海底单层管道铺管端部受力数值分析

Numerical Analysis of Stress on Pipelaying End of Subsea Single-layer Pipeline

针对海底单层管道在铺管过程中张紧器附近出现混凝土配重层开裂,以及钢管、钢筋与混凝土界面滑移过大造成的管道失效问题,采用ANSYS软件对海底单层管道结构进行了非线性有限元数值模拟。基于有限单元的粘结锚固方程、混凝土开裂表征模型以及Houde粘结滑移公式对海底管道配重层混泥土开裂、钢筋滑移和接触应力等进行了数值计算。分析结果表明:针对φ600 mm×9000 mm规格管道的数值模拟结果与工程实际施工过程中管道变形、开裂部位非常接近,并且从管道整体应力分布状况以及不同方向钢筋的应力和滑移分析得出管道受损的机理;研究方法可弥补宏观试验无法直观显示钢筋整体受力状况、裂纹延伸方向、裂纹扩展深度以及界面受力与滑移的不足。研究结果可为海底配重管道的数值模拟技术研究、工程设计和理论研究提供参考。

Aiming at the cracking of the concrete weight coating near the tensioner and the failure of the pipeline caused by the excessive slip of the steel pipe,steel bar and concrete interface in the process of laying the subsea single-layer pipeline,the ANSYS program was used to conduct nonlinear finite element numerical simulation on the structure of the subsea single-layer pipeline.Based on the bond anchorage equation of finite element,the characterization model of concrete cracking,and the Houde bond-slip formula,numerical calculation was conducted on the concrete weight coating cracking,steel bar slippage and contact stress of the subsea pipeline.The analysis results show that the numerical simulation results ofφ600 mm×9000 mm pipeline are very close to the deformation and cracking parts of the pipeline in the actual construction process,and the mechanism of pipeline damage is obtained from analysis on the overall stress distribution of the pipeline and the stress and slip of steel bars in different directions;the study method can make up for the deficiency that the macroscopic test cannot visually display the overall stress state of the steel bar,the crack extension direction and propagation depth,and the interface stress and slippage.The study results provide reference for engineering design and theoretical research of subsea pipelines.