板翼动力锚沉贯深度模型试验研究

板翼动力锚是依靠自重完成安装并靠自重和海床土的抗力来锚固的新型动力锚。板翼动力锚高速(15~25 m/s)贯入地基过程中涉及到高应变率、流固耦合、土体软化和大变形等难题,模型试验可避免上述计算困难,能直接得出不同的贯入速度所对应的沉贯深度。本文首先推导了模型相似关系,然后在常规重力条件下,进行了两组26个工况的板翼动力锚在均质黏土中动力安装过程的模型试验,根据试验结果确定了率效应参数的取值范围,并研究了每一项受力对沉贯深度的影响。最后提出了在均质黏土中预测板翼动力锚沉贯深度的经验公式。

Model tests on the penetration depth of gravity installed plate anchors

Gravity installed plate anchors are newly developed dynamic anchors installed through self-weight. The uplift capacity is provided by the anchors self-weight and the soil resistance. The installation process is a high-speed motion (15~25 m/s) which involves computational problems such as the fluid-solid interaction, the stain softening and strain-rate behavior of soil and large deformation of soil. In order to avoid the problems mentioned above, the similitude requirements in normal gravity field are discussed firstly, then the results from two groups of penetrating model tests are presented to study the relation between penetration velocity and embedment depth in uniform clay. According to the test results, the ranges of the parameter characterizing the strain-rate effect are obtained. The effects of each part in the motion equation on the embedment depth are also discussed. An empirical equation is finally presented to estimate the embedment depth in uniform clay based on the anchor energy.