海底柔性管道铺设设计与分析技术研究

发布时间：2019-02-14 08:12

【摘要】：海底柔性管道的铺设是管道正式投入使用过程中最为关键的一个步骤,对于整个海底建设工程而言至关重要。水平式铺设方法因具有结构形式简单、耗资小以及铺设效率高等优点而得到广泛应用。水平式铺设过程中,上弯段管道部分是整个铺设线型中最危险的区域,其最容易发生的失效模式为径向挤压失效。本文应用自然悬链线理论,针对水平式铺设过程的整体线型,得到了上弯段管道的张力、曲率以及径向挤压力的理论表达式。之后,应用专业的海洋管道设计分析软件Orcaflex对水平式铺设过程进行了数值仿真,主要的研究内容及成果为： (1)不同铺设水深下,上弯段管道承受的径向挤压力的整体分布形式是一致的,这种分布形式几乎不受波浪方向和波浪高度的影响；并且随着水深的增加,径向挤压力呈现出比较明显的增加趋势。 (2)在铺设水深和波浪高度一定的情况下,波浪方向对上弯段管道径向挤压力的分布影响较小,且在波浪方向为45°时,上弯段管道的径向挤压力最大。 (3)在波浪高度为2.0米到2.5米左右的铺设工况下,上弯段管道的径向挤压力变化幅度较小；当波浪高度达到3.0米时,径向挤压力发生了比较明显的增加。实际中,管道铺设作业涉及到庞大的铺设系统,面临的海洋环境也十分复杂,因此整个系统的运动和受力都具有很强的非线性、耦合性和随机性,理论和数值分析方法很难对其进行完整准确的分析。本文进一步利用半物理仿真实验原理,开展了模拟铺设工况的实验。通过实验,得到的主要结论为： (1)在不同的海洋环境参数下,通过对上弯段管道部分中一点的径向挤压力的分析可知,实验测量结果与数值仿真结果具有较好的对应性,两者随着铺设水深、波浪方向以及波浪高度的不同而表现出比较一致的变化趋势。 (2)在一定的海洋环境参数下,通过对上弯段管道部分同一点的径向挤压力的对比可知,数值解最大,理论解最小,而实验值介于理论解和数值解之间。
[Abstract]:The laying of submarine flexible pipeline is one of the most important steps in the process of the pipeline being put into use, and it is very important for the whole submarine construction project. Horizontal laying method is widely used because of its simple structure, low cost and high laying efficiency. In the horizontal laying process, the upper bend section of pipeline is the most dangerous area in the whole laying line, and the most prone failure mode is radial extrusion failure. Based on the natural catenary theory, the theoretical expressions of the tension, curvature and radial extrusion force of the upward bend pipe are obtained for the integral alignment of the horizontal laying process. After that, the horizontal laying process is simulated with the professional offshore pipeline design and analysis software Orcaflex. The main research contents and results are as follows: (1) under different laying depth, The overall distribution of the radial extrusion force on the upper bend pipe is consistent, and the distribution is almost independent of the direction and height of the wave. With the increase of water depth, the radial extrusion pressure increases obviously. (2) under the condition of constant water depth and wave height, the influence of the wave direction on the radial extrusion force distribution of the upward bend pipe is relatively small, and the radial extrusion force of the upper bend pipe is the largest when the wave direction is 45 掳. (3) when the wave height is about 2.0 m to 2.5 m, the radial extrusion pressure of the upper bend pipe is smaller, and when the wave height reaches 3.0 m, the radial extrusion pressure increases obviously. In practice, pipeline laying involves a huge laying system, and the marine environment is also very complex. Therefore, the motion and force of the whole system are very nonlinear, coupled and random. Theoretical and numerical analysis methods are difficult to complete and accurate analysis. In this paper, the semi-physical simulation experiment principle is used to simulate the laying condition. Through experiments, the main conclusions are as follows: (1) under different marine environmental parameters, the radial extrusion pressure at one point in the upper bend pipeline is analyzed. The experimental results have a good correspondence with the numerical simulation results, and they show a relatively consistent trend with the different water depth, wave direction and wave height. (2) under certain marine environmental parameters, the numerical solution is the largest and the theoretical solution is the smallest, and the experimental value is between the theoretical solution and the numerical solution by comparing the radial extrusion pressure at the same point in the upper curved section pipeline.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P756.2

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