-soft"clays.
引文
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