中文摘要：

斜坡海床上不同管道位置会引起不同冲刷,会对海床形态演变产生影响,因此管道周围的海床床面变化对于管道的铺设极为重要。在波浪水槽中,采用中值粒径为0.38mm原型沙铺设1∶15坡度的底床模型进行试验,测量波浪作用下不同管道位置的床面形态。通过测量和计算管后冲刷坑深度、沙坝和沙坑到坡脚的距离,分析管道位置对沙质斜坡海床上床面形态演变的影响规律。试验结果表明,管道存在使波浪在破碎点附近波高增加,管道搁置在相对水深比Δ=0.36处与无管条件相比,波高增加幅度接近10%;随着相对水深比Δ减小,管后冲刷坑最大值先减小后增大,管道搁置在Δ=0.47处,管后冲刷坑最大值约为0.2倍管径,对床面形态影响最小;随着管道距离破碎点越近,形成的沙坝位置向岸方向移动。

英文摘要：

Different pipeline positions on a sloped seabed will cause different types of scour,affecting the evolution of seabed form.The change in seabed surface around the pipeline is extremely important to pipeline laying.In this experiment,a seabed model at the slope of 1：15 was laid with prototype sand（median diameter：0.38mm）in a wave flume to measure the bed form under wave condition at different pipeline positions.Through measurement and calculation of the scour pit depth and the distance from sandbar and sand pit to the slope toe,an analysis was conducted on the influence of pipeline position on the change in bed form on the sloped sand seabed.The experimental results show that the existence of pipeline increases the wave height near the breaking point;when the pipeline is placed at the position where the water depth ratioΔ =0.36,the wave height increases by nearly 10% compared with that under the condition without pipeline;when the water depth ratioΔdecreases,the maximum scour pit depth at the rear of the pipeline first decreases and then increases;when the pipeline is placed at the position where the water depth ratioΔ=0.47,the maximum scour pit depth at the rear of the pipeline is about 0.2 time of the pipeline diameter,and the least influence is posed on the bed form at this position;when the pipeline gets closer to the breaking point,the position of sandbar formed moves onshore.