潮汐冲刷下悬空管道极限悬空长度的数值模拟研究

Numerical simulation of the ultimate length of suspended pipeline under tidal scour

滩海地区的输油管道在常年潮汐冲刷作用下,部分管段周围土体被潮汐搬运形成悬空状态,悬空管段在潮汐的周期性冲刷下极易产生变形断裂,对管道运行安全和维护造成了严重影响。针对上述情况,首先对悬空管道进行应力分析,建立悬空管道静力学分析物理模型,进而根据现场调研选取2种不同管材,4种不同管径的悬空管道为实验对象,共8组,运用Comsol软件对8组悬空管道进行不同悬空长度下的应力应变数值模拟研究,通过与2种不同管材的屈服极限对比,最终得到了8组悬空管道的极限悬空长度,并用Origin Lab软件对悬空长度和应力关系进行了拟合,证实了悬空长度与应力呈线性正相关。实验结论可对类似的现场工况提供理论依据,对悬空管道的检查和维护起到一定的指导作用。

Under the action of perennial tidal scour,the soil around some sections of the oil pipeline in beach area is transported by the tide to form a suspended state,it has a serious impact on the safety of pipeline operation and maintenance.In view of the above,firstly,the stress of the suspended pipeline is analyzed,and the static analysis physical model of the suspended pipeline is established,the stress and strain of 8 groups of suspended pipelines with 4 different diameters were simulated by using Comsol software,by comparing with the yield limits of two different kinds of pipes,the ultimate suspended length of 8 groups of suspended pipes was obtained,and the relation between suspended length and stress was fitted by Origin Lab software,it is proved that the length of suspension is linearly and positively correlated with the stress.The experimental results can provide a theoretical basis for similar working conditions in the field,and play a guiding role in the inspection and maintenance of suspended pipelines.