埕北海域海底管线冲刷稳定性研究

根据埕北海域水下三角洲的工程地质条件和水动力条件，分析海底管线在两种铺设方式情况下的冲刷稳定性。第一种为埋置在一定土层深度处的管线：根据整个埕北海域海底长期冲淤变化规律，利用１９９２～１９９６ 年的实测水深资料得出的冲刷速率，推算出管线被冲出泥面所需的时间。第二种为裸露在海底的管线：根据海流对管线周围沉积物产生冲刷效应，冲刷达到一定程度时处于平衡状态，认为此状态下，海流在该点产生的剪切力等于形成可冲蚀海床沉积物的临界牵引力，据此计算出在管线周围冲刷的最大深度

Study on Stability of Submarine Pipeline in Chengbei Area

With the development of marine petroleum, the number of submarine pipelines is increasing year after year, and the stability of the pipelines is of importance. This paper studies the stability of scour of pipelines laid in two ways, according to the geotechnical condition and condition hydrodynamic of the Chenbei area. In the first laying method, pipelines are laid under certain depths of soil. The time can be calculated when the pipelines were exposed on the seabed by the speeds of scour obtained from 1992~1996 water depth data. In the second method, the pipeline is exposed on the bottom. If the water velocity in the scour hole is greater than the free stream velocity, erosion may occur, and the limit of scour can be obtained by estimating the maximum scour depth under the off shore pipelines caused by currents.