作用于透空圆环墩柱的浅水波绕射波浪力与波浪渗流力

透空结构具有降低海浪作用的功效。该文基于椭圆余弦波一阶分量的浅水波理论和Biot渗流固结理论,分别推导了浅水区固立于可渗透弹性海床上透空圆环墩柱的绕射波浪压力以及由波浪所致海床内渗流压力的数学解,并据此对墩柱所受绕射波浪力与力矩以及渗流浮托力与倾覆力矩进行了实算。结果表明,海况条件和结构参数的变化对波浪所引起的各种载荷存在不同的影响效应,波浪渗流力与波浪直接作用可能具有相同量级。圆环柱外表面的可渗透性对浅水波的直接波浪作用具有明显的减弱效应,而对渗流倾覆力矩也具有一定的减弱效应。此外,圆环墩柱内外柱半径比存在优化取值,以使墩柱达到减载和稳定的双重效果。与Airy波浪理论计算结果相比,浅水波理论的结果能有效反映水波非线性因素的可能影响。

Shallow Water Wave-induced Diffracted Wave Forces and Wave Seepage Forces on Porous Vertical Circular Cylinder

Porous structures have the property of diminishing wave loads. Based on first order cnoidal wave theory and Biot consolidation theory, the mathematical solutions are derived for shallow water wave diffracted pressure and wave induced seepage pressure on a porous vertical circular cylinder resting on porous elastic seabed in shallow water, and direct wave force and moment and wave induced uplift force and overturn moment on the circular cylinder are correspondingly evaluated. The result shows that the variation of ocean condition and structure parameter have different effects on various wave loads， the magnitude of wave-induced seepage loads may have same order of horizontal wave loads, and the permeability of the cylinder surface will lead an obvious reduction in direct wave effects on cylinder and certain reduction in seepage overturn moment on the bottom of cylinder. Furthermore, the suitable choice of the ratio of the cylinders inside diameter to outside diameter may lead effects of both diminishing wave loads and ensuring stability of circular cylinder. Compared with the results from Airy wave theory, the wave load prediction values from shallow water wave theories can reflect wave nonlinearity effects.