Drag forces caused by submarine glide block or out-runner block impact on suspended (free-span) pipelines
Drag forces caused by submarine glide block or out-runner block impact on suspended (free-span) pipelines
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DOI：
10.1016/j.oceaneng.2012.03.016
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发表时间：
2012-06
影响因子：
5
通讯作者：
A. Zakeri;B. Hawlader;Ken Chi
中科院分区：
文献类型：
--
作者：
A. Zakeri;B. Hawlader;Ken Chi
介绍了一系列物理实验的结果，以量化的阻力所造成的海底管道上的滑动块或out-runner块冲击垂直于管轴。实验是在浸没条件下的土工离心机中进行的，离心力为地球重力的30倍（即N=30），并在稳态条件和匀速下模拟撞击情况。土块（原型约4.5米高）由不排水剪切强度在4至8 kPa之间的高岭土制成。模型管直径分别为6.35和9.52 mm（原型管直径分别为0.19和0.29 m）。撞击速度在0.04 ~ 1.3m/s之间。管道中心线位于块的中间高度。剪切应变率，定义为冲击速度与管道直径的比值。剪切应变速率范围为约4至137秒的倒数。因此，测试结果适用于广泛的现场情况。提出了一种基于离心机试验结果估算海底管道滑移或外滑块撞击阻力的方法。
The results of a series of physical experiments to quantify the drag force on a submarine pipeline caused by a glide block or an out-runner block impact normal to the pipe axis are presented. The experiments were conducted in a geotechnical centrifuge under submerged conditions at a centrifugal force of 30 times the Earth's gravity (i.e. N=30) and simulated impact situations under steady state conditions and uniform velocities. The soil blocks (approximately 4.5m high in prototype terms) were made of kaolin clay with undrained shear strengths between 4 and 8kPa. The model pipes were 6.35 and 9.52mm in diameter (0.19 and 0.29m in prototype terms). The impact velocities ranged between 0.04 and 1.3m/s. The pipe centerline was at mid-height of the block. The shear strain rates, defined as the ratio of impact velocity to pipe diameter. The shear strain rates ranged from about 4 to 137 reciprocal seconds. Hence, the test results are applicable to a wide range of field situations. A method is presented for estimating glide or out-runner block impact drag force on submarine pipelines based on the results of the centrifuge experiments.