巨浪冲蚀威胁下的海底管道仿生草防护技术

Bionic Grass Protection Technology for Submarine Pipelines Under the Threat of Huge Wave Erosion

仿生草防护技术是一种通过降低海底管道附近水流的流速,促进沉积物颗粒在海底管道附近进行沉降淤积以防止冲刷发展的防护技术。波生流是近岸地区的重要水动力现象,直接影响海岸地貌演变与输沙过程。通过多组物理模型试验模拟了波浪作用于不同底质条件下仿生草对海底管道冲刷的防护作用以及不同的仿生草布设方式对其防护效果的影响,并对其作用机理进行了初步的分析研究。结合仿生草在平湖海管中的实际应用,证明了仿生草对悬空管道的防护效果明显。波浪在近岸区可能产生较强底流,仿生草技术通过阻尼作用对于砂质海床具有明显的防冲刷效果,但对于粉质海床效果略差,这是由于底质不同造成的。仿生草布设方式对其防护效果至关重要,主要是海底管道两侧的仿生草发挥了防护作用。建议根据具体情况将仿生草技术结合传统方法进行作业实施,以取得更好的效果。

The bionic grass protection technology is a kind of technology that is used to prevent the development of scour through reducing the speed of water flows and then promoting the deposition of sediment particles around the submarine pipelines.Wave-induced current is an important hydrodynamic phenomenon in the coastal waters and can directly influence the coastal geomorphic evolution and the sediment transport process.Under the conditions that wave acts on different seabed substrates,the protective effect of bionic grass on submarine pipeline scour and the influence of different layout of bionic grass on the protective effect are simulated through multiple sets of physical model tests.Also,the mechanisms of the actions are studied preliminarily.Combining with the practical application of bionic grass technology in the Pinghu oil field,the protective effect of the bionic grass on the suspended submarine pipelines is proved to be obvious.However,it is argued that the waves in the coastal waters may produce stronger bottom currents so that the scour-prevention effect of the bionic grass on the submarine pipelines by damping could be better in the sandy seabed areas than in the silty seabed areas,reflecting that the scour-prevention effect of the bionic grass is related to the seabed substrates.The layout of bionic grass plays also an important role to the scour-prevention effect of the bionic grass.It has been found that the bionic grass which is laid on both sides of the submarine pipeline plays the role of protection.It is therefore suggested that in order to obtain better protective effect,the bionic grass technology should be operated in combination with the traditional methods in accordance with specific conditions.