砂质海床中锚板基础水平振动动力特性研究

Horizontal vibration of a deeply buried plate anchor in sandy seabed

基于埋置在耦合海水–海床半空间中刚性、无重量圆盘基础的水平振动动力阻抗[1],简单讨论了海洋工程中常用的承受竖向拉力的、有自重的锚板基础在水平波浪动荷载下的振动情况。给出了计算深埋锚板基础在发生共振时的共振频率和放大系数的简化计算公式。最后通过采用实际的海床砂土参数及锚板参数,得出了只要锚板的厚径比满足一定的要求,深埋锚板基础一般不会发生共振的结论。对于真实的深埋锚板基础,这个厚径比要求一般是较容易满足的。此外,锚板水平位移对低频海洋波浪水平荷载的频率变化并不敏感,最大水平位移发生在频率为0即静载情况下。本文结论对于理解海洋工程中锚板基础在水平波浪荷载作用下的振动特性有所帮助。

Based on the dynamic impedance of a massless rigid disc buried in a coupled seawater-seabed half-space（He and Wang, 2013）, the horizontal vibration of a widely used deeply buried plate anchor is studied, which is subjected to a constant vertical pull force and with self-weight, under harmonic horizontal wave loads. Simplified formulas to calculate the resonance frequency and magnification factor are given. By using parameters of a real seabed and plate anchors, it is found that the resonance of the deeply buried plate anchor can be avoided if the thickness to radius ratio of the anchor satisfies some requests. For real plate anchors, it is very easy to satisfy the requests. Besides, the horizontal displacement of the deeply buried plate anchor seems to be independent of the frequencies of the wave loads, and the largest horizontal displacement occurs when the wave load frequency is 0. The results of this study will be helpful for understanding the horizontal vibration characters of the widely used deep sea plate anchors.