基于向量式有限元方法的长输海底管道不平整度分析

Bottom roughness analysis of long-distance subsea pipeline using the VFIFE method

海管不平整度分析是悬跨海管设计、施工和运行维护过程中的重要环节。基于向量式有限元方法,提出了一种海管不平整度分析新方法。该方法采用UWAPIPE模型模拟管土耦合作用,采用基于区域分解的MPI并行技术以提高计算效率。对我国南海一段经过沙波区的海管进行不平整度分析,得到了海管位形、悬跨状态以及管道内弯矩分布,模拟结果与水下机器人(ROV)调查结果吻合良好。在此基础上,基于大量悬跨数据的统计分析,给出了不同工况对悬跨长度和高度的影响。模拟了危险悬跨海管开挖治理后的状态,结果表明开挖治理不仅能够有效消除悬跨,同时能够大大减小管道内弯矩分布。相关方法可用于海底长输管道的安全预警。

Bottom roughness analysis is a key process in design, construction and operation maintenance of subsea free- spanning pipeline. In this paper, a new analysis procedure is proposed using the vector form intrinsic finite element（VFIFE） method. In this procedure, the UWAPIPE model is used to simulate the pipe-soil interaction, and the domain decomposition MPI parallel computing technique is adopted to increase efficiency. A pipeline through sandwave region in South China Sea is simulated to identify the pipeline configuration, the status of free spanning and the distribution of bending moment. Comparison shows that the simulated results agree with the survey results by remote operated vehicle（ROV）. In this regard, based on the statistical analysis of the free-spanning data, the spanning heights and lengths in different work conditions are determined. Moreover, since free-spanning pipeline is dangerous, pipeline lowering is simulated. Results show that the pipeline lowering method can effectively avoid free-spanning and reduce distribution of bending moment in pipeline. This method may be applied in safety warning for long-distance subsea pipeline. （12 Figures, 24 References）